Managed pressure cementing wellbore pressure control system and method and application, managed pressure cementing system

Abstract

The present invention discloses a pressure-controlled cementing wellbore pressure control system and method and related applications. The system includes: a cementing design module for obtaining basic parameters for cementing engineering simulation calculations, and for different pressure-controlled cementing stages to be simulated, using the working condition simulation design model of the pressure-controlled cementing stage to be simulated to determine the dynamic distribution of wellbore pressure; an automatic control module for adjusting the wellhead back pressure parameters based on the dynamic distribution of wellbore pressure, a pre-selected wellbore pressure control mode and real-time measurement data of the well site to control the wellbore pressure of pressure-controlled cementing. It can perform simulation calculations based on cementing-related parameter information, accurately adjust the wellhead back pressure according to the simulation calculation results to achieve control of the wellbore pressure and ensure the stability of the wellbore pressure; the system can form a complete set of pressure-controlled cementing construction systems together with pressure-controlled cementing hardware equipment, pressure-controlled cementing operation specifications, etc., to support and improve the pressure-controlled cementing process and ensure safe and efficient pressure-controlled cementing operations.

Description

Technical Field

[0001] The present invention relates to the technical field of controlled pressure cementing, and in particular to a controlled pressure cementing wellbore pressure control system and method and application thereof, and a controlled pressure cementing system. Background Art

[0002] In recent years, with the continuous deepening of exploration and development, the geological conditions of oil and gas reservoirs have become increasingly complex. Problems such as the narrow safety density window have led to frequent and complex accidents such as leakage and well kick during cementing, which have had a serious impact on the integrity and safety of the wellbore. Traditional oil and gas well cementing projects have always followed the principle of "centering, clean displacement, stable pressure, and tight sealing". The density of the cement slurry used during the operation is usually higher than the formation pressure coefficient. Excessively high equivalent circulating density can easily make the downhole pressure close to or exceed the formation fracture pressure limit, resulting in complex accidents such as leakage. Controlled pressure cementing technology has been developed on the basis of controlled pressure drilling technology. By adjusting the wellhead back pressure in real time, it can keep the bottomhole pressure constant within the safe density window. It can effectively solve the contradiction between pressure stability and leakage prevention under the conditions of a narrow safe density window, significantly improve cementing quality, and has become a key technology for solving cementing problems in such complex formations. Summary of the Invention

[0003] The inventors of this application have discovered that while pressure-controlled cementing technology can control bottomhole pressure by adjusting wellhead back pressure, the geological conditions in the pressure-controlled cementing construction area are complex, the construction risks are high, and the wellhead back pressure is difficult to accurately control. Therefore, it is necessary to obtain cementing parameter information in real time during the on-site pressure-controlled cementing process, accurately adjust the wellhead back pressure, and ensure that the wellbore pressure remains within a safe pressure window during the cementing process. At the same time, it is necessary to design key operational links such as slurry structure and construction process in advance before the operation, and determine the reasonable application range of the wellhead back pressure value in advance, so as to better adjust the wellhead back pressure and achieve the purpose of effectively controlling bottomhole pressure. However, the existing technology does not have an implementation solution that can monitor and automatically adjust the pressure-controlled cementing process in real time.

[0004] In view of the above problems, the present invention is proposed to provide a pressure-controlled cementing wellbore pressure control system and method and application, and a pressure-controlled cementing system that overcome the above problems or at least partially solve the above problems.

[0005] An embodiment of the present invention provides a wellbore pressure control system for pressure-controlled cementing, comprising: a cementing design module and an automatic control module;

[0006] The cementing design module is used to obtain basic parameters for cementing engineering simulation calculations, including cementing fluid data, well parameters, and pump parameters. Based on the basic parameters, the module uses the working condition simulation design model of the simulated managed pressure cementing stage to determine the dynamic distribution of wellbore pressure.

[0007] The automatic control module is used to adjust the wellhead back pressure parameters based on the determined dynamic distribution of wellbore pressure, the pre-selected wellbore pressure control mode and the real-time measurement data of the well site to control the wellbore pressure of the managed pressure cementing.

[0008] In some optional embodiments, the cementing design module is specifically used to obtain cementing fluid data, well parameters and pump parameters input through the parameter setting interface; the cementing fluid data includes data of fluid substances whose physical form will slowly change with the cementing process; and / or

[0009] The automatic control module is specifically configured to establish a communication connection with a wellsite measurement instrument and receive real-time monitoring data of the wellsite measured by the measurement instrument; the wellsite measurement instrument includes at least one of a mud logger, a PWD, and a third-party measurement tool;

[0010] The real-time monitoring data includes the outlet flow rate, the inlet flow rate, and the real-time pressure in the wellbore.

[0011] In some optional embodiments, based on the managed pressure cementing stage to be simulated being the heavy slurry injection stage of managed pressure drilling:

[0012] The cementing design module is specifically used to call the heavy slurry injection simulation design model for managed pressure drilling; input the managed pressure drilling mode, the physical properties of the heavy slurry and the basic parameters into the managed pressure drilling heavy slurry injection simulation design model to determine the dynamic pressure distribution of the wellbore annulus during the heavy slurry injection process;

[0013] Accordingly, the automatic control module is specifically configured to determine a wellhead back pressure adjustment amount based on the dynamic distribution of pressure in the wellbore, real-time monitored wellbore pressure data and inlet and outlet flow difference data, a measured formation pressure window, and a pre-selected wellbore pressure control mode; and adjust the opening of the throttle valve to adjust the wellhead back pressure value so that the wellbore pressure of the pressure-managed cementing is stabilized within a preset wellbore pressure threshold range, wherein the wellbore pressure threshold range is within the formation pressure window.

[0014] The managed pressure cementing stage to be simulated is the well circulation stage:

[0015] The cementing design module is specifically used to call the managed pressure cementing well circulation simulation design model; input the well circulation drilling tool assembly data and the basic parameter data into the well circulation simulation design model to determine the dynamic pressure distribution of the wellbore annulus during the well circulation process;

[0016] Accordingly, the automatic control module is specifically configured to determine a wellhead back pressure adjustment amount based on the dynamic distribution of pressure in the wellbore, real-time monitored wellbore pressure data and inlet and outlet flow difference data, a measured formation pressure window, and a pre-selected wellbore pressure control mode; and to adjust the opening of the throttle valve to adjust the wellhead back pressure value so that the wellbore pressure of the pressure-managed cementing is stabilized within a preset wellbore pressure threshold range, wherein the wellbore pressure threshold range is within the formation pressure window.

[0017] The managed pressure cementing stage to be simulated is the managed pressure cementing casing stage:

[0018] The cementing design module is specifically used to call the managed pressure cementing casing simulation design model; input the casing running speed, the full well density reduction plan and the basic parameters into the managed pressure cementing casing simulation design model to determine the dynamic pressure distribution of the wellbore annulus during the managed pressure cementing casing running process;

[0019] Accordingly, the automatic control module is specifically configured to determine a wellhead back pressure adjustment amount based on the dynamic distribution of pressure in the wellbore, real-time monitored wellbore pressure data and inlet and outlet flow difference data, a measured formation pressure window, and a pre-selected wellbore pressure control mode; and to adjust the opening of the throttle valve to adjust the wellhead back pressure value so that the wellbore pressure of the pressure-managed cementing is stabilized within a preset wellbore pressure threshold range, wherein the wellbore pressure threshold range is within the formation pressure window.

[0020] The managed pressure cementing stage to be simulated is the managed pressure cementing injection stage:

[0021] The cementing design module is specifically used to call the managed pressure cementing injection simulation design model; input the cementing slurry physical properties, cementing method and basic parameters into the managed pressure cementing injection simulation design model to determine the cementing slurry position and the dynamic pressure distribution of the wellbore annulus during the managed pressure cementing injection process;

[0022] Accordingly, the automatic control module is specifically configured to determine a wellhead pressure back pressure adjustment amount based on the dynamic distribution of pressure in the wellbore, the measured formation pressure window, the pre-selected wellbore pressure control mode, and the real-time monitored wellbore pressure data, the inlet and outlet flow difference data, and the cementing slurry position; adjust the opening of the throttle valve to adjust the wellhead back pressure value, so that the wellbore pressure of the pressure-controlled cementing is stabilized within a preset wellbore pressure threshold range, wherein the wellbore pressure threshold range is within the formation pressure window;

[0023] The managed pressure cementing stage to be simulated is the managed pressure cementing waiting stage:

[0024] The cementing design module is specifically used to call the pressure-controlled cementing and post-setting simulation design model; input the cementing slurry column structure, liquid level and the basic parameters into the pressure-controlled cementing and post-setting simulation design model to determine the dynamic distribution of cement pressure and wellbore annulus pressure under gelation weightlessness;

[0025] Correspondingly, the automatic control module is specifically used to determine the annular space holding pressure value and the corresponding wellhead back pressure adjustment amount during the waiting process based on the dynamic distribution of pressure in the wellbore, cement pressure, measured formation pressure window, pre-selected wellbore pressure control mode, real-time monitored wellbore pressure data and inlet and outlet flow difference data; adjust the opening of the throttle valve to adjust the wellhead back pressure value, so that the wellbore pressure of pressure-controlled cementing is consistent with the determined annular space holding pressure value.

[0026] In some optional embodiments, when the managed pressure cementing stage to be simulated is the managed pressure cementing casing stage, the cementing design module is further used to: use the managed pressure cementing casing simulation design model to determine at least one of the time-varying conditions of the wellhead pressure, the time-varying conditions of the outlet flow rate, and the time-varying conditions of the flow rate and flow pattern at the point of interest; and / or

[0027] When the pressure-controlled cementing stage to be simulated is the pressure-controlled cementing injection stage, the cementing design module is also used to: use the pressure-controlled cementing injection simulation design model to determine at least one of the changes in wellhead pressure and displacement during the cementing injection process, changes in bottomhole pressure during the cementing injection process, changes in flow patterns at the depth of the focus point during the cementing injection process, changes in the fluid positions of each segment during the cementing injection process, and the annular fluid position at a certain moment during the cementing process.

[0028] In some optional embodiments, the cementing design module is further configured to:

[0029] After setting the cementing construction plan and before starting cementing construction, based on the basic parameters of the cementing engineering simulation calculation, the pressure-controlled cementing process leakage prevention and pressure stability analysis model is called to dynamically simulate the set cementing construction plan and simulate the surface dynamic parameters and downhole dynamic parameters of each stage of pressure-controlled cementing.

[0030] In some optional embodiments, the automatic control module is further configured to:

[0031] A wellbore pressure control mode selection interface is provided, and a selected wellbore pressure control mode is activated according to a wellbore pressure control mode selection instruction; the wellbore pressure control mode selection instruction includes information on a wellbore pressure control mode selected according to a pressure-controlled cementing stage and a cementing working state; the wellbore pressure control mode includes one of a bottomhole pressure mode, a wellhead pressure mode, and a manual control mode; wherein:

[0032] Manual control mode is a method of adjusting the bottom hole pressure based on the input control operation instructions;

[0033] The bottom hole pressure mode is a pressure control mode in which the wellhead pressure is adjusted by adjusting the throttle valve of the throttle pry during the well circulation stage and the injection and displacement stage to maintain a stable bottom hole pressure.

[0034] The wellhead pressure mode is a pressure control mode in which the bottomhole pressure is kept stable during the tripping and casing running stages by adjusting the backpressure pry throttle valve and using the backpressure compensation system to compensate for part of the annular pressure loss.

[0035] In some optional embodiments, the automatic control module is further configured to:

[0036] A wellbore pressure emergency management mode selection interface is provided. According to the management mode selection instruction, the corresponding wellbore pressure emergency management mode is started. The emergency management mode includes at least one of a main / standby valve switching mode, an expert mode, and a parking mode.

[0037] The main / standby valve switching requires a main / standby valve switching mode, in which the main throttle valve is closed and the standby throttle valve is started;

[0038] Expert mode is a mode in which some special parameters are not allowed to be changed;

[0039] The parking mode is a mode in which the pneumatic flat valve is closed to reduce the back pressure value to 0 in an emergency.

[0040] In some optional embodiments, the automatic control module is further configured to:

[0041] If lost circulation is detected based on real-time measurement data from the well site, the level of warning for lost circulation is determined based on the amount of lost circulation, an early warning is issued, a micro-flow loss mode is activated, and wellhead back pressure parameters are adjusted until lost circulation ceases; and / or

[0042] If overflow is determined to have occurred based on real-time measurement data at the well site, the overflow warning level is determined based on the overflow volume and an early warning is issued. The micro-flow overflow mode is activated and the wellhead back pressure parameters are adjusted until the overflow stops.

[0043] In some optional embodiments, the automatic control module is further configured to display, through a human-computer interaction interface, basic parameters, inlet and outlet flow rates, dynamic distribution of wellbore pressure, and other real-time monitoring data at different pressure-controlled cementing stages under different pressure control modes; and the cementing design module is further configured to display, through a human-computer interaction interface, simulation calculation results of wellbore pressure at different pressure-controlled cementing stages;

[0044] The human-computer interaction interface includes a system main interface, a parameter monitoring interface, a parameter setting interface and a working condition simulation display interface.

[0045] In some optional embodiments, the system main interface includes a throttling skid and back pressure skid status display area, a parameter real-time monitoring area, a dynamic curve display area, an operation mode switching area, an operation mode display area, and an abnormal alarm area.

[0046] In some optional embodiments, the throttle skid and back pressure skid status display area is used to display an intuitive two-dimensional graphic of the entire managed pressure cementing equipment pipeline operation status, and the working status of each throttle valve and pressure pipeline is displayed in different colors;

[0047] The parameter real-time monitoring area includes a wellhead pressure control parameter column, an actual measured pressure column, a flow monitoring column, and a depth monitoring column;

[0048] The dynamic curve display area is used to display the detection parameters in the form of a dynamic curve;

[0049] The operation mode switching area is used to provide a wellbore pressure control mode and a wellbore pressure emergency management mode for the user to select and switch;

[0050] The operation mode display area is used to identify the operation mode and working status of the current working condition;

[0051] The abnormal alarm area includes abnormal alarm parameter monitoring and prompt box.

[0052] In some optional embodiments, the parameter monitoring interface includes: a real-time parameter monitoring curve bar, a real-time parameter display area, a real-time parameter statistical parameter display area, a wellbore pressure control mode display area, a bottom hole ECD display bar, a wellhead pressure control value display bar simulated by the cementing design module, and a collected wellhead back pressure actual value display bar.

[0053] In some optional embodiments, the parameter setting interface includes: a cementing fluid data setting column, a well parameter and a pump parameter setting column; including the setting of parameter units and parameter values.

[0054] In some optional embodiments, the working condition simulation display interface includes: display interfaces for the heavy slurry injection stage of pressure-controlled drilling, the well circulation stage, the casing lowering stage of pressure-controlled cementing, the injection and replacement stage of pressure-controlled cementing, the waiting stage for solidification of pressure-controlled cementing, and the leakage prevention and pressure stabilization analysis stage of the pressure-controlled cementing process, which are used to display the simulation calculation results of different stages.

[0055] The embodiment of the present invention further provides a pressure-controlled cementing system, comprising: a wellsite master control machine, a wellsite measuring instrument, and the above-mentioned pressure-controlled cementing wellbore pressure control system;

[0056] The pressure-controlled cementing wellbore pressure control system is connected to the wellsite measuring instrument and / or the wellsite main control machine for obtaining real-time monitoring data of the wellsite from the wellsite measuring tool and / or the wellsite main control machine.

[0057] An embodiment of the present invention further provides a method for controlling wellbore pressure during pressure-controlled cementing, comprising:

[0058] Obtain basic parameters for cementing engineering simulation calculations, including cementing fluid data, well parameters, and pump parameters;

[0059] For different managed pressure cementing stages to be simulated, based on basic parameters, a working condition simulation design model of the managed pressure cementing stage to be simulated is used to determine the dynamic distribution of wellbore pressure;

[0060] Based on the determined dynamic distribution of wellbore pressure, the pre-selected wellbore pressure control mode and real-time measurement data at the well site, the wellhead back pressure parameters are adjusted to control the wellbore pressure for managed pressure cementing.

[0061] In some optional embodiments, obtaining basic parameters for cementing engineering simulation calculations includes:

[0062] The cementing fluid data, well parameters and pump parameters inputted through the parameter setting interface are acquired; the cementing fluid data includes data of a fluid substance whose physical form slowly changes with the cementing process.

[0063] In some optional embodiments, the cementing fluid parameters include at least one of fluid name, fluid type, and fluid physical property parameters;

[0064] The well parameters and pump parameters include at least one of well information input, well trajectory setting, wellbore structure, tubing string setting, formation parameter setting, drilling tool assembly, and pump basic parameter setting.

