Double-throttling synchronous fine pressure control system and method with active sand discharging function

Abstract

The invention discloses a double-throttling synchronous fine pressure control system and method with an active sand discharging function, and relates to the technical field of fine pressure control well drilling, the double-throttling synchronous fine pressure control system comprises a split-flow filter which is provided with an inlet, a first outlet, a second outlet and a third outlet; filter screens are arranged on the shunting filter corresponding to the outlet II and the outlet III; a sand containing cavity is formed in the active sand discharging pipeline assembly, and an inlet of the sand containing cavity communicates with the first outlet of the flow dividing filter; a sand discharging valve is mounted on the active sand discharging pipeline assembly; inlets of the main throttling pipeline assembly and the slave throttling pipeline assembly are communicated with an outlet II and an outlet III of the shunt filter in a one-to-one correspondence manner; the control system is electrically connected with the sand discharging valve, the main throttling pipeline assembly and the auxiliary throttling pipeline assembly. The problem of pressure control from the minimum flow to the maximum flow under the global flow is solved, pressure fluctuation caused by blockage of large-particle rock debris is avoided, the stability and reliability of bottom hole pressure control are improved, and the drilling efficiency is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of fine pressure controlled drilling, and in particular to a dual-throttling synchronous fine pressure controlled system and method with an active sand discharge function. Background Art

[0002] In oil and gas drilling projects, stable control of bottomhole pressure is a key factor in ensuring safe and efficient drilling. As an important device for regulating bottomhole pressure, the performance of the precision pressure control manifold directly affects the quality and efficiency of drilling operations.

[0003] Traditional fine pressure control manifolds often consist of throttle valves with fixed throttle diameters to form pressure control channels. Due to the limitations of the throttle valve throttle diameter, the pressure control flow rate of each throttle valve is limited. When faced with high-flow pressure control requirements, fine pressure control can only be achieved by increasing the throttle diameter of the throttle valve. However, increasing the throttle diameter makes it impossible to achieve fine pressure control at low flows, which poses a significant safety hazard to on-site fine pressure control operations. How to simultaneously meet the pressure control requirements of both large and small flows within a single fine pressure control manifold has become a technical challenge that urgently needs to be addressed in the pressure control industry.

[0004] In addition, with the continuous development of drilling technology, drilling operations in deep wells, ultra-deep wells, and complex geological conditions are increasing. Due to factors such as rock bursts and instability in special formations, a large amount of large-particle rock cuttings will be generated. The premise of fine pressure control is that the throttle valve flow channel is unobstructed and unblocked. Traditional fine pressure control manifolds usually use simple filtering devices to deal with solid particles in the drilling fluid, but this method has many limitations. First, it is difficult to effectively intercept larger-sized rock cuttings and sand particles. These solid particles can easily enter the throttle channel and cause the throttle valve to become blocked. Second, when the filter device is gradually blocked by solid particles, manual intervention is often required for cleaning or replacement, which not only increases the complexity and labor intensity of the operation, but may also lead to interruptions in drilling operations and reduce production efficiency.

[0005] In summary, the existing fine pressure control manifold technology has many problems in facing the simultaneous needs of large and small flow rate pressure control, effective automatic sand removal and anti-blocking, and ensuring long-term stable operation. There is an urgent need for an innovative and efficient solution to realize a full-range flow fine pressure control manifold with active sand removal and anti-blocking functions. Summary of the Invention

[0006] In light of this, the present invention proposes a dual-throttle synchronous fine pressure control system and method with active sand removal capabilities. This system aims to address the technical issues of conventional pressure control manifolds, which are unable to provide both fine pressure control for both extreme and extreme flow rates, as well as their inability to effectively and automatically remove sand and prevent blockages. Through a unique structural design and an efficient and accurate dual-valve synchronous pressure control method, the present invention achieves active sensing and automatic blockage removal of solid particles in the drilling fluid, adapting to fine pressure control for both extreme and extreme flow rates, and improving the stability and reliability of bottomhole pressure control.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] In one aspect, the present invention provides a dual-throttling synchronous fine pressure control system with an active sand discharge function, comprising:

[0009] A diverter filter, the diverter filter having an inlet, an outlet 1, an outlet 2 and an outlet 3, and filter screens are installed on the diverter filter corresponding to the outlet 2 and