[0065] In some optional embodiments, the method further includes: obtaining real-time monitoring data of the well site, including:

[0066] Establishing a communication connection with a wellsite measurement instrument to receive real-time monitoring data of the wellsite measured by the measurement instrument; the wellsite measurement instrument includes at least one of a mud logger, a PWD, and a third-party measurement tool;

[0067] The real-time monitoring data includes the outlet flow rate, the inlet flow rate, and the real-time pressure in the wellbore.

[0068] In some optional embodiments, the pressure controlled cementing stage includes at least one of the following: a heavy slurry injection stage for pressure controlled drilling, a well circulation stage, a pressure controlled cementing casing stage, a pressure controlled cementing injection and replacement stage, a pressure controlled cementing waiting stage, and a pressure control cementing process leakage prevention and pressure stability analysis stage.

[0069] In some optional embodiments, the managed pressure cementing stage to be simulated is a heavy slurry injection stage of managed pressure drilling:

[0070] The method comprises: inputting the controlled pressure drilling mode, the physical properties of the heavy slurry, and the basic parameters into the controlled pressure drilling heavy slurry injection simulation design model to determine the dynamic distribution of the wellbore annulus pressure during the heavy slurry injection process; and

[0071] Accordingly, the method of adjusting the wellhead back pressure parameter based on the determined dynamic distribution of wellbore pressure, the pre-selected wellbore pressure control mode, and the real-time measurement data of the well site to control the wellbore pressure of the pressure-managed cementing includes: determining the wellhead back pressure adjustment amount based on the dynamic distribution of pressure in the wellbore, the real-time monitored wellbore pressure data and the inlet and outlet flow difference data, the measured formation pressure window, and the pre-selected wellbore pressure control mode; adjusting the opening of the throttle valve to adjust the wellhead back pressure value so that the wellbore pressure of the pressure-managed cementing is stabilized within a preset wellbore pressure threshold range, wherein the wellbore pressure threshold range is within the formation pressure window;

[0072] The managed pressure cementing stage to be simulated is the well circulation stage:

[0073] The method comprises: inputting the wellbore drilling assembly data and the basic parameter data into the wellbore circulation simulation design model to determine the dynamic distribution of the wellbore annulus pressure during the wellbore circulation process;

[0074] Accordingly, the method of adjusting the wellhead back pressure parameter based on the determined dynamic distribution of wellbore pressure, the pre-selected wellbore pressure control mode, and the real-time measurement data of the well site to control the wellbore pressure of the pressure-managed cementing includes: determining the wellhead back pressure adjustment amount based on the dynamic distribution of pressure in the wellbore, the real-time monitored wellbore pressure data and the inlet and outlet flow difference data, the measured formation pressure window, and the pre-selected wellbore pressure control mode; adjusting the opening of the throttle valve to adjust the wellhead back pressure value so that the wellbore pressure of the pressure-managed cementing is stabilized within a preset wellbore pressure threshold range, wherein the wellbore pressure threshold range is within the formation pressure window;

[0075] The managed pressure cementing stage to be simulated is the managed pressure cementing casing stage:

[0076] The method comprises: inputting the casing running speed, the whole-well density reduction scheme, and the basic parameters into the controlled pressure cementing casing running simulation design model to determine the dynamic distribution of the wellbore annulus pressure during the controlled pressure cementing casing running process;

[0077] Accordingly, the method of adjusting the wellhead back pressure parameter based on the determined dynamic distribution of wellbore pressure, the pre-selected wellbore pressure control mode, and the real-time measurement data of the well site to control the wellbore pressure of the pressure-managed cementing includes: determining the wellhead back pressure adjustment amount based on the dynamic distribution of pressure in the wellbore, the real-time monitored wellbore pressure data and the inlet and outlet flow difference data, the measured formation pressure window, and the pre-selected wellbore pressure control mode; adjusting the opening of the throttle valve to adjust the wellhead back pressure value so that the wellbore pressure of the pressure-managed cementing is stabilized within a preset wellbore pressure threshold range, wherein the wellbore pressure threshold range is within the formation pressure window;

[0078] The managed pressure cementing stage to be simulated is the managed pressure cementing injection stage:

[0079] The method comprises inputting the physical properties of the cementing slurry, the cementing method and the basic parameters into the controlled pressure cementing displacement simulation design model to determine the dynamic distribution of the cementing slurry position and the pressure in the wellbore annulus during the controlled pressure cementing displacement process;

[0080] Accordingly, the method of adjusting the wellhead back pressure parameter based on the determined dynamic distribution of wellbore pressure, the pre-selected wellbore pressure control mode and the real-time measurement data of the well site to control the wellbore pressure of the pressure-controlled cementing includes: determining the wellhead back pressure adjustment amount based on the dynamic distribution of pressure in the wellbore, the measured formation pressure window and the pre-selected wellbore pressure control mode, as well as the real-time monitored wellbore pressure data, the inlet and outlet flow difference data and the cementing slurry position; adjusting the opening of the throttle valve to adjust the wellhead back pressure value so that the wellbore pressure of the pressure-controlled cementing is stabilized within a preset wellbore pressure threshold range, wherein the wellbore pressure threshold range is within the formation pressure window;

[0081] The controlled pressure cementing stage to be simulated is the controlled pressure cementing waiting stage:

[0082] The method comprises: inputting the cementing slurry column structure, the liquid level height, and the basic parameters into the controlled pressure cementing post-setting simulation design model to determine the dynamic distribution of cement pressure and the pressure in the wellbore annulus under the gelled weightless state;

[0083] Correspondingly, the method adjusts the wellhead back pressure parameters based on the determined dynamic distribution of wellbore pressure, the pre-selected wellbore pressure control mode and the real-time measurement data of the well site to control the wellbore pressure of pressure-controlled cementing, including: determining the annular space holding pressure value and the corresponding wellhead back pressure adjustment amount during the waiting-for-setting process based on the dynamic distribution of pressure in the wellbore, cement pressure, the measured formation pressure window, the pre-selected wellbore pressure control mode, the real-time monitored wellbore pressure data and the inlet and outlet flow difference data; and adjusting the opening of the throttle valve to adjust the wellhead back pressure value so that the wellbore pressure of pressure-controlled cementing is consistent with the determined annular space holding pressure value.

[0084] In some optional embodiments, when the managed pressure cementing stage to be simulated is the managed pressure cementing casing stage, the method further includes: using a managed pressure cementing casing simulation design model to determine at least one of the time-varying conditions of the wellhead pressure, the time-varying conditions of the outlet flow, and the time-varying conditions of the flow velocity and flow pattern at the point of interest; and / or

[0085] When the pressure-controlled cementing stage to be simulated is the pressure-controlled cementing injection stage, it also includes: using a pressure-controlled cementing injection simulation design model to determine at least one of the changes in wellhead pressure and displacement during the cementing injection process, changes in bottomhole pressure during the cementing injection process, changes in flow patterns at depths of focus points during the cementing injection process, changes in fluid positions in each segment during the cementing injection process, and annular fluid positions at a certain moment during the cementing process; wherein the cementing methods include: one of: casing cementing, tail pipe cementing, inner pipe cementing, tieback cementing, and screen top cementing.

[0086] In some optional embodiments, after setting the cementing construction plan and before starting the cementing construction, it also includes: based on the basic parameters of the cementing engineering simulation calculation, calling the pressure-controlled cementing process leakage prevention and pressure stability analysis model, dynamically simulating the set cementing construction plan, and simulating the ground dynamic parameters and downhole dynamic parameters of each stage of the pressure-controlled cementing.

[0087] In some optional embodiments, the surface dynamic parameters include changes in return flow rate during cementing and changes in wellhead pressure during cementing;

[0088] The downhole dynamic parameters include the change in fluid position in each section of the cementing process, the return speed of the displacement fluid level during the cementing process, the height of the displacement fluid level during the cementing process, and the change in the bottom hole dynamic pressure during the cementing process.

[0089] In some optional embodiments, the method further includes:

[0090] A wellbore pressure control mode selection interface is provided, and a selected wellbore pressure control mode is activated according to a wellbore pressure control mode selection instruction; the wellbore pressure control mode selection instruction includes information on a wellbore pressure control mode selected according to a pressure-controlled cementing stage and a cementing working state; the wellbore pressure control mode includes one of a bottomhole pressure mode, a wellhead pressure mode, and a manual control mode; wherein:

[0091] Manual control mode is a method of adjusting the bottom hole pressure based on the input control operation instructions;

[0092] The bottom hole pressure mode is a pressure control mode in which the wellhead pressure is adjusted by adjusting the throttle valve during the well circulation stage and the injection and displacement stage to maintain a stable bottom hole pressure.

[0093] The wellhead pressure mode is a pressure control mode in which the bottomhole pressure is kept stable during the tripping and casing running stages by adjusting the backpressure pry throttle valve and using the backpressure compensation system to compensate for part of the annular pressure loss.

[0094] In some optional embodiments, the wellhead pressure mode includes a wellhead backpressure operation mode, a standpipe pressure operation mode, and a micro-flow operation mode; and the bottomhole pressure mode includes an annulus target pressure.

[0095] In some optional embodiments, the method further includes:

[0096] A wellbore pressure emergency management mode selection interface is provided. According to the management mode selection instruction, the corresponding wellbore pressure emergency management mode is started. The emergency management mode includes at least one of a main / standby valve switching mode, an expert mode, and a parking mode.

[0097] The main / standby valve switching requires a main / standby valve switching mode, in which the main throttle valve is closed and the standby throttle valve is started;

[0098] Expert mode is a mode in which some special parameters are not allowed to be changed;

[0099] The parking mode is a mode in which the pneumatic flat valve is closed to reduce the back pressure value to 0 in an emergency.

[0100] In some optional embodiments, the method further includes:

[0101] If lost circulation is detected based on real-time measurement data from the well site, the level of warning for lost circulation is determined based on the amount of lost circulation, an early warning is issued, a micro-flow loss mode is activated, and wellhead back pressure parameters are adjusted until lost circulation ceases; and / or

[0102] If overflow is determined to have occurred based on real-time measurement data at the well site, the overflow warning level is determined based on the overflow volume and an early warning is issued. The micro-flow overflow mode is activated and the wellhead back pressure parameters are adjusted until the overflow stops.

[0103] In some optional embodiments, the method further includes:

[0104] The human-computer interaction interface displays basic parameters, inlet and outlet flow rates, dynamic distribution of wellbore pressure, and other real-time monitoring data at different pressure control modes and different managed pressure cementing stages, as well as simulation calculation results of wellbore pressure at different managed pressure cementing stages;

[0105] The human-computer interaction interface includes a system main interface, a parameter monitoring interface, a parameter setting interface and a working condition simulation display interface.

[0106] In some optional embodiments, the system main interface includes a throttling skid and back pressure skid status display area, a parameter real-time monitoring area, a dynamic curve display area, an operation mode switching area, an operation mode display area, and an abnormal alarm area; wherein:

[0107] The choke skid and back pressure skid status display area is used to display the operation status of the entire managed pressure cementing equipment pipeline in an intuitive two-dimensional graphic. The working status of each choke valve and pressure pipeline is displayed in different colors.

[0108] The parameter real-time monitoring area includes a wellhead pressure control parameter column, an actual measured pressure column, a flow monitoring column, and a depth monitoring column;

[0109] The dynamic curve display area is used to display the detection parameters in the form of a dynamic curve;

[0110] The operation mode switching area is used to provide a wellbore pressure control mode and a wellbore pressure emergency management mode for the user to select and switch;

[0111] The operation mode display area is used to identify the operation mode and working status of the current working condition;

[0112] The abnormal alarm area includes abnormal alarm parameter monitoring and prompt box.

[0113] In some optional embodiments, the parameter monitoring interface includes: a real-time parameter monitoring curve bar, a real-time parameter display area, a real-time parameter statistical parameter display area, a wellbore pressure control mode display area, a bottom hole ECD display bar, a wellhead pressure control value display bar simulated by the cementing design module, and a collected wellhead back pressure actual value display bar.

[0114] In some optional embodiments, the parameter setting interface includes: a cementing fluid data setting column, a well parameter and a pump parameter setting column; including the setting of parameter units and parameter values.

[0115] In some optional embodiments, the working condition simulation display interface includes: display interfaces for the heavy slurry injection stage of pressure-controlled drilling, the well circulation stage, the casing lowering stage of pressure-controlled cementing, the injection and replacement stage of pressure-controlled cementing, the waiting stage for solidification of pressure-controlled cementing, and the leakage prevention and pressure stabilization analysis stage of the pressure-controlled cementing process, which are used to display the simulation calculation results of different stages.

[0116] An embodiment of the present invention further provides an application of the above-mentioned managed pressure cementing wellbore pressure control system in managed pressure cementing.

[0117] An embodiment of the present invention further provides a computer storage medium, characterized in that the computer storage medium stores computer executable instructions, and when the computer executable instructions are executed by a processor, the above-mentioned pressure-controlled cementing wellbore pressure control method is implemented.

[0118] An embodiment of the present invention further provides a control device, characterized in that it includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned pressure-controlled cementing wellbore pressure control method when executing the program.

[0119] The beneficial effects of the above technical solutions provided by the embodiments of the present invention include at least:

[0120] The pressure-controlled cementing wellbore pressure control method and system provided by the embodiment of the present invention, for different pressure-controlled cementing stages to be simulated, uses the working condition simulation design model of the pressure-controlled cementing stage to be simulated based on basic parameters to determine the dynamic distribution of wellbore pressure; and adjusts the wellhead back pressure parameters based on the dynamic distribution of wellbore pressure and real-time measurement data of the well site to control the wellbore pressure of pressure-controlled cementing, realizing real-time acquisition of real-time monitoring data related to cementing and automatic adjustment of wellhead pressure. The entire process of pressure-controlled cementing can be simulated and calculated, and the wellbore pressure is dynamically adjusted in combination with real-time monitoring data, accurately controlling the wellhead back pressure to ensure the stability of the wellbore pressure. The system integrates monitoring, control, and simulation, making the pressure-controlled cementing process more scientific and intelligent, and forming an integrated construction system for pressure-controlled cementing construction. The system can form a complete set of pressure-controlled cementing construction systems together with pressure-controlled cementing hardware equipment, pressure-controlled cementing operation specifications, etc., to support and improve the pressure-controlled cementing process and ensure the safe and efficient operation of pressure-controlled cementing.

[0121] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purposes and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings.

[0122] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0123] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0124] Figure 1 Schematic diagram of the structure of a wellbore pressure control system for managed pressure cementing according to an embodiment of the present invention;

[0125] Figure 2 Schematic diagram of the principle of achieving wellbore pressure in pressure-controlled cementing according to an embodiment of the present invention;

[0126] Figure 3 A schematic structural diagram of a managed pressure cementing system according to an embodiment of the present invention;

[0127] Figure 4 This is a flow chart of a wellbore pressure control method for managed pressure cementing in Example 1 of the present invention;

[0128] Figure 5 This is an example diagram of the real-time parameter monitoring interface in the second embodiment of the present invention;

[0129] Figure 6 This is an example diagram of the hydraulic parameter simulation calculation interface in Example 2 of the present invention. DETAILED DESCRIPTION

[0130] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0131] To address the challenges of existing technologies and improve cementing quality and efficiency under complex conditions, embodiments of the present invention provide a wellbore pressure control system and method for managed pressure cementing. This system combines automatic control technology with computer simulation techniques, utilizing computer programming to create a host computer program. This system enables real-time monitoring of managed pressure cementing field data, automatic adjustment of throttle valve opening, and simulation of the entire managed pressure cementing process. The embodiments of the present invention provide a wellbore pressure control system for managed pressure cementing that integrates control, monitoring, and simulation functions, and is of great significance and potential for promoting the scientific and safe operation of managed pressure cementing operations.

[0132] The embodiment of the present invention provides a wellbore pressure control system for pressure controlled cementing, the structure of which is as follows: Figure 1 As shown, it includes: a cementing design module 11 and an automatic control module 12;

[0133] The cementing design module 11 is used to obtain basic parameters for cementing engineering simulation calculations, including cementing fluid data, well parameters, and pump parameters. For different managed pressure cementing stages to be simulated, the module uses the working condition simulation design model of the managed pressure cementing stage to be simulated based on the basic parameters to determine the dynamic distribution of wellbore pressure.

[0134] The automatic control module 12 is used to adjust the wellhead back pressure parameters based on the determined dynamic distribution of wellbore pressure, the pre-selected wellbore pressure control mode and the real-time measurement data of the well site to control the wellbore pressure of the managed pressure cementing.

[0135] Optionally, the automatic control module 12 is further configured to provide a wellbore pressure control mode selection interface, select a wellbore pressure control mode selection instruction according to the wellbore pressure control mode, and start the selected wellbore pressure control mode.

[0136] Optionally, the automatic control module 12 is further configured to provide a wellbore pressure emergency management mode selection interface, and start a corresponding wellbore pressure emergency management mode according to a management mode selection instruction.

[0137] The above system, for different pressure-controlled cementing stages to be simulated, uses the working condition simulation design model of the pressure-controlled cementing stage to be simulated based on basic parameters to determine the dynamic distribution of wellbore pressure; and adjusts the wellhead back pressure parameters based on the dynamic distribution of wellbore pressure and real-time measurement data of the well site to control the wellbore pressure of pressure-controlled cementing, realizing real-time acquisition of real-time monitoring data related to cementing and automatic adjustment of wellhead pressure. The entire process of pressure-controlled cementing can be simulated and calculated, and the wellbore pressure can be dynamically adjusted in combination with the real-time monitoring data, accurately controlling the wellhead back pressure to ensure stable wellbore pressure. It integrates monitoring, control, and simulation, making the pressure-controlled cementing process more scientific and intelligent, and forming an integrated construction system for pressure-controlled cementing construction.

[0138] The above-mentioned pressure-controlled cementing wellbore pressure control system also becomes the architectural principle of the pressure-controlled cementing wellbore pressure control system and design system. Figure 2 As shown, the pressure cementing wellbore pressure control system can realize parameter acquisition and simulation calculation of each stage of pressure cementing through the automatic control module and the automatic control module, and can also realize functions such as wellbore pressure control mode and wellbore pressure emergency management mode. Figure 1 and Figure 2 Describe in detail the functions of each part of the system.

[0139] The cementing design module 11 in the above-mentioned system specifically acquires cementing fluid data, well parameters, and pump parameters input through a parameter setting interface. Cementing fluid data includes data on fluid substances whose physical form slowly changes as the cementing progresses. Cementing fluid parameters include at least one of the following: fluid name, fluid type, and fluid physical properties. Well pump parameters include at least one of the following: well information input, well trajectory settings, wellbore structure, tubing string settings, formation parameter settings, drill tool assembly settings, and basic pump parameter settings.

[0140] After establishing a communication connection with the wellsite measuring instrument in the above system, the automatic control module 12 is specifically used to establish a communication connection with the wellsite measuring instrument and receive real-time monitoring data of the wellsite measured by the measuring instrument; the wellsite measuring instrument includes at least one of a logging instrument, a PWD and a third-party measurement tool; the real-time monitoring data includes the outlet flow, the inlet flow, and the real-time pressure in the wellbore.

[0141] Both the cementing design module 11 and the automatic control module 12 have parameter setting functions, and can provide the user with a parameter setting interface to obtain various parameters input by the user. The automatic control module 12 can also provide a real-time monitoring data acquisition function and display it through the parameter monitoring interface.

[0142] The cementing design module 11 of the aforementioned system can simulate operating conditions and control wellhead backpressure during different pressure-controlled cementing stages to control wellbore pressure. These pressure-controlled cementing stages include at least one of the following: heavy slurry injection for pressure-controlled drilling, wellbore circulation, casing running, injection and replacement, and waiting for solidification during pressure-controlled cementing. The cementing design module 11 can utilize simulation models specific to each pressure-controlled cementing stage to perform operating condition simulation and wellhead backpressure control.

[0143] During the heavy slurry injection phase of the managed pressure drilling, the cementing design module 11 is specifically configured to call a heavy slurry injection simulation design model for the managed pressure drilling based on the fact that the managed pressure cementing phase to be simulated is the heavy slurry injection phase of the managed pressure drilling; input the managed pressure drilling mode, the physical properties of the heavy slurry, and the basic parameters into the heavy slurry injection simulation design model for the managed pressure drilling, and determine the dynamic pressure distribution in the wellbore annulus during the heavy slurry injection process;

[0144] Correspondingly, the automatic control module 12 is specifically used to determine the wellhead back pressure adjustment amount based on the dynamic distribution of pressure in the wellbore, the real-time monitored wellbore pressure data and the inlet and outlet flow difference data, the measured formation pressure window and the pre-selected wellbore pressure control mode; adjust the opening of the throttle valve to adjust the wellhead back pressure value so that the wellbore pressure of the pressure-controlled cementing is stabilized within a preset wellbore pressure threshold range, and the wellbore pressure threshold range is within the formation pressure window.

[0145] For example, managed pressure drilling (MPD) includes three modes: short-range, long-range, and sacrificial mud injection. The heavy slurry injection simulation design model also includes simulations for these three modes. Based on the MPD mode information in the input parameters, the corresponding simulation model is used to perform simulations and determine the pressure distribution in the wellbore annulus. If the wellbore pressure is within the formation pressure window and meets the wellbore pressure range requirements, no adjustment is required. Otherwise, the backpressure adjustment amount is determined. By adjusting the throttle valve of at least one of the choke skid and the backpressure skid, the flow rate at the wellbore inlet and outlet is adjusted to adjust the wellhead backpressure value and maintain stable wellbore pressure. This achieves real-time dynamic automatic adjustment control.

[0146] When adjusting the wellhead back pressure, the adjustment method is determined based on the wellbore pressure control mode, such as directly adjusting the wellbore pressure value or adjusting the wellhead pressure value, flow rate, etc.

[0147] During the managed pressure cementing and well circulation stage, the cementing design module 11 is specifically configured to call a managed pressure cementing and well circulation simulation design model based on the fact that the managed pressure cementing stage to be simulated is the well circulation stage; input the well circulation drilling tool assembly data and basic parameter data into the well circulation simulation design model to determine the dynamic pressure distribution of the wellbore annulus during the well circulation process;

[0148] Correspondingly, the automatic control module 12 is specifically used to determine the wellhead pressure back pressure adjustment amount based on the dynamic distribution of pressure in the wellbore, the real-time monitored wellbore pressure data and the inlet and outlet flow difference data, the measured formation pressure window and the pre-selected wellbore pressure control mode; adjust the opening of the throttle valve to adjust the wellhead back pressure value so that the wellbore pressure of the pressure-controlled cementing is stabilized within a preset wellbore pressure threshold range, and the wellbore pressure threshold range is within the formation pressure window.

[0149] Wellbore pressure control during the wellbore circulation stage also requires consideration of relevant data from the wellbore drilling tool assembly. The simulation design model for this stage considers wellbore hydraulics calculations under the circulation state during simulation calculations. The underlying calculation program logic for the wellbore circulation design combines heat transfer and hydraulics theory, and considers the temperature-pressure coupling relationship of wellbore fluid heat transfer.

[0150] During the managed pressure cementing casing running stage, the cementing design module 11 is specifically configured to call a managed pressure cementing casing running simulation design model based on the fact that the managed pressure cementing stage to be simulated is the managed pressure cementing casing running stage; input the casing running speed, the full-well density reduction plan, and basic parameters into the managed pressure cementing casing running simulation design model to determine the dynamic pressure distribution in the wellbore annulus during the managed pressure cementing casing running process;

[0151] Accordingly, the automatic control module 12 is specifically configured to determine the wellhead pressure back pressure adjustment amount based on the dynamic distribution of pressure in the wellbore, the real-time monitored wellbore pressure data and the inlet and outlet flow difference data, the measured formation pressure window, and the pre-selected wellbore pressure control mode;

[0152] The throttle valve opening is adjusted to adjust the wellhead back pressure value so that the wellbore pressure of the pressure-controlled cementing is stabilized within the preset wellbore pressure threshold range, which is within the formation pressure window.

[0153] At this stage, it is necessary to consider the casing running speed and the full-well density reduction plan. The full-well density reduction can be a pre-planned heavy slurry replacement plan in the wellbore.

[0154] The cementing design module 11 is further configured to use a managed pressure cementing casing simulation design model to determine at least one of the time-varying conditions of wellhead pressure, outlet flow, and flow velocity and flow regime at a point of interest.

[0155] During the managed pressure cementing and replacement phase, the cementing design module 12 is specifically configured to call a managed pressure cementing and replacement simulation design model based on the fact that the managed pressure cementing phase to be simulated is the managed pressure cementing and replacement phase; input the cementing slurry physical properties, cementing method, and basic parameters into the managed pressure cementing and replacement simulation design model to determine the cementing slurry position and the dynamic pressure distribution of the wellbore annulus during the managed pressure cementing and replacement phase;

[0156] Correspondingly, the automatic control module 11 is specifically used to determine the wellhead pressure back pressure adjustment amount based on the dynamic distribution of pressure in the wellbore, the measured formation pressure window and the pre-selected wellbore pressure control mode, as well as the real-time monitored wellbore pressure data, the inlet and outlet flow difference data and the cementing slurry position; adjust the opening of the throttle valve to adjust the wellhead back pressure value, so that the wellbore pressure of the pressure-controlled cementing is stable within a preset wellbore pressure threshold range, and the wellbore pressure threshold range is within the formation pressure window.

[0157] The cementing design module 11 is also used to use the pressure-controlled cementing injection simulation design model to determine at least one of the changes in wellhead pressure and displacement during the cementing injection process, changes in bottomhole pressure during the cementing injection process, changes in flow patterns at depths of key points during the cementing injection process, changes in fluid positions in each segment during the cementing injection process, and annular fluid positions at a certain moment during the cementing process.

[0158] During the managed pressure cementing waiting stage, the cementing design module 11 is specifically configured to call a managed pressure cementing waiting stage simulation design model based on the fact that the managed pressure cementing stage to be simulated is the managed pressure cementing waiting stage; input the cementing slurry column structure, liquid level, and basic parameters into the managed pressure cementing waiting stage simulation design model to determine the dynamic distribution of cement pressure and wellbore annulus pressure under the gelled weightless state;

[0159] Correspondingly, the automatic control module 11 is specifically used to determine the annular pressure holding value and the corresponding wellhead back pressure adjustment amount during the waiting process based on the dynamic distribution of pressure in the wellbore, cement pressure, measured formation pressure window, pre-selected wellbore pressure control mode, real-time monitored wellbore pressure data and inlet and outlet flow difference data; adjust the opening of the throttle valve to adjust the wellhead back pressure value, so that the wellbore pressure of the pressure-controlled cementing is consistent with the determined annular pressure holding value.

[0160] In some optional embodiments, the cementing design module 12 can also perform a full-process simulation of the cementing process. Specifically, after a cementing construction plan is set and before cementing begins, the cementing design module 12 invokes a managed pressure cementing process leak prevention and pressure stabilization analysis model based on the wellbore inlet and outlet flow data and basic parameters used in cementing engineering simulation calculations to dynamically simulate the set cementing construction plan, simulating both surface and downhole dynamic parameters at each stage of the managed pressure cementing process. This full-process dynamic simulation provides a good preview of the entire managed pressure cementing process, allowing for timely adjustments if any issues are identified.

[0161] In some optional embodiments, the system further includes a wellbore pressure control mode management module 13, configured to:

[0162] In response to the wellbore pressure control mode selection instruction, the selected wellbore pressure control mode is started; the wellbore pressure control mode selection instruction includes wellbore pressure control mode information selected according to the pressure-controlled cementing stage and cementing working state; the wellbore pressure control mode includes one of the bottom hole pressure mode, wellhead pressure mode and manual control mode; the manual control mode is generally mainly used during equipment commissioning and initial well control operations, and different control modes can be selected according to different stages and working states of pressure-controlled cementing. Among them:

[0163] Manual control mode is a method of adjusting the bottom hole pressure based on the input control operation instructions;

[0164] The bottom hole pressure mode is a pressure control mode in which the wellhead pressure is adjusted by adjusting the throttle valve of the throttle pry during the well circulation stage and the injection and displacement stage to maintain a stable bottom hole pressure.

[0165] The wellhead pressure mode is a pressure control mode in which the bottomhole pressure is kept stable during the tripping and casing running stages by adjusting the backpressure pry throttle valve and using the backpressure compensation system to compensate for part of the annular pressure loss.

[0166] In some optional embodiments, the system further includes an emergency management mode management module 14, configured to initiate a corresponding wellbore pressure emergency management mode in response to a management mode selection instruction, wherein the emergency management mode includes at least one of a master / standby valve switching mode, an expert mode, and a parking mode; wherein:

[0167] The main / standby valve switching requires a main / standby valve switching mode, in which the main throttle valve is closed and the standby throttle valve is started;

[0168] Expert mode is a mode in which some special parameters are not allowed to be changed;

[0169] The parking mode is a mode in which the pneumatic flat valve is closed to reduce the back pressure value to 0 in an emergency.

[0170] In some optional embodiments, the automatic control module 11 in the system is further configured to, if lost circulation is determined to have occurred based on real-time measurement data from the well site, determine a lost circulation warning level based on the amount of lost circulation and issue a warning, activate a micro-flow lost circulation mode, and adjust wellhead back pressure parameters until lost circulation ceases. This allows for timely warning and adjustment when wellbore lost circulation occurs.

[0171] In some optional embodiments, the automatic control module 11 in the system is further configured to, if overflow is determined to have occurred based on real-time measurement data from the well site, determine an overflow warning level based on the overflow volume and issue a warning, activate a micro-flow overflow mode, and adjust wellhead back pressure parameters until overflow stops, so that timely warnings and adjustments can be made when overflow occurs.

[0172] In some optional embodiments, the automatic control module is further configured to display basic parameters, inlet and outlet flow rates, dynamic distribution of wellbore pressure, and other real-time monitoring data for different pressure-controlled cementing stages under different pressure control modes via a human-computer interaction interface. The cementing design module is further configured to display simulated calculation results of wellbore pressure for different pressure-controlled cementing stages via a human-computer interaction interface. The human-computer interaction interface can be the main interface, parameter monitoring interface, and parameter setting interface associated with the automatic control unit, or the parameter setting interface and operating condition simulation interface associated with the cementing design module. The human-computer interaction interface includes the system main interface, parameter monitoring interface, parameter setting interface, and operating condition simulation display interface.

[0173] The system's main interface includes a choke skid and back-pressure skid status display area, a real-time parameter monitoring area, a dynamic curve display area, an operation mode switching area, an operation mode display area, and an abnormal alarm area. The choke skid and back-pressure skid status display area is used to display an intuitive two-dimensional graphic of the entire pressure-controlled cementing equipment pipeline operation status, with the working status of each choke valve and pressure pipeline displayed in different colors. The real-time parameter monitoring area includes a wellhead pressure control parameter column, an actual measured pressure column, a flow monitoring column, and a depth monitoring column. The dynamic curve display area is used to display the detection parameters in the form of a dynamic curve. The operation mode switching area is used to provide wellbore pressure control mode and wellbore pressure emergency management mode for user selection and switching. The operation mode display area is used to identify the operation mode and working status of the current working condition. The abnormal alarm area includes abnormal alarm parameter monitoring and prompt boxes.

[0174] The parameter monitoring interface includes: real-time parameter monitoring curve bar, real-time parameter display area, real-time parameter statistical parameter display area, wellbore pressure control mode display area, bottom hole ECD display bar, wellhead pressure control value display bar simulated by cementing design module, and collected wellhead back pressure actual value display bar.

[0175] The parameter setting interface includes: cementing fluid data setting column, well parameter and pump parameter setting column; including parameter unit setting and parameter value setting.

[0176] The working condition simulation display interface includes the display interfaces of the heavy slurry injection stage of managed pressure drilling, the well circulation stage, the casing running stage of managed pressure cementing, the injection and replacement stage of managed pressure cementing, the waiting stage for managed pressure cementing, and the leakage prevention and pressure stabilization analysis stage of the managed pressure cementing process, which are used to display the simulation calculation results of different stages.

[0177] The embodiment of the present invention also provides a pressure controlled cementing system, the structure of which is as follows: Figure 3 As shown, it includes: a well site master control machine 2, a well site measuring instrument 3 and a pressure control system 1 for pressure-controlled cementing wellbore;

[0178] The pressure-managed cementing wellbore pressure control system 1 is communicatively connected to the wellsite measuring instruments 3 and / or the wellsite master control unit 2 to obtain real-time monitoring data from the wellsite. The various wellsite measuring instruments and the wellsite master control unit 4 can communicate with each other using a communication protocol compatible with the control system to achieve data transmission.

[0179] Example 1

[0180] The first embodiment of the present invention provides a method for controlling the wellbore pressure of a pressure-controlled cementing well, the process of which is as follows: Figure 4 As shown, the following steps are included:

[0181] Step S101: obtaining basic parameters for cementing engineering simulation calculation, including cementing fluid data, well parameters, and pump parameters.

[0182] Cementing fluid data, well parameters, and pump parameters entered through the parameter setup interface can be retrieved. Cementing fluid data includes data on fluid substances whose physical form slowly changes as the cementing process progresses. Cementing fluid parameters include at least one of the following: fluid name, fluid type, and fluid physical properties. Well and pump parameters include at least one of the following: well information input, well trajectory settings, wellbore structure, tubing string settings, formation parameter settings, drill tool assembly settings, and basic pump parameter settings.

[0183] It can also establish a communication connection with the well site measuring instruments to receive real-time monitoring data of the well site measured by the measuring instruments; the well site measuring instruments include logging instruments, PWD or third-party measurement tools; the real-time monitoring data includes outlet flow, inlet flow, and real-time pressure in the wellbore.

[0184] Step S102: for different managed pressure cementing stages to be simulated, based on basic parameters, a working condition simulation design model of the managed pressure cementing stage to be simulated is used to determine the dynamic distribution of wellbore pressure.

[0185] Step S103: Based on the determined dynamic distribution of wellbore pressure, the pre-selected wellbore pressure control mode and the real-time measurement data of the well site, the wellhead back pressure parameters are adjusted to control the wellbore pressure of the managed pressure cementing.

[0186] In the above method, the managed pressure cementing stage includes at least one of the following: the heavy slurry injection stage for managed pressure drilling, the wellbore circulation stage, the managed pressure cementing casing stage, the managed pressure cementing injection and replacement stage, the managed pressure cementing waiting stage, and the managed pressure cementing process leak prevention and pressure stability analysis stage. In corresponding steps S102 and S103, different simulation and control processes can be executed for different managed pressure cementing stages. The implementation process of steps S102 and S103 is described in detail below for each stage:

[0187] 1) The managed pressure cementing stage to be simulated is the heavy slurry injection stage of managed pressure drilling:

[0188] The controlled pressure drilling mode, physical properties of heavy slurry and basic parameters are input into the heavy slurry injection simulation design model of controlled pressure drilling to determine the dynamic distribution of pressure in the wellbore annulus during the heavy slurry injection process; the wellhead back pressure adjustment amount is determined based on the dynamic pressure distribution in the wellbore, the real-time monitored wellbore pressure data and the inlet and outlet flow difference data, the measured formation pressure window and the pre-selected wellbore pressure control mode; the opening of the throttle valve is adjusted to adjust the wellhead back pressure value so that the wellbore pressure of the controlled pressure cementing is stabilized within the preset wellbore pressure threshold range, and the wellbore pressure threshold range is within the formation pressure window.

[0189] The physical properties of the heavy slurry refer to the physical characteristic parameters of the heavy slurry, including but not limited to rheological pattern, fluid properties, density, viscosity and other parameters.

[0190] 2) The managed pressure cementing stage to be simulated is the managed pressure cementing and well circulation stage:

[0191] The drilling tool assembly data and basic parameter data are input into the wellbore circulation simulation design model to determine the dynamic distribution of pressure in the wellbore annulus during the wellbore circulation process; the wellhead pressure back pressure adjustment amount is determined based on the dynamic pressure distribution in the wellbore, the real-time monitored wellbore pressure data and the inlet and outlet flow difference data, the measured formation pressure window and the pre-selected wellbore pressure control mode; the throttle valve opening is adjusted to adjust the wellhead back pressure value so that the wellbore pressure of the pressure-controlled cementing is stabilized within the preset wellbore pressure threshold range, and the wellbore pressure threshold range is within the formation pressure window.

[0192] The drilling tool assembly data may include relevant parameters of various drilling tools and their combinations used in the drilling cycle stage.

[0193] 3) The managed pressure cementing stage to be simulated is the managed pressure cementing casing stage:

[0194] The casing running speed, full-well density reduction plan, and basic parameters are input into the pressure-controlled cementing casing running simulation design model to determine the dynamic pressure distribution in the wellbore annulus during the pressure-controlled cementing casing running process. The wellhead backpressure adjustment amount is determined based on the dynamic pressure distribution in the wellbore, the real-time monitored wellbore pressure data and the inlet and outlet flow difference data, the measured formation pressure window, and the pre-selected wellbore pressure control mode. The throttle valve opening is adjusted to adjust the wellhead backpressure value so that the wellbore pressure of the pressure-controlled cementing is stabilized within the preset wellbore pressure threshold range, and the wellbore pressure threshold range is within the formation pressure window.

[0195] For the pressure simulation of the wellbore annulus, we can focus on the pressure of some focus points, that is, select the focus points, and determine the change of the annular space pressure at the selected focus points over time, so as to realize the simulation calculation and targeted pressure control for the positions that need attention as focus points.

[0196] During the managed pressure cementing casing stage, the managed pressure cementing casing simulation design model can also be used to determine at least one of the time-varying wellhead pressure, time-varying outlet flow, and time-varying flow velocity and flow pattern at the point of interest.

[0197] 4) The managed pressure cementing stage to be simulated is the managed pressure cementing injection stage:

[0198] The physical properties of the cementing slurry, the cementing method, and basic parameters are input into the pressure-controlled cementing injection simulation design model to determine the dynamic distribution of pressure at the cementing slurry position and in the wellbore annulus during the pressure-controlled cementing injection process. Based on the dynamic pressure distribution in the wellbore, the measured formation pressure window, the pre-selected wellbore pressure control mode, as well as the real-time monitored wellbore pressure data, the inlet and outlet flow difference data, and the cementing slurry position, the wellhead pressure and back pressure adjustment amount are determined. The throttle valve opening is adjusted to adjust the wellhead back pressure value so that the wellbore pressure of the pressure-controlled cementing is stabilized within a preset wellbore pressure threshold range, which is within the formation pressure window.

[0199] During the pressure-controlled cementing and replacement stage, the pressure-controlled cementing and replacement simulation design model can also be used to determine at least one of the changes in wellhead pressure and displacement during the cementing and replacement process, changes in bottomhole pressure during the cementing and replacement process, changes in flow patterns at depths of key points during the cementing and replacement process, changes in fluid positions in each segment during the cementing and replacement process, and the annular fluid position at a certain moment during the cementing process.

[0200] The cementing method includes: casing cementing, liner cementing, inner pipe cementing, tieback cementing and screen top cementing.

[0201] 5) The managed pressure cementing stage to be simulated is the managed pressure cementing waiting stage:

[0202] The cementing slurry column structure, liquid level height and basic parameters are input into the pressure-controlled cementing wait-for-setting simulation design model to determine the dynamic distribution of cement pressure and wellbore annulus pressure under the gelled weightless state. Based on the dynamic pressure distribution in the wellbore, cement pressure, measured formation pressure window, pre-selected wellbore pressure control mode, real-time monitored wellbore pressure data and inlet and outlet flow difference data, the annular space pressure hold-up value and the corresponding wellhead back pressure adjustment amount during the wait-for-setting process are determined. The throttle valve opening is adjusted to adjust the wellhead back pressure value so that the wellbore pressure of the pressure-controlled cementing is consistent with the determined annular space pressure hold-up value.

[0203] In some optional embodiments, the method further includes a pressure-controlled cementing process leak prevention and pressure stabilization analysis phase. After the cementing construction plan is established and before cementing construction begins, the method further includes: based on the basic parameters calculated by the cementing engineering simulation, calling the pressure-controlled cementing process leak prevention and pressure stabilization analysis model to dynamically simulate the established cementing construction plan, thereby simulating the surface dynamic parameters and downhole dynamic parameters at each stage of the pressure-controlled cementing process. The surface dynamic parameters include changes in the return flow rate and wellhead pressure during the cementing process; the downhole dynamic parameters include changes in the fluid position at each stage of the cementing process, the displacement fluid level return rate during the cementing process, the displacement fluid level height during the cementing process, and changes in the bottomhole dynamic pressure during the cementing process.

[0204] In some optional embodiments, the above method also includes determining the well leakage warning level and issuing an early warning based on the amount of well leakage if it is determined that well leakage has occurred based on real-time measurement data from the well site, as well as starting the micro-flow loss mode and adjusting the wellhead back pressure parameters until the well leakage stops.

[0205] In some optional embodiments, the above method also includes determining the overflow warning level and issuing a warning based on the overflow volume if overflow is determined to have occurred based on real-time measurement data from the well site, as well as starting a micro-flow overflow mode and adjusting the wellhead back pressure parameters until the overflow stops.

[0206] In some optional embodiments, the above method also includes: providing a wellbore pressure control mode selection interface, and starting the selected wellbore pressure control mode according to the wellbore pressure control mode selection instruction; the wellbore pressure control mode selection instruction includes wellbore pressure control mode information selected according to the pressure control cementing stage and the cementing working status; the wellbore pressure control mode includes one of the bottom hole pressure mode, the wellhead pressure mode and the manual control mode; wherein: the manual control mode is a way of adjusting the bottom hole pressure based on the input control operation instruction; the bottom hole pressure mode is a pressure control mode in which the throttle valve of the throttle pry is adjusted to adjust the wellhead pressure during the well circulation stage and the injection and replacement stage to maintain the bottom hole pressure stable; the wellhead pressure mode is a pressure control mode in which the throttle valve of the back pressure pry is adjusted to compensate for part of the annulus pressure loss by using the back pressure compensation system during the drilling and casing lowering stage to maintain the bottom hole pressure stable.

[0207] In some optional embodiments, the above method also includes: providing a wellbore pressure emergency management mode selection interface, and starting the corresponding wellbore pressure emergency management mode according to the management mode selection instruction, the emergency management mode including at least one of the main / standby valve switching mode, the expert mode, and the parking mode; wherein: the main / standby valve switching requires a main / standby valve switching mode, in which the main throttle valve is closed and the standby throttle valve is started; the expert mode is a mode in which some specified special parameters are not allowed to be changed; the parking mode is a mode in which the pneumatic flat valve is closed to reduce the back pressure value to 0 in an emergency.

[0208] In some optional embodiments, the method further includes displaying basic parameters, inlet and outlet flow rates, dynamic distribution of wellbore pressure, and other real-time monitoring data for different pressure control modes and different managed pressure cementing stages through a human-computer interaction interface, as well as simulated calculation results of wellbore pressure during different managed pressure cementing stages. For details, see the relevant description in the system section.

[0209] Example 2

[0210] The second embodiment of the present invention specifically describes the above-mentioned cementing pressure-controlled wellbore pressure control system and provides a specific implementation process of the above-mentioned wellbore pressure control method based on the system.

[0211] The pressure-controlled cementing wellbore pressure control system provided by the present invention can enable engineering personnel to monitor the dynamic changes of cementing parameters in real time and accurately adjust the throttle valve opening during pressure-controlled cementing operations, thereby ensuring the accurate application of wellhead back pressure during the pressure-controlled cementing process, ensuring the cementing quality and operation efficiency under complex conditions, and realizing safe and efficient operations in pressure-controlled cementing construction.

[0212] The main architecture of the above-mentioned managed pressure cementing wellbore pressure control and design system is as follows:

[0213] The managed pressure cementing wellbore pressure control system includes an automatic control module and a cementing design module. The automatic control module is used to establish communication with field monitoring data, adjust the throttle valve opening for managed pressure cementing, select the wellbore pressure control mode and backpressure operation mode, and monitor dynamic changes in indicator parameters. The cementing design module can be used as an integrated component with the automatic control module to provide pressure control value recommendations, or it can be used independently as a design module to provide field engineers with a reference for managed pressure cementing designs under multiple operating conditions and parameters.

[0214] The automatic control module provides a human-computer interaction interface, including the system main interface and the real-time parameter monitoring interface. The display content of the system main interface and the real-time parameter monitoring interface can be designed according to needs. On the one hand, it can obtain various input information through human interaction, and on the other hand, it can display various wellbore-related data obtained by the system, including pressure data, flow data, simulation calculation data, etc.

[0215] Specifically, the system interface design includes an automatic control module that includes a main system interface, a real-time parameter monitoring interface for pressure and flow, and a wellbore and engineering parameter setting interface. Corresponding monitoring interfaces and parameter setting interfaces are designed for different wellbore pressure control modes, such as bottomhole pressure mode, wellhead pressure mode, and manual working mode, to precisely control the wellbore pressure during pressure-controlled cementing. Wellhead pressure modes include wellhead back pressure, standpipe pressure, and micro-flow, while bottomhole pressure modes include annulus target pressure. Corresponding monitoring interfaces and parameter setting interfaces are designed for different wellbore pressure emergency management modes, such as master / standby valve mode switching, expert mode, and parking mode, to facilitate emergency management.

[0216] The cementing design module is divided into a wellbore and engineering parameter setting interface and a hydraulic simulation interface for each stage of managed pressure cementing (also known as a hydraulic simulation interface). For example, simulations are performed for various managed pressure cementing modes, such as short-range and long-range trips, and sacrificial mud injection. The interface displays the relevant parameters and simulation results. The parameter setting interface for the two modules can be shared, and input parameters can be shared between both modules. Various well parameter graphs can be plotted, including wellbore structure diagrams, actual drilling trajectory diagrams, and inclination and azimuth curves. Each graph can be displayed in one-dimensional, two-dimensional, and three-dimensional formats. Data across these interfaces is interconnected, and the output results are compared to determine the appropriate range of backpressure values ​​required on-site. This ensures accurate control of wellhead backpressure during managed pressure cementing operations, maintains wellbore pressure within the formation safety window, and improves cementing quality and efficiency in complex geological conditions.

[0217] The system's main interface centers on the operating status of the choke skid and back-pressure skid, providing an intuitive two-dimensional graphical display of the entire managed pressure cementing equipment pipeline operation. The system's main interface also features areas for real-time parameter monitoring, dynamic curve display, operating mode switching, operating mode display, and abnormality alarms.

[0218] The Parameter Monitoring screen is a sub-screen of the main screen, primarily used to display additional parameter change graphs. Users can also save any desired graphs on the screen. The Parameter Monitoring screen can also be independently dragged and dropped onto a split-screen on the field monitor, independent of the Managed Pressure Cementing Wellbore Pressure Control and Design System display screen.

[0219] The parameter setting interface can be divided into two categories according to the purpose of the parameters. The first category is the basic parameters required for hydraulic calculations in cementing projects, and the second category is the transmission parameters required for the system to communicate with on-site logging instruments and / or related third parties.

[0220] The hydraulic parameter calculation interface can not only provide a theoretical basis for the design of wellhead pressure control values ​​for on-site pressure-controlled cementing operations, but also provide on-site engineering personnel with working condition simulations including heavy slurry injection design for pressure-controlled drilling, wellbore pressure analysis during pressure-controlled well circulation, casing design for pressure-controlled cementing, wellbore pressure design during pressure-controlled cementing injection and replacement, wellbore pressure analysis during pressure-controlled cementing waiting for solidification, and leak-proof pressure stabilization analysis during pressure-controlled cementing. It is a functional module that can be used as a whole with the automatic control module to provide pressure control value recommendations, and can also work independently to provide on-site engineering personnel with multi-working condition and multi-parameter pressure-controlled cementing design references.

[0221] The operating steps of the managed pressure cementing wellbore pressure control system are as follows:

[0222] Step 1: Set up communication with the on-site mud logger data. If a Pressure While Drilling (PWD) or other measurement tool is installed below the drill string, this communication setup is also required. After the system starts, the "Stopped" status in the upper right corner of the main interface will be grayed out, indicating that the system has not yet established communication with the controller, mud logger, PWD, and / or related third parties. Communication connection is required.

[0223] Step 2: Set up communication with the wellsite master control unit. Communication between the pressure-managed cementing wellbore pressure control system and the master control unit must comply with the OPC Remote protocol. OPC stands for OLE for Process Control, which in turn stands for Object Linking and Embedding. When communication is complete, the wellsite data source master control unit will display a "√" status, along with the name of the connected master control unit.

[0224] Step 3: Input basic parameters. Data can be divided into two categories based on the type of data being called: The first category is fluid data, whose physical form changes with the cementing process, such as cementing slurry properties, density, and viscosity; the second category is well data and pump parameters, including well depth structure, drill tool assembly, and basic pump parameters.

[0225] Step 4: Conduct simulation calculations for the various stages of managed pressure cementing. This includes heavy slurry injection design for managed pressure drilling, wellbore circulation design, casing design for managed pressure cementing, wellbore pressure design for injection and replacement during managed pressure cementing, wellbore pressure analysis during the waiting period for managed pressure cementing, and pressure stabilization analysis for leak prevention during managed pressure cementing. The calculation results, combined with on-site monitoring data, provide engineers with a theoretical basis for designing managed pressure values.

[0226] Step 5: The throttle valve is adjusted in real time to control the wellbore pressure by controlling the wellhead back pressure.

[0227] During the well circulation and weight slurry pulling out of the hole, a PWD or other measuring tool is installed at the bottom of the drill string. Based on the measurement data of the PWD or other tools, the inlet flow value is obtained by monitoring the flow at the mud pump and back pressure pump, and the outlet flow is obtained by monitoring the high-precision mass flow meter at the outlet. Combined with the monitored inlet and outlet flow difference, the throttle valve opening is adjusted in real time to maintain stable bottomhole pressure. During the well circulation process, the measurement data of the PWD or other tools are used to determine the applied value of the wellhead back pressure on the one hand, and to verify the hydraulic calculation results on the other hand, to ensure more accurate wellbore pressure control in the subsequent formation pressure window test and cementing injection and replacement processes.

[0228] During the pressure-controlled casing lowering and cementing injection process, the wellhead back pressure value is preliminarily determined based on the measured formation pressure window. The inlet flow value is obtained by monitoring the flow at the mud pump, cement truck and back pressure pump. The outlet flow is obtained by monitoring the high-precision mass flow meter at the monitoring outlet. Combined with the inlet and outlet flow difference obtained by monitoring, the throttle valve opening is adjusted in real time to ensure that the wellbore pressure is always within the safe pressure window during the multi-stage cementing fluid injection process.

[0229] The pressure-controlled cementing wellbore pressure control system provides three wellbore pressure control modes, including bottomhole pressure mode, wellhead pressure mode, and manual working mode. In the bottomhole pressure mode, the wellbore pressure control can be adjusted based on the annulus target pressure as the reference physical quantity. In the wellhead pressure mode, the wellbore pressure control can be adjusted based on the wellhead back pressure, riser pressure, and micro-flow as the reference physical quantities. Under the circulation condition, the bottomhole pressure mode is used to adjust the throttle valve of the throttle skid to adjust the wellhead pressure and maintain the bottomhole pressure stable. Under the drilling and casing conditions, the wellhead pressure mode is used to adjust the backpressure skid throttle valve, and the backpressure compensation system is used to compensate for part of the annulus pressure loss to maintain the bottomhole pressure stable. In case of emergency, you can choose emergency management modes such as master-slave valve mode switching, expert mode, and parking mode in the system.

[0230] In the above system, the features of the automatic control module include but are not limited to the following:

[0231] ① Each throttle valve and pipeline has a color mark, and the user can clearly understand the current pressure pipeline operation status on the system;

[0232] ② The system establishes communication protocol connections with on-site mud loggers and / or relevant third parties to ensure real-time optimization of the wellhead back pressure control scheme for managed pressure cementing operations;

[0233] ③ Obtain the inlet flow value by monitoring the flow at the mud pump, cement truck, and back pressure pump, and obtain the outlet flow value by monitoring the outlet with a high-precision mass flow meter. By monitoring the inlet and outlet flow difference in real time, the downhole working conditions during the pressure-controlled cementing operation can be judged;

[0234] ④ The throttle valve opening can be finely adjusted;

[0235] ⑤ Provide three wellbore pressure control modes: bottom hole pressure mode, wellhead pressure mode and manual working mode, and three wellbore pressure emergency management modes: main and standby valve mode switching, expert mode and parking mode;

[0236] ⑥ Provide four different back pressure operation modes under various working conditions of managed pressure cementing: wellhead back pressure, standpipe pressure, annulus target pressure, and micro flow.

[0237] Features of the cementing design module in the above system include but are not limited to the following:

[0238] ① A basic database covering API and non-API casing, API and non-API drill pipes, and a basic database covering cementing equipment and tools for deep, ultra-deep, and complex wells was established;

[0239] ② A dedicated engineering database was built, which includes a basic database that can store user settings, well information data, slurry data, design data, construction data, etc.

[0240] ③ Provide three managed pressure drilling simulation design methods: short-range managed pressure drilling mode, long-range managed pressure drilling mode and sacrificial mud injection;

[0241] ④Support the storage, import, export and management of cementing related data;

[0242] ⑤ Various well parameter diagrams can be drawn, including wellbore structure diagram, actual drilling trajectory diagram, well inclination and azimuth change curves, etc. Each diagram has one-dimensional, two-dimensional, and three-dimensional display forms. If the user does not customize it, the default display is one-dimensional, and other display forms can be selected as needed;

[0243] ⑥The system has multi-user management function, which can save and share the current design;

[0244] ⑦Unit conversion;

[0245] ⑧ Electronic Dictionary of Cementing Terminology

[0246] ⑨ Printing reports can be customized in a variety of ways according to user needs, including: 1) Custom printing (select the content you want to print as needed); 2) Engineering printing (based on the project site template, the system prints the report content according to the project specifications); 3) All printing (all content designed by the system is printed).

[0247] Generally speaking, the system consists of the main system interface, parameter monitoring interface, parameter setting interface, and hydraulic simulation calculation interface. Each interface is interconnected, and the output results are compared to determine the range of back pressure values ​​required on site. The design and detailed functions of each interface are as follows:

[0248] ①System main interface

[0249] After the system starts normally, the user-oriented system main interface is mainly divided into several major areas: throttling skid and back pressure skid status display, real-time parameter monitoring, dynamic curve display, operation mode switching, operation mode display, and abnormal alarm.

[0250] The choke and backpressure skid status displays, located in the center of the system's main interface, provide an intuitive two-dimensional graphical representation of the entire managed pressure cementing equipment pipeline operation. The operating status of each choke valve and pressure pipeline is displayed in different colors to inform the operator. For example, when a pipeline choke valve is green, it indicates that the choke valve is open, providing the set backpressure value for the wellbore annulus, and the pipeline operating line generating backpressure is also displayed in green. When a pipeline choke valve is gray, it indicates that the choke valve is closed, and the line does not generate backpressure. This display allows the operator to clearly understand the operating status of each choke valve and pressure pipeline.

[0251] The system's throttle valve control system utilizes a three-tiered structure: measuring instruments / actuators (valves) - controllers / input / output components - and host computer system control. The throttle valve can be controlled electrically or pneumatically. In pneumatic control, the air source is connected to the on-site rig crew's air pump. Compressed air propels multiple pneumatic pistons within the actuator, transmitting force to the crossbeam and internal curved track, driving the hollow spindle for rotation. The compressed air is then pumped to each cylinder, actuating the valves. The system's main interface provides coarse and fine adjustment modes for throttle valve control. Coarse adjustment increases or decreases the throttle valve opening by 1% at a time, while fine adjustment increases or decreases the throttle valve opening by 0.1% at a time.

[0252] The parameter real-time monitoring bar is located on the left side of the main interface, and mainly includes four main modules: wellhead pressure control parameters, actual measured pressure, flow monitoring, and depth monitoring.

[0253] The main monitoring parameters of the wellhead pressure control parameter module are real-time circulating back pressure and additional back pressure. Under normal circulating conditions, the cementing wellbore pressure needs to be compensated by a certain amount of back pressure value to keep the bottomhole pressure in the safe density window range. The circulating back pressure changes of the wellhead pressure control parameter module can be monitored to monitor the operation of the pressure-controlled cementing throttle valve in real time. Under the conditions of drilling and casing running, the annular friction is reduced compared with the normal circulating conditions. It is necessary to balance the bottomhole pressure and formation pressure by increasing a certain amount of back pressure value, and use the back pressure compensation system to increase the wellhead back pressure and compensate for the annular pressure loss. The additional back pressure changes of the wellhead pressure control parameter module can be monitored to monitor the operation of the pressure-controlled cementing throttle valve in real time.

[0254] The actual pressure measurement module monitors parameters such as riser pressure, wellhead pressure, main channel pressure, auxiliary channel pressure, post-throttling pressure, and on-site pump stroke. The flow monitoring module primarily monitors changes in high-precision flow counter values ​​for cementing slurry headwater and returnwater to determine whether downhole overflow or leakage has occurred. The depth measurement module primarily monitors current well depth and determines bottomhole equivalent density by combining real-time pressure values.

[0255] The Dynamic Curve Display bar, located above the main interface, intuitively displays key monitoring parameters in the form of dynamic curves. The Managed Pressure Cementing Wellbore Pressure Control and Design System defaults to two dynamic display curves: "Pressure-Time" and "Flow-Time." To adjust the dynamic parameter curve variables, click System Monitoring Parameters to automatically change them.

[0256] The "Pre-valve Pressure-Time" curve consists of three curves: Main Channel Pressure, Auxiliary Channel Pressure, and Set Pressure-Time. The set pressure is the theoretical back pressure setting value derived from predicted formation pressure or measured data from other tools such as PWD. The Main Channel Pressure and Auxiliary Channel Pressure are the actual back pressure values ​​of the primary and backup choke valves. By comparing the theoretical back pressure values ​​with the measured back pressure values, the choke valves can be monitored in real time for any anomalies. The "Flow Rate-Time" curve consists of two curves: Outlet Flow Rate and Inlet Flow Rate-Time. The inlet flow value is obtained by monitoring the flow at the mud pump, cement truck, and back-pressure pump. The outlet flow rate is obtained by monitoring the outlet with a high-precision mass flowmeter. The measured inlet and outlet flow differences are combined to adjust the choke valve opening in real time to maintain the bottomhole pressure within the safe density window.

[0257] The operation mode switching bar is located below the main interface. The pressure-controlled cementing wellbore pressure control system provides three wellbore pressure control modes and three wellbore pressure emergency management modes.

[0258] The three wellbore pressure control modes include bottomhole pressure mode, wellhead pressure mode, and manual working mode. The bottomhole pressure mode, wellhead pressure mode, and manual working mode are all pressure control methods when the equipment is operating normally during the pressure-controlled cementing process. On-site engineers are required to select different pressure control modes according to different pressure-controlled cementing stages and working conditions. Among them, the bottomhole pressure mode and wellhead pressure mode are both semi-automatic working modes. In the pressure-controlled cementing wellbore pressure control and design system, the system does not need to automatically identify different types of pressure-controlled cementing downhole working conditions. On-site engineers operate instructions on the system based on parameters that can characterize the changes in wellbore pressure, such as theoretical calculated values ​​or inlet and outlet flow rates. The manual mode is mainly used in the initial equipment debugging and well control operations.

[0259] During the heavy slurry process of pressure-controlled drilling, it is necessary to combine the system hydraulic calculation results or real-time PWD and other tool measurement data to determine the adjustment principle of the throttle valve opening, calculate the injection volume according to the heavy slurry density, set and adjust the pressure control value to ensure that the wellhead control pressure is zero at the end of heavy slurry injection; during the pressure-controlled well circulation process, the on-site engineering personnel finely control the throttle valve opening, and appropriately increase or decrease the throttle valve opening while ensuring the accuracy of wellhead back pressure control in the subsequent cementing and injection process, and explore the formation pressure window range in combination with the measured data of other tools such as PWD; on the other hand, the engineering personnel The system can be set up to use measured data from other tools such as PWD to verify the hydraulic calculation results, ensuring more accurate wellbore pressure control during cementing and injection processes. During pressure-controlled casing and pressure-controlled cementing and injection, the wellhead back pressure value is preliminarily determined based on the measured formation pressure window. The inlet flow value is obtained by monitoring the flow at the mud pump, cement truck and back-pressure pump, and the outlet flow is obtained by monitoring the high-precision mass flow meter at the outlet. Combined with the monitored inlet and outlet flow difference, the throttle valve opening is adjusted in real time to ensure that the wellbore pressure is always within the safe pressure window during multi-stage cementing fluid injection.

[0260] Under the well circulation condition, the throttle valve should be adjusted in the bottom hole pressure mode to adjust the wellhead pressure and keep the bottom hole pressure stable; under the drilling and casing running conditions, the throttle valve should be adjusted in the wellhead pressure mode, and the back pressure compensation system should be used to compensate for part of the annular space pressure loss to keep the bottom hole pressure stable.

[0261] The three wellbore pressure emergency management modes include master / standby valve mode switching, expert mode, and parking mode. The master / standby valve mode switching mode is used in special situations such as when a throttle valve is blocked and online throttle valve replacement is required. It is necessary to activate the standby throttle valve and adjust the throttle valve opening to ensure that the operating parameters are restored to the state when the throttle valve is not blocked, ensuring the stability of the wellhead pressure in the control system emergency. After activating the expert mode, certain special parameters cannot be changed to prevent the misoperation of wellhead back pressure. The parking mode is used to close the pneumatic flat valve with one button in an emergency, reducing the back pressure value to zero, allowing on-site engineering personnel to urgently handle serious and complex underground accidents.

[0262] The operating mode bar on the upper right side of the main interface indicates the current operating status of the managed pressure cementing wellbore pressure control system, including bottomhole pressure mode, wellhead pressure mode, manual mode, throttle valve activation, and back pressure protection. When different wellbore pressure control modes are enabled, the corresponding display bar indicator bar is green; when different throttle valves are open, the corresponding display bar indicator bar is blue; when the back pressure protection prompt is triggered, the display bar indicator bar is red.

[0263] At the bottom right of the main interface is the abnormal alarm parameter monitoring and prompt box. The main monitoring parameters are hydraulic station pressure, hydraulic station temperature, air source pressure and oil tank level.

[0264] ②Parameter monitoring interface

[0265] The parameter monitoring interface is a sub-interface of the main interface, mainly used to display more parameter change curves, and users can save any curves they need on the interface. For the variable selection of the vertical axis of the curve graph, users can add up to three vertical axes for display in each dynamic curve graph as needed. The parameter monitoring interface can also be independently dragged to the field monitor split screen from the pressure-controlled cementing wellbore pressure control and design system display interface. If the user chooses to display the parameter monitoring curve in a split screen, the user can drag any number of dynamic curves, but if the user wants to display the overall display on the original interface of the system, a maximum of four curves can be selected.

[0266] For the parameter curves that users want to save, users can customize the length of the time period to be exported. The system settings can export real-time parameter data, and the exported data is stored in the Data folder as a time series file.

[0267] For all real-time monitoring parameters, the system background is continuously generating real-time storage data files in the form of files, and storing the data files and image files in different folders respectively.

[0268] An example of a parameter monitoring interface is as follows Figure 5 As shown, the lower left is the real-time parameter monitoring curve bar, which is used to display the parameter change curve; the lower right is the display of real-time parameters and statistical data obtained based on the real-time parameters; the upper right is the control pressure mode bar, which is used to display the wellbore pressure control mode; the upper left shows the bottom hole ECD, the wellhead pressure control value simulated by the cementing design module, and the actual value of the wellhead back pressure collected.

[0269] ③Parameter setting interface

[0270] The parameter setting interface of the pressure-managed cementing wellbore pressure control system can be divided into two categories according to the purpose of the parameters. The first category is the basic parameters required for hydraulic calculations in cementing projects, and the second category is the transmission parameters required for communication between the system and the on-site logging instrument and / or related third parties.

[0271] The basic parameters for cementing engineering simulation calculations in the managed pressure cementing wellbore pressure control system are primarily text data, which is passed to the parameter setting module and displayed in the parameter setting interface. Data can be divided into two categories based on the type of data being called: the first category is fluid data, whose physical form slowly changes with the cementing process, such as cementing slurry properties, density, and viscosity; the second category is well data and pump parameters, including well depth configuration, drill tool assembly, and basic pump parameters.

[0272] The parameter settings interface for the managed pressure cementing wellbore pressure control system first requires setting the unit system. The system defaults to API, SI, Mixed API, and API-US Survey Feet. Clicking "Edit → New" creates a new unit system, which the user can then name. After naming the unit system, the newly created unit system (New Unit) appears in the navigation list. Click New Unit and select the unit system for the variable to be changed. The Select Unit window appears on the right, where the user can select the unit they prefer and save it.

[0273] Fluid data primarily includes three sections: fluid name, fluid type, and fluid rheological properties. Options such as adding a new spacer fluid and adding a new cement are located at the top of the interface. Both cement slurry and spacer fluids can select from a variety of fluid types, including Newtonian, Power Law, Bingham, and Herbach. Rheological parameters for different fluid types can be directly entered or obtained using a six-speed rheometer. Cementing fluids should be added in the designed order and displayed on the 2D wellbore diagram.

[0274] The managed pressure cementing drilling data and pump parameter module primarily includes inputting well information, setting well trajectory, wellbore configuration and tubing, formation parameters, and pump parameters. This module facilitates the user to input or retrieve relevant data before designing and analyzing the managed pressure cementing wellbore pressure control system. All user settings can be saved to the local database of the logged-in account. Alternatively, the user can import and use wellbore configurations from other designs directly or modify them based on previous designs.

[0275] However, it's worth noting that the accuracy and completeness of the basic design data directly impacts the feasibility and rationality of the design results. The more comprehensive the basic design data collected for a well, the more reasonable the design results. However, given the potential limitations of field data collection, design can be performed with only the basic data required for calculations. However, the more data input, the more factors are considered during the calculations, leading to more reasonable results.

[0276] The communication connection transmission parameters of the pressure-controlled cementing wellbore pressure control system include transmission delay time, data verification Min, and data verification Max. The relevant transmission parameters can be passed to the communication transmission process for reception and tested before the start of the pressure-controlled cementing operation to calibrate the accuracy and real-time performance of the data transmission. The real-time data display module must ensure that before the start of the pressure-controlled cementing operation, the pressure-controlled cementing wellbore pressure control and design system establishes a complete communication connection with the on-site mud logger and other measurement tool data such as PWD. When the communication protocol is completely correct, the communication of the well site data source master control machine displays the "√" status, and the name of the connected master control machine is displayed in the communication interface. After the pressure-controlled cementing wellbore pressure control and design system is started, if the prompt box in the upper right corner of the main interface displays the "normal operation" status and is displayed in green, it means that the system has established a normal communication connection with the controller, mud logger and / or related third party.

[0277] Communication between the managed pressure cementing wellbore pressure control system and the mud logger must ensure that all transmitted logging data conforms to the standard Wellsite Information Transmission Specification (WITS) format, using protocols such as UDP and TCP / IP. Decoded files that have been transmitted are displayed in real time in the data display drop-down list. The transmitted data table includes columns for transmitted data and index codes. According to the standard WITS format, the transmitted data columns correspond one-to-one with the index codes to ensure data accuracy.

[0278] ④Working condition simulation display interface (hydraulic parameter simulation calculation interface).

[0279] The cementing design module of the pressure-controlled cementing wellbore pressure control system can not only provide a theoretical basis for the design of wellhead pressure control values ​​for on-site pressure-controlled cementing operations, but also provide on-site engineering personnel with working condition simulations including heavy slurry injection design for pressure-controlled drilling, wellbore circulation design, pressure-controlled cementing casing design, wellbore pressure design during pressure-controlled cementing injection and replacement, wellbore pressure analysis during pressure-controlled cementing waiting for solidification, and leak-proof pressure stability analysis during pressure-controlled cementing. It is a functional module that can be used as a whole with the automatic control module to provide pressure control value recommendations, and can also work independently to provide on-site engineering personnel with multi-working condition and multi-parameter pressure-controlled cementing design references.

[0280] The wellbore pressure control system cementing design module provides a variety of well parameter display options and display forms, which can generate a variety of well parameter maps including wellbore structure map, actual drilling trajectory map, well inclination angle and azimuth angle, etc. Each graph has one-dimensional, two-dimensional and three-dimensional display forms. If the user does not customize it, the system defaults to one-dimensional display. The user can choose other display forms according to the needs later. An example of the working condition simulation display section is as follows Figure 6 As shown, the left side is an example of a two-dimensional wellbore model, and the right side is an example of a one-dimensional wellbore model, which shows the parameters of each fluid section in the wellbore, the parameters of the fluid interface, the parameters of the point of interest, etc.

[0281] The managed pressure drilling (MPD) simulation design includes the entire process from MPD pulling to casing shoe, starting heavy slurry injection, and MPD pulling with the heavy slurry cap. The injection volume is calculated based on the heavy slurry density, providing a reasonable wellhead pressure control value for the managed pressure cementing process to ensure zero wellhead pressure at the end of heavy slurry injection. The heavy slurry injection pattern during the MPD process is determined based on the measured formation pressure window, specifically the MPD type (i.e., the heavy slurry injection mode). The hydraulic calculation module provides three MPD pulling modes: short-range, long-range, and sacrificial mud injection. The short-range MPD pulling mode is suitable for formations with a large pressure window and ensures a high drilling speed. The long-range MPD pulling mode is suitable for formations with a large pressure window, offers lower drilling risk, more accurate bottomhole pressure monitoring, and is less prone to spillage during the pulling process. It also prevents slurry mixing in the lower section, making it easier to establish a circulation system when running casing. The sacrificial mud injection MPD pulling mode is suitable for formations with zero or even no window. By reading the heavy slurry type, segmented fluid volume, and segmented fluid density input by the user in the parameter setting interface, the dynamic pressure distribution in the annulus during the heavy slurry injection process is calculated, and the wellbore pressure analysis of the entire heavy slurry injection process is achieved.

[0282] Managed pressure drilling simulation design: once the on-site managed pressure cementing engineers have determined the managed pressure drilling mode and the corresponding fluid properties, they can directly input the corresponding parameters into the hydraulic calculation module to calculate the dynamic pressure distribution in the annulus during the heavy slurry injection process, realize the wellbore pressure analysis of the entire heavy slurry injection process, and provide the wellhead back pressure design value for the drilling process in combination with the formation pressure window.

[0283] The fundamental principle of managed pressure circulation simulation design is the calculation of wellbore hydraulics during circulation. The underlying computational logic of the circulation design integrates heat transfer and hydraulics theory, taking into account the temperature-pressure coupling relationship of wellbore fluid heat transfer to determine the annular pressure distribution during circulation. The application of wellhead backpressure during the managed pressure circulation process is used to test the formation pressure window. Furthermore, it is combined with measurement data from other tools, such as PWD, to calibrate the hydraulic calculation results and ensure precise control of wellbore pressure during the subsequent managed pressure cementing and injection process.

[0284] The managed pressure casing simulation design takes into account the cementing construction site conditions. By compiling a corresponding dynamic simulation program, multiple key parameters are simulated, including: 1) the change of annular pressure at the focus point over time; 2) the change of wellhead pressure over time;

[0285] 3) The change of outlet flow rate over time; 4) The change of flow rate and flow pattern over time at the point of interest; Based on the input fluid parameters, including rheological pattern, density, viscosity, and casing lowering speed, the downhole fluctuating pressure is calculated. The curve display simultaneously shows the annular pressure, formation pressure, and loss pressure along the wellbore depth during the casing lowering process, which can clearly show whether the annular pressure exceeds the critical value during the casing lowering process, causing pressure loss in the formation. During the casing lowering process, the appropriate casing lowering speed value and full-well density reduction plan are given to ensure that the casing lowering process is in a leak-proof and pressure-stable state.

[0286] Controlled pressure casing running simulation design: For example, if the on-site controlled pressure cementing engineers have determined the casing running speed and the full-well density reduction plan, they can directly input the corresponding parameters into the hydraulic calculation module to calculate the dynamic pressure distribution in the annulus during the controlled pressure casing running process, realize the wellbore pressure analysis of the entire controlled pressure casing running process, and provide the wellhead back pressure design value during the casing running process in combination with the formation pressure window.

[0287] The wellbore pressure design simulation for the managed pressure cementing process uses parameters entered in the parameter setting interface, such as the formulation and properties of each cementing slurry, the volume used for each fluid, the density of each fluid, and the return depth, to calculate the pressure distribution of the fluid in the annulus, enabling annular pressure analysis and leak-proof pressure stability analysis during the cementing process. Key calculation parameters include: 1) annular pressure distribution during cementing and replacement; 2) changes in wellhead pressure and displacement during cementing and replacement; 3) changes in bottomhole pressure during cementing and replacement; 4) changes in flow patterns at key depths during cementing and replacement; 5) changes in fluid position within each segment during cementing and replacement; and 6) annular fluid position at a specific moment during cementing.

[0288] In the calculation results display box, the system automatically defaults to three depth points, referred to as "focus points." The system outputs parameters such as the position, pressure, and displacement of the fluid within the well at each focus point. Users can also enter the desired focus point depth according to their needs and display the corresponding calculation results. Users can click the "2D Display" on the right to clearly display the fluid distribution within the wellbore in a 2D wellbore format, helping users verify the accuracy of the input fluid sequence.

[0289] It's worth noting that the wellbore pressure design for the managed pressure cementing process takes into account different cementing methods. Each cementing method corresponds to different input parameters, and users can enter different parameter settings based on the corresponding cementing method. The system's selectable cementing methods include: casing cementing, liner cementing, inner pipe cementing, tieback cementing, and screen top cementing.

[0290] The wellbore pressure design during the pressure-controlled cementing injection process involves, for example, determining the density and rheological properties of the cementing slurry by on-site pressure-controlled cementing engineers. By obtaining displacement data from the cementing site and taking into account the U-tube effect of different fluids migrating through the wellbore during the cementing process, the cementing slurry position and corresponding wellbore pressure at different times can be calculated. This, combined with the formation safety density window, can then provide a reasonable pressure-controlled cementing wellhead backpressure value. The wellbore pressure design during the pressure-controlled cementing waiting-for-setting process considers the changes in the cementing slurry column structure and liquid level, and combines the cementing transient temperature field calculation model and force balance equation to calculate the cement pressure during the gelation weightlessness state. This allows the annular pressure to be designed during the waiting-for-setting process to ensure stable pressure on the formation during the cement slurry weightlessness process.

[0291] The leak prevention and pressure stabilization analysis for the managed pressure cementing process provides an intuitive dynamic simulation analysis function. After setting up a complete cementing operation plan, this function can be invoked to dynamically simulate the entire cementing process. The dynamic simulation parameter panel is divided into two main sections: surface dynamic parameters and downhole dynamic parameters. Surface dynamic parameters include: 1) changes in return flow rate during cementing; 2) changes in wellhead pressure during cementing; downhole dynamic parameters include: 1) changes in fluid position during each cementing stage; 2) return rate of the displacement fluid level during cementing; 3) displacement fluid level height during cementing; and 4) changes in bottomhole dynamic pressure during cementing.

[0292] Generally speaking, the managed pressure cementing wellbore pressure control and design system needs to establish a communication connection with the field logging instrument before performing the managed pressure cementing operation.

[0293] After the Managed Pressure Cementing Wellbore Pressure Control System is activated, if the "Stopped" status appears in gray in the upper right corner of the main interface, this indicates that the system has not yet established a communication connection with the controller, mud logger, and / or related third parties, and a communication connection is required. Communication between the Managed Pressure Cementing Wellbore Pressure Control and Design System and the master control unit must comply with the OPC Remote protocol. When communication is complete, the wellsite data source master control unit communication status will display "√" and the name of the connected master control unit will be displayed.

[0294] Communication between the managed pressure cementing wellbore pressure control and design system and the mud logger must ensure that all transmitted mud logging data is converted to the standard WITS format. Decoded files that have been transmitted are displayed in real time in the data display drop-down list. The transmitted data table includes columns for transmitted data and index codes. According to the standard WITS format, the transmitted data columns correspond one-to-one with the index codes to ensure data accuracy. Transmission requirements must comply with protocols such as UDP and TCP / IP. 0 represents disabled; 1 represents UDP; 2 represents TCP / IP server; and 3 represents TCP / IP client.

[0295] In addition to establishing communication with the on-site mud logger, the pressure-managed cementing wellbore pressure control system must also establish communication connections with relevant third parties such as PWD to obtain real-time downhole pressure data. The communication connection method with relevant third parties such as PWD refers to the communication settings with the mud logger.

[0296] The communication and interaction testing process between the managed pressure cementing wellbore pressure control system, field logging data, and relevant third parties such as PWD mainly includes:

[0297] ① After the on-site managed pressure cementing equipment and system are ready, switch from the normal drilling operation path to the managed pressure cementing direct current line (manual mode);

[0298] ② Test whether the communication and interaction between the integrated pressure controller and the logging data are correct. If the communication is correct, pre-enter the basic parameters in the logging data into the control system of the pressure controller; if not, check the communication equipment and re-debug;

[0299] ③ If other tools such as PWD are installed under the drilling tool, it is necessary to test whether the communication and interaction between the PWD and other tools and the integrated pressure controller are correct. If the communication is correct, you can prepare to switch to the pressure-managed cementing mode; if not, check the communication equipment and re-debug;

[0300] ④After testing is complete, prepare for pressure-controlled cementing operations.

[0301] The application of back pressure value in the pressure control system of managed pressure cementing requires combining hydraulic calculation results or real-time PWD and other tool measurement data to determine the adjustment principle of throttle valve opening. The specific implementation is as follows:

[0302] ① Controlled pressure drilling and heavy slurry pressure: Stop the circulation during the drilling process, and drill the hole by rotating the control head to control the drilling speed. Increase the back pressure to compensate for the wellbore pressure by adjusting the throttle valve opening of the backpressure pump system. During the process of driving the mud cap, adjust the throttle valve opening of the backpressure pump system to ensure the wellhead back pressure until it drops to zero. At the same time, check the inlet and outlet density and inlet and outlet flow rates to determine whether there is overflow or leakage. The inlet flow rate is obtained by monitoring the flow rate at the mud pump, cement truck, and backpressure pump, and the outlet flow rate is obtained by monitoring the outlet high-precision mass flow meter. When the downhole operating conditions are normal, the system main interface automatically pops up the "Ready to Drill" prompt dialog box. Continue drilling by rotating the control head. Ensure that the wellhead pressure is zero after all the downhole tubing has been pulled out.

[0303] ② Drilling Procedure: Due to the presence of a float valve within the drill string, the weight slurry level will rise during drilling compared to when the well is empty. This height difference in weight slurry causes an increase in bottomhole pressure. Therefore, the weight slurry replacement method must be determined based on the distribution of drilling fluids of varying densities within the wellbore after drilling to the bottom of the weight slurry cap, using hydraulic calculations. This method is used if the dynamic equivalent density of the weight slurry replacement after drilling to the bottom of the weight slurry cap is less than the formation's pressure bearing capacity. If it is greater than the formation's pressure bearing capacity, a staged weight slurry replacement procedure is calculated. The pump is turned on to circulate the weight slurry replacement, and the back pressure is gradually increased by adjusting the throttle valve opening of the backpressure pump system. The pump is stopped when the inlet and outlet densities are consistent. Once the well is at the bottom of the weight slurry cap, the pump is turned on again to complete the displacement of all weight slurry, and pressure is controlled as the wellbore is drilled to bottomhole.

[0304] ③ Single-strand connection: After entering the single-strand connection state, the back-pressure pump system throttle valve can be switched to "ratio control," which means that the back-pressure pump system throttle valve is slowly closed at a certain rate while observing the rise in wellhead pressure in preparation for the single-strand connection operation. Single-strand connection refers to a measure taken during the drilling process in oil fields. As drilling progresses, the wellbore continues to deepen, and the drill string must be lengthened in a timely manner. The drill string is mainly composed of drill pipe. During the drilling process, each time the wellbore is deepened by one drill pipe length, a new drill pipe is added to the drill string. This process is called single-strand connection.

[0305] ④ Well circulation and formation pressure window test: During the pressure-controlled well circulation process, on-site engineering personnel finely control the throttle valve opening. On the premise of ensuring the accuracy of wellhead back pressure control during the subsequent cementing and injection process, they appropriately increase or decrease the throttle valve opening and explore the formation pressure window range in combination with the measured data of other tools such as PWD. On the other hand, engineering personnel can set up the system to use the measured data of other tools such as PWD to verify the hydraulic calculation results to ensure more accurate wellbore pressure control during cementing and injection processes.

[0306] ⑤ Micro-flow loss: At the managed pressure cementing site, the inlet flow rate can be obtained by monitoring the flow rates at the mud pump, cement truck, and backpressure pump, and the outlet flow rate can be obtained by monitoring the outlet with a high-precision mass flowmeter. During the managed pressure cementing process, if the outlet flow rate is less than the inlet flow rate, it is possible that lost circulation is occurring downhole. Based on the lost circulation judgment criteria set in the "Automatic Control System Operation Interface" and the amount of lost circulation, the alarm status is determined and the corresponding mode is switched to that mode. According to the backpressure reduction value recommended by the pressure control engineer, the main throttle valve opening is increased to reduce the wellhead backpressure value ΔP. Simultaneously, the mud pump displacement is adjusted to reduce the bottomhole pressure. Meanwhile, the inlet and outlet flow data are recorded until the lost circulation stops. When the "No leakage, continue drilling normally" message appears on the operation interface, the "yellow warning status" is lifted and the drilling status is switched to the "green operating status" for normal drilling. If the lost circulation volume exceeds 1m³, the system immediately switches to manual operation mode and handles the situation according to the red zone requirements of the dynamic well control table. The bottomhole pressure at the time the lost circulation stops is recorded as the upper limit of the formation safety density window.

[0307] ⑥ Micro-flow overflow: Although the cementing slurry should be kept at a relatively high density during the cementing process to prevent overflow or gas invasion when the wellbore pressure is lower than the formation pressure, which will cause the cement slurry to lose weight and affect the cementing quality, if micro-flow overflow occurs during the cementing process, the throttle valve opening must be adjusted in time to ensure that the downhole overflow is eliminated in time. During the cementing process, when overflow is detected, the overflow judgment conditions set in the "automatic control system operation interface" are combined with the size of the overflow to determine which warning state is in, and switch to that mode at the same time; in the "automatic control" operation interface, without causing well leakage, the main throttle valve opening is immediately reduced through the throttle system to increase the wellhead back pressure value ΔP; the inlet flow value is obtained by monitoring the flow at the mud pump, cement truck and back pressure pump, and the outlet flow is obtained by monitoring the high-precision mass flow meter at the monitoring outlet. Determine the overflow status based on the inlet and outlet flow rate differential until the overflow stops and the "No leakage, continue drilling normally" pop-up appears on the operation interface. At this point, the "yellow warning status" is lifted and the normal drilling "green working status" is switched to. Drilling continues while maintaining the bottomhole pressure above the formation pressure ΔP. If downhole gas invasion occurs, a liquid-gas separator must be used to circulate the gas-invaded fluid out of the wellbore. If the H2S detection system alarms, execute the H2S emergency procedure. If the wellbore invasion volume exceeds 1m3, a "red warning" will appear on the "operation interface" and a "warning status, dangerous" pop-up will appear. At this time, quickly switch from bottomhole pressure mode to manual operation mode and proceed according to the requirements in the red zone of the dynamic well control table. Record the bottomhole pressure when the downhole overflow stops as the lower limit of the formation safety density window.

[0308] ⑦ Cementing slurry injection: Enter the "bottomhole pressure control mode", keep the main throttle valve pipeline in normal working condition, close the back pressure pump line control valve, keep the back pressure pump on standby at all times, adjust the main throttle valve opening, adjust the wellhead back pressure in real time, and ensure constant bottomhole pressure. Combined with the formation pressure window test results and hydraulic calculation verification results, the wellbore pressure is calculated in real time, and the recommended value for the wellhead back pressure is given; during the pressure controlled cementing process, the inlet flow value can be obtained by monitoring the flow at the mud pump, cement truck and back pressure pump, and the outlet flow can be obtained by monitoring the high-precision mass flow meter at the monitoring outlet. If the outlet flow is less than the inlet flow, downhole leakage may occur, and the main throttle valve opening needs to be increased to reduce the wellhead back pressure value; if the outlet flow is greater than the inlet flow, downhole overflow may occur, and the main throttle valve opening needs to be reduced to increase the wellhead back pressure value;

[0309] ⑧Throttle valve blockage: If a sharp increase in the pressure difference before and after the throttle valve is detected, the "automatic control system operation interface" pops up a prompt "The pressure difference before and after the throttle valve exceeds the set value, the throttle valve may be blocked", it can be determined that the throttle valve is blocked, and the "main and standby valve switching" is directly started. The standby throttle valve channel is quickly opened, and the manual flat valve and the air-controlled flat valve are opened in turn. The opening size of the throttle valve is adjusted to ensure that the operating parameters are restored to the state when the throttle valve is not blocked. At the same time, the remote control valve upstream of the blocked main throttle valve is closed to isolate the throttle valve.

[0310] ⑨ Failure of other measurement tools such as PWD: When the PWD signal is interrupted during a managed pressure cementing operation, especially during the pressure-controlled operation of a heavy slurry pull-out, the managed pressure cementing engineer must decide whether to apply wellhead backpressure and continue pulling out based on the hydraulic model calculations. Simultaneously, the managed pressure cementing engineer must adjust the throttle valve opening in real time based on the inlet and outlet flow rates to ensure that the bottomhole pressure remains within the safe pressure window. The inlet flow rate is obtained by monitoring the flow rates at the mud pump, cement truck, and backpressure pump, and the outlet flow rate is obtained by monitoring the outlet's high-precision mass flowmeter.

[0311] Based on the same inventive concept, an embodiment of the present invention further provides an application of the above-mentioned managed pressure cementing wellbore pressure control system in managed pressure cementing.

[0312] Based on the same inventive concept, an embodiment of the present invention further provides a computer storage medium storing computer executable instructions. When the computer executable instructions are executed by a processor, the above-mentioned method for controlling wellbore pressure in pressure-controlled cementing is implemented.

[0313] Based on the same inventive concept, an embodiment of the present invention further provides a control device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned pressure-controlled cementing wellbore pressure control method when executing the program.

[0314] Each embodiment in this specification focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referenced to each other.

[0315] This invention utilizes computer programming to create a host computer program, developing a wellbore pressure control and design system for managed pressure cementing that integrates control, monitoring, and design functions. This system enables real-time monitoring of field data, automatic adjustment of throttle valve opening, and simulation of the entire managed pressure cementing process. This system ensures safe and efficient operations during managed pressure cementing, making the process more scientific and intelligent, in line with the broader development trend of intelligent drilling and completion technologies, and possesses replicable and scalable value and significance.

[0316] Currently, there is no wellbore pressure control and design system developed specifically for managed pressure cementing. Completed managed pressure cementing services all use managed pressure drilling technology and equipment. Some related managed pressure cementing hydraulic simulation systems are limited to the design phase and lack both design and control capabilities. More importantly, these products are not connected to the dedicated equipment system for managed pressure cementing, lacking integrated construction capabilities. The wellbore pressure control and design system for managed pressure cementing proposed in this invention combines control, monitoring, and design functions. The system's main functions include automatic pressure control of managed pressure cementing operations and wellbore pressure design and real-time verification. Combined with the dedicated equipment system for managed pressure cementing, it forms a complete managed pressure cementing construction system, providing integrated construction capabilities.

[0317] The wellbore pressure control and design system for managed pressure cementing, as described in this invention, essentially supports and improves the managed pressure cementing process. It is a supporting system that ensures safe and efficient managed pressure cementing operations. Together with managed pressure cementing hardware equipment, managed pressure cementing operating specifications, and other related content, it forms a complete managed pressure cementing construction system. Through the development of this patent, we have independently mastered the core technology of managed pressure cementing, breaking through technical barriers, significantly reducing our reliance on external technologies and achieving the transition from following behind to leading.

[0318] Field trials and widespread application are expected within the next 1-3 years in cementing operations in oil fields in Xinjiang, Sichuan, and Chongqing, as well as offshore development wells. Currently, the downhole complexity of cementing narrow-density window wells increases by over 20% compared to conventional wells, with non-productive time and costs increasing by more than three times. Complexities such as leakage and channeling also increase significantly, significantly increasing non-productive time. The application of the pressure-controlled cementing control system and supporting equipment described in this invention will reduce non-productive time in cementing test and application wells by over 20% within the next 1-3 years, improve overall cementing quality by over 10%, and generate direct economic benefits exceeding 50 million yuan.

[0319] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are contradictory. The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0320] Unless otherwise specifically stated, terms such as process, calculate, compute, determine, display, and the like may refer to the actions and / or processes of one or more processing or computing systems, or similar devices, that manipulate and convert data represented as physical (e.g., electronic) quantities within registers or memories of a processing system into other data similarly represented as physical quantities within the memories, registers, or other such information storage, transmission, or display devices of the processing system. Information and signals may be represented using any of a variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof.

[0321] It should be understood that the specific order or hierarchy of steps in the disclosed processes is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process can be rearranged without departing from the scope of the present disclosure. The accompanying method claims present elements of the various steps in an exemplary order and are not intended to be limited to the specific order or hierarchy described.

[0322] In the foregoing detailed description, various features are grouped together in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that embodiments of the claimed subject matter require more features than are expressly recited in each claim. On the contrary, as reflected in the appended claims, the invention comprises less than all the features of any individual disclosed embodiment. The appended claims are therefore hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.

[0323] Those skilled in the art will also appreciate that the various illustrative logic blocks, modules, circuits, and algorithmic steps described in conjunction with the embodiments herein may be implemented as electronic hardware, computer software, or a combination thereof. In order to clearly illustrate the interchangeability between hardware and software, the various illustrative components, blocks, modules, circuits, and steps described above are generally described around their functions. Whether such functions are implemented as hardware or software depends on the specific application and the design constraints imposed on the entire system. A skilled person may implement the described functions in an adaptable manner for each specific application, but such implementation decisions should not be interpreted as departing from the scope of protection of this disclosure.

[0324] The steps of the methods or algorithms described in conjunction with the embodiments herein may be directly embodied as hardware, software modules executed by a processor, or a combination thereof. The software module may be located in a RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, register, hard disk, removable disk, CD-ROM, or any other form of storage medium well known in the art. An exemplary storage medium is connected to the processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium may also be an integral part of the processor. The processor and storage medium may be located in an ASIC. The ASIC may be located in a user terminal. Of course, the processor and storage medium may also be present in a user terminal as discrete components.

[0325] For software implementation, the techniques described in this application can be implemented using modules (e.g., procedures, functions, etc.) that perform the functions described in this application. These software codes can be stored in a memory unit and executed by a processor. The memory unit can be implemented within the processor or external to the processor. In the latter case, it is communicatively coupled to the processor via various means, which are well known in the art.

[0326] The foregoing description includes examples of one or more embodiments. Of course, it is not possible to describe all possible combinations of components or methods for the purposes of describing the above embodiments, but one of ordinary skill in the art will recognize that the various embodiments may be further combined and arranged. Therefore, the embodiments described herein are intended to encompass all such changes, modifications and variations that fall within the scope of the appended claims. Furthermore, to the extent the term "comprising" is used in the specification or claims, the term is intended to be encompassed in a manner similar to the term "including," as explained in terms of "including," used as a transitional word in the claims. Furthermore, any use of the term "or" in the specification of the claims is intended to mean a "non-exclusive or."

Claims

1. A wellbore pressure control system for pressure-controlled cementing, characterized in that: include: Cementing design module and automatic control module; Cementing design module, used to obtain basic parameters for cementing engineering simulation calculations, including cementing fluid data, well parameters, and pump parameters; For different managed pressure cementing stages to be simulated, based on basic parameters, a working condition simulation design model of the managed pressure cementing stage to be simulated is used to determine the dynamic distribution of wellbore pressure; An automatic control module is used to adjust wellhead back pressure parameters based on the determined dynamic distribution of wellbore pressure, a pre-selected wellbore pressure control mode, and real-time measurement data from the well site to control the wellbore pressure for managed pressure cementing; wherein: The managed pressure cementing stage to be simulated is the heavy slurry injection stage of managed pressure drilling: The cementing design module is specifically used to call the heavy slurry injection simulation design model for managed pressure drilling; input the managed pressure drilling mode, the physical properties of the heavy slurry and the basic parameters into the managed pressure drilling heavy slurry injection simulation design model to determine the dynamic pressure distribution of the wellbore annulus during the heavy slurry injection process; Accordingly, the automatic control module is specifically configured to determine a wellhead back pressure adjustment amount based on the dynamic distribution of pressure in the wellbore, real-time monitored wellbore pressure data and inlet and outlet flow difference data, a measured formation pressure window, and a pre-selected wellbore pressure control mode; and adjust the opening of the throttle valve to adjust the wellhead back pressure value so that the wellbore pressure of the pressure-managed cementing is stabilized within a preset wellbore pressure threshold range, wherein the wellbore pressure threshold range is within the formation pressure window. The managed pressure cementing stage to be simulated is the well circulation stage: The cementing design module is specifically used to call the managed pressure cementing well circulation simulation design model; input the well circulation drilling tool assembly data and the basic parameter data into the well circulation simulation design model to determine the dynamic pressure distribution of the wellbore annulus during the well circulation process; Accordingly, the automatic control module is specifically configured to determine a wellhead back pressure adjustment amount based on the dynamic distribution of pressure in the wellbore, real-time monitored wellbore pressure data and inlet and outlet flow difference data, a measured formation pressure window, and a pre-selected wellbore pressure control mode; and to adjust the opening of the throttle valve to adjust the wellhead back pressure value so that the wellbore pressure of the pressure-managed cementing is stabilized within a preset wellbore pressure threshold range, wherein the wellbore pressure threshold range is within the formation pressure window. The managed pressure cementing stage to be simulated is the managed pressure cementing casing stage: The cementing design module is specifically used to call the managed pressure cementing casing simulation design model; input the casing running speed, the full well density reduction plan and the basic parameters into the managed pressure cementing casing simulation design model to determine the dynamic pressure distribution of the wellbore annulus during the managed pressure cementing casing running process; Accordingly, the automatic control module is specifically configured to determine a wellhead back pressure adjustment amount based on the dynamic distribution of pressure in the wellbore, real-time monitored wellbore pressure data and inlet and outlet flow difference data, a measured formation pressure window, and a pre-selected wellbore pressure control mode; and to adjust the opening of the throttle valve to adjust the wellhead back pressure value so that the wellbore pressure of the pressure-managed cementing is stabilized within a preset wellbore pressure threshold range, wherein the wellbore pressure threshold range is within the formation pressure window. The managed pressure cementing stage to be simulated is the managed pressure cementing injection stage: The cementing design module is specifically used to call the managed pressure cementing injection simulation design model; input the cementing slurry physical properties, cementing method and basic parameters into the managed pressure cementing injection simulation design model to determine the cementing slurry position and the dynamic pressure distribution of the wellbore annulus during the managed pressure cementing injection process; Accordingly, the automatic control module is specifically configured to determine a wellhead pressure back pressure adjustment amount based on the dynamic distribution of pressure in the wellbore, the measured formation pressure window, the pre-selected wellbore pressure control mode, and the real-time monitored wellbore pressure data, the inlet and outlet flow difference data, and the cementing slurry position; adjust the opening of the throttle valve to adjust the wellhead back pressure value, so that the wellbore pressure of the pressure-controlled cementing is stabilized within a preset wellbore pressure threshold range, wherein the wellbore pressure threshold range is within the formation pressure window; The managed pressure cementing stage to be simulated is the managed pressure cementing waiting stage: The cementing design module is specifically used to call the pressure-controlled cementing and post-setting simulation design model; input the cementing slurry column structure, liquid level and the basic parameters into the pressure-controlled cementing and post-setting simulation design model to determine the dynamic distribution of cement pressure and wellbore annulus pressure under gelation weightlessness; Correspondingly, the automatic control module is specifically used to determine the annular space holding pressure value and the corresponding wellhead back pressure adjustment amount during the waiting process based on the dynamic distribution of pressure in the wellbore, cement pressure, measured formation pressure window, pre-selected wellbore pressure control mode, real-time monitored wellbore pressure data and inlet and outlet flow difference data; adjust the opening of the throttle valve to adjust the wellhead back pressure value, so that the wellbore pressure of pressure-controlled cementing is consistent with the determined annular space holding pressure value.

2. The system according to claim 1, wherein The cementing design module is specifically used to obtain cementing fluid data, well parameters and pump parameters input through the parameter setting interface; the cementing fluid data includes data of fluid substances whose physical form will slowly change with the cementing process; and / or The automatic control module is specifically configured to establish a communication connection with a wellsite measurement instrument and receive real-time monitoring data of the wellsite measured by the measurement instrument; the wellsite measurement instrument includes at least one of a mud logger, a PWD, and a third-party measurement tool; The real-time monitoring data includes the outlet flow rate, the inlet flow rate, and the real-time pressure in the wellbore.

3. The system according to claim 1, wherein: When the managed pressure cementing stage to be simulated is the managed pressure cementing casing stage, the cementing design module is further used to: use the managed pressure cementing casing simulation design model to determine at least one of the changes in wellhead pressure over time, the changes in outlet flow over time, and the changes in flow velocity and flow pattern at the point of interest over time; and / or When the pressure-controlled cementing stage to be simulated is the pressure-controlled cementing injection stage, the cementing design module is also used to: use the pressure-controlled cementing injection simulation design model to determine at least one of the changes in wellhead pressure and displacement during the cementing injection process, changes in bottomhole pressure during the cementing injection process, changes in flow patterns at the depth of the focus point during the cementing injection process, changes in the fluid positions of each segment during the cementing injection process, and the annular fluid position at a certain moment during the cementing process.

4. The system according to claim 1, wherein: The cementing design module is also used to: After setting the cementing construction plan and before starting cementing construction, based on the basic parameters of the cementing engineering simulation calculation, the pressure-controlled cementing process leakage prevention and pressure stability analysis model is called to dynamically simulate the set cementing construction plan and simulate the surface dynamic parameters and downhole dynamic parameters of each stage of pressure-controlled cementing.

5. The system according to claim 1, wherein: The automatic control module is further used for: A wellbore pressure control mode selection interface is provided, and a selected wellbore pressure control mode is activated according to a wellbore pressure control mode selection instruction; the wellbore pressure control mode selection instruction includes information on a wellbore pressure control mode selected according to a pressure-controlled cementing stage and a cementing working state; the wellbore pressure control mode includes one of a bottomhole pressure mode, a wellhead pressure mode, and a manual control mode; wherein: Manual control mode is a method of adjusting the bottom hole pressure based on the input control operation instructions; The bottom hole pressure mode is a pressure control mode in which the wellhead pressure is adjusted by adjusting the throttle valve of the throttle pry during the well circulation stage and the injection and displacement stage to maintain a stable bottom hole pressure. The wellhead pressure mode is a pressure control mode in which the bottomhole pressure is kept stable during the tripping and casing running stages by adjusting the backpressure pry throttle valve and using the backpressure compensation system to compensate for part of the annular pressure loss.

6. The system according to claim 1, wherein: The automatic control module is further used for: A wellbore pressure emergency management mode selection interface is provided. According to the management mode selection instruction, the corresponding wellbore pressure emergency management mode is started. The emergency management mode includes at least one of a main / standby valve switching mode, an expert mode, and a parking mode. The main / standby valve switching requires a main / standby valve switching mode, in which the main throttle valve is closed and the standby throttle valve is started; Expert mode is a mode in which some special parameters are not allowed to be changed; The parking mode is a mode in which the pneumatic flat valve is closed to reduce the back pressure value to 0 in an emergency.

7. The system according to claim 1, wherein: The automatic control module is also used for: If lost circulation is detected based on real-time measurement data at the well site, the system will determine the level of lost circulation warning based on the amount of lost circulation, issue a warning, activate the micro-flow loss mode, and adjust the wellhead back pressure parameters until the lost circulation stops. and / or If overflow is determined to have occurred based on real-time measurement data at the well site, the overflow warning level is determined based on the overflow volume and an early warning is issued. The micro-flow overflow mode is activated and the wellhead back pressure parameters are adjusted until the overflow stops.

8. The system according to any one of claims 1 to 7, wherein the automatic control module is further configured to display, through a human-computer interaction interface, basic parameters, inlet and outlet flow rates, dynamic distribution of wellbore pressure, and other real-time monitoring data for different managed pressure cementing stages under different pressure control modes; and the cementing design module is further configured to display, through a human-computer interaction interface, simulation calculation results of wellbore pressure for different managed pressure cementing stages; The human-computer interaction interface includes a system main interface, a parameter monitoring interface, a parameter setting interface and a working condition simulation display interface.

9. The system according to claim 8, wherein the system main interface includes a throttling skid and back pressure skid status display area, a parameter real-time monitoring area, a dynamic curve display area, an operation mode switching area, an operation mode display area, and an abnormal alarm area.

10. The system according to claim 9, wherein the choke skid and back pressure skid status display area is used to display an intuitive two-dimensional graphic of the operation status of the entire managed pressure cementing equipment pipeline, and the working status of each choke valve and pressure pipeline is displayed in different colors; The parameter real-time monitoring area includes a wellhead pressure control parameter column, an actual measured pressure column, a flow monitoring column, and a depth monitoring column; The dynamic curve display area is used to display the detection parameters in the form of a dynamic curve; The operation mode switching area is used to provide a wellbore pressure control mode and a wellbore pressure emergency management mode for the user to select and switch; The operation mode display area is used to identify the operation mode and working status of the current working condition; The abnormal alarm area includes abnormal alarm parameter monitoring and prompt box.

11. The system according to claim 9, wherein the parameter monitoring interface comprises: Real-time parameter monitoring curve bar, real-time parameter display area, real-time parameter statistical parameter display area, wellbore pressure control mode display area, bottom hole ECD display bar, wellhead pressure control value display bar simulated by cementing design module, and collected wellhead back pressure actual value display bar.

12. The system according to claim 9, wherein the parameter setting interface comprises: Cementing fluid data setting column, well parameter and pump parameter setting column; Including the setting of parameter units and parameter values.

13. The system according to claim 9, wherein the working condition simulation display interface comprises: The display interfaces for the heavy slurry injection stage of managed pressure drilling, the well circulation stage, the casing running stage of managed pressure cementing, the injection and replacement stage of managed pressure cementing, the waiting stage for managed pressure cementing, and the leakage prevention and pressure stabilization analysis stage of the managed pressure cementing process are used to display the simulation calculation results of different stages.

14. A managed pressure cementing system, characterized in that: include: A wellsite master control machine, wellsite measuring instruments, and a pressure-controlled cementing wellbore pressure control system according to any one of claims 1 to 13; The pressure-controlled cementing wellbore pressure control system is connected to the wellsite measuring instrument and / or the wellsite main control machine for obtaining real-time monitoring data of the wellsite from the wellsite measuring tool and / or the wellsite main control machine.

15. A method for controlling wellbore pressure during pressure-controlled cementing, characterized in that: include: Obtain basic parameters for cementing engineering simulation calculations, including cementing fluid data, well parameters, and pump parameters; For different managed pressure cementing stages to be simulated, based on basic parameters, the working condition simulation design model of the managed pressure cementing stage to be simulated is used to determine the dynamic distribution of wellbore pressure; based on the determined dynamic distribution of wellbore pressure, the pre-selected wellbore pressure control mode and real-time measurement data at the well site, the wellhead back pressure parameters are adjusted to control the wellbore pressure of managed pressure cementing; wherein: The managed pressure cementing stage to be simulated is the heavy slurry injection stage of managed pressure drilling: Inputting the managed pressure drilling mode, the physical properties of the heavy slurry and the basic parameters into a simulated design model for heavy slurry injection during managed pressure drilling to determine the dynamic pressure distribution in the wellbore annulus during the heavy slurry injection process; Determining a wellhead back pressure adjustment amount based on the dynamic distribution of pressure in the wellbore, real-time monitored wellbore pressure data and inlet and outlet flow rate difference data, a measured formation pressure window, and a pre-selected wellbore pressure control mode; adjusting the opening of the throttle valve to adjust the wellhead back pressure value so that the wellbore pressure for managed pressure cementing is stabilized within a preset wellbore pressure threshold range, wherein the wellbore pressure threshold range is within the formation pressure window; The pressure-controlled cementing stage to be simulated is the well circulation stage: Inputting the drilling assembly data and the basic parameter data into a wellbore circulation simulation design model to determine the dynamic pressure distribution of the wellbore annulus during the wellbore circulation process; Determining a wellhead back pressure adjustment amount based on the dynamic distribution of pressure in the wellbore, real-time monitored wellbore pressure data and inlet and outlet flow rate difference data, a measured formation pressure window, and a pre-selected wellbore pressure control mode; adjusting the opening of the throttle valve to adjust the wellhead back pressure value so that the wellbore pressure during managed pressure cementing is stabilized within a preset wellbore pressure threshold range, wherein the wellbore pressure threshold range is within the formation pressure window; The managed pressure cementing stage to be simulated is the managed pressure cementing casing stage: Inputting the casing running speed, the whole-well density reduction plan and the basic parameters into the managed pressure cementing casing running simulation design model to determine the dynamic pressure distribution of the wellbore annulus during the managed pressure cementing casing running process; Determining a wellhead back pressure adjustment amount based on the dynamic distribution of pressure in the wellbore, real-time monitored wellbore pressure data and inlet and outlet flow rate difference data, a measured formation pressure window, and a pre-selected wellbore pressure control mode; adjusting the opening of the throttle valve to adjust the wellhead back pressure value so that the wellbore pressure during managed pressure cementing is stabilized within a preset wellbore pressure threshold range, wherein the wellbore pressure threshold range is within the formation pressure window; The managed pressure cementing stage to be simulated is the managed pressure cementing injection stage: Input cementing slurry physical properties, cementing methods, and basic parameters into the managed pressure cementing injection simulation design model to determine the cementing slurry position and the dynamic pressure distribution in the wellbore annulus during the managed pressure cementing injection process; Based on the dynamic distribution of pressure in the wellbore, the measured formation pressure window, the pre-selected wellbore pressure control mode, and the real-time monitored wellbore pressure data, the inlet and outlet flow difference data, and the cementing slurry position, the wellhead pressure back pressure adjustment amount is determined; the throttle valve opening is adjusted to adjust the wellhead back pressure value so that the wellbore pressure of the pressure-managed cementing is stabilized within a preset wellbore pressure threshold range, and the wellbore pressure threshold range is within the formation pressure window; The controlled pressure cementing stage to be simulated is the controlled pressure cementing waiting stage: Inputting the cementing slurry column structure, liquid level height and the basic parameters into the managed pressure cementing post-setting simulation design model to determine the dynamic distribution of cement pressure and wellbore annulus pressure under gelation weightlessness; Based on the dynamic distribution of pressure in the wellbore, cement pressure, measured formation pressure window, pre-selected wellbore pressure control mode, real-time monitored wellbore pressure data and inlet and outlet flow difference data, the annular space pressure value and the corresponding wellhead back pressure adjustment amount during the waiting process are determined; the opening of the throttle valve is adjusted to adjust the wellhead back pressure value so that the wellbore pressure of the pressure-controlled cementing is consistent with the determined annular space pressure value.

16. The method according to claim 15, wherein The basic parameters for cementing engineering simulation calculation are obtained, including: The cementing fluid data, well parameters and pump parameters inputted through the parameter setting interface are acquired; the cementing fluid data includes data of a fluid substance whose physical form slowly changes with the cementing process.

17. The method according to claim 16, wherein The cementing fluid data includes at least one of the fluid name, fluid type, and fluid physical property parameters; The well parameters and pump parameters include at least one of well information input, well trajectory setting, wellbore structure, tubing string setting, formation parameter setting, drilling tool assembly, and pump basic parameter setting.

18. The method according to claim 15, wherein Also includes: Obtain real-time monitoring data for the well site, including: Establishing a communication connection with the well site measuring instrument and receiving the real-time monitoring data of the well site measured by the measuring instrument; The wellsite measurement instrument includes at least one of a mud logger, a PWD, and a third-party measurement tool; The real-time monitoring data includes the outlet flow rate, the inlet flow rate, and the real-time pressure in the wellbore.

19. The method according to claim 15, wherein When the managed pressure cementing stage to be simulated is the managed pressure cementing casing stage, the method further includes: using a managed pressure cementing casing simulation design model to determine at least one of a change in wellhead pressure over time, a change in outlet flow over time, and a change in flow velocity and flow pattern at a point of interest over time; and / or When the pressure-controlled cementing stage to be simulated is the pressure-controlled cementing injection stage, it also includes: using a pressure-controlled cementing injection simulation design model to determine at least one of the changes in wellhead pressure and displacement during the cementing injection process, changes in bottomhole pressure during the cementing injection process, changes in flow patterns at depths of focus points during the cementing injection process, changes in fluid positions in each segment during the cementing injection process, and annular fluid positions at a certain moment during the cementing process; wherein the cementing methods include: one of: casing cementing, tail pipe cementing, inner pipe cementing, tieback cementing, and screen top cementing.

20. The method of claim 15, wherein: After setting the cementing construction plan, before starting cementing construction, it also includes: based on the basic parameters of the cementing engineering simulation calculation, calling the pressure-controlled cementing process leakage prevention and pressure stability analysis model, dynamically simulating the set cementing construction plan, and simulating the surface dynamic parameters and downhole dynamic parameters of each stage of pressure-controlled cementing.

21. The method according to claim 20, wherein The surface dynamic parameters include the change in return flow rate during cementing and the change in wellhead pressure during cementing; The downhole dynamic parameters include the change in fluid position in each section of the cementing process, the return speed of the displacement fluid level during the cementing process, the height of the displacement fluid level during the cementing process, and the change in the bottom hole dynamic pressure during the cementing process.

22. The method of claim 15, wherein: Also includes: A wellbore pressure control mode selection interface is provided, and a selected wellbore pressure control mode is activated according to a wellbore pressure control mode selection instruction; the wellbore pressure control mode selection instruction includes information on a wellbore pressure control mode selected according to a pressure-controlled cementing stage and a cementing working state; the wellbore pressure control mode includes one of a bottomhole pressure mode, a wellhead pressure mode, and a manual control mode; wherein: Manual control mode is a method of adjusting the bottom hole pressure based on the input control operation instructions; The bottom hole pressure mode is a pressure control mode in which the wellhead pressure is adjusted by adjusting the throttle valve during the well circulation stage and the injection and displacement stage to maintain a stable bottom hole pressure. The wellhead pressure mode is a pressure control mode in which the bottomhole pressure is kept stable during the tripping and casing running stages by adjusting the backpressure pry throttle valve and using the backpressure compensation system to compensate for part of the annular pressure loss.

23. The method according to claim 22, wherein The wellhead pressure mode includes wellhead back pressure operation mode, riser pressure operation mode, and micro-flow operation mode; the bottom hole pressure mode includes annulus target pressure.

24. The method of claim 15, wherein: Also includes: A wellbore pressure emergency management mode selection interface is provided. According to the management mode selection instruction, the corresponding wellbore pressure emergency management mode is started. The emergency management mode includes at least one of a main / standby valve switching mode, an expert mode, and a parking mode. The main / standby valve switching requires a main / standby valve switching mode, in which the main throttle valve is closed and the standby throttle valve is started; Expert mode is a mode in which some special parameters are not allowed to be changed; The parking mode is a mode in which the pneumatic flat valve is closed to reduce the back pressure value to 0 in an emergency.

25. The method of claim 15, wherein: Also includes: If lost circulation is detected based on real-time measurement data at the well site, the system will determine the level of lost circulation warning based on the amount of lost circulation, issue a warning, activate the micro-flow loss mode, and adjust the wellhead back pressure parameters until the lost circulation stops. and / or If overflow is determined to have occurred based on real-time measurement data at the well site, the overflow warning level is determined based on the overflow volume and an early warning is issued. The micro-flow overflow mode is activated and the wellhead back pressure parameters are adjusted until the overflow stops.

26. The method according to any one of claims 15 to 25, wherein: Also includes: The human-computer interaction interface displays basic parameters, inlet and outlet flow rates, dynamic distribution of wellbore pressure, and other real-time monitoring data at different pressure control modes and different managed pressure cementing stages, as well as simulation calculation results of wellbore pressure at different managed pressure cementing stages; The human-computer interaction interface includes a system main interface, a parameter monitoring interface, a parameter setting interface and a working condition simulation display interface.

27. The method according to claim 26, wherein the system main interface includes a throttling skid and back pressure skid status display area, a parameter real-time monitoring area, a dynamic curve display area, an operation mode switching area, an operation mode display area, and an abnormal alarm area; wherein: The choke skid and back pressure skid status display area is used to display the operation status of the entire managed pressure cementing equipment pipeline in an intuitive two-dimensional graphic. The working status of each choke valve and pressure pipeline is displayed in different colors. The parameter real-time monitoring area includes a wellhead pressure control parameter column, an actual measured pressure column, a flow monitoring column, and a depth monitoring column; The dynamic curve display area is used to display the detection parameters in the form of a dynamic curve; The operation mode switching area is used to provide a wellbore pressure control mode and a wellbore pressure emergency management mode for the user to select and switch; The operation mode display area is used to identify the operation mode and working status of the current working condition; The abnormal alarm area includes abnormal alarm parameter monitoring and prompt box.

28. The method according to claim 26, wherein the parameter monitoring interface comprises: Real-time parameter monitoring curve bar, real-time parameter display area, real-time parameter statistical parameter display area, wellbore pressure control mode display area, bottom hole ECD display bar, wellhead pressure control value display bar simulated by cementing design module, and collected wellhead back pressure actual value display bar.

29. The method according to claim 26, wherein the parameter setting interface comprises: Cementing fluid data setting column, well parameter and pump parameter setting column; Including the setting of parameter units and parameter values.

30. The method according to claim 26, wherein the working condition simulation display interface comprises: The display interfaces for the heavy slurry injection stage of managed pressure drilling, the well circulation stage, the casing running stage of managed pressure cementing, the injection and replacement stage of managed pressure cementing, the waiting stage for managed pressure cementing, and the leakage prevention and pressure stabilization analysis stage of the managed pressure cementing process are used to display the simulation calculation results of different stages.

31. Use of the managed pressure cementing wellbore pressure control system according to any one of claims 1 to 13 in managed pressure cementing.

32. A computer storage medium, characterized in that The computer storage medium stores computer executable instructions, which, when executed by a processor, implement the wellbore pressure control method for pressure-controlled cementing according to any one of claims 15 to 30.

33. A control device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the method for controlling wellbore pressure of pressure-controlled cementing according to any one of claims 15 to 30 is implemented.

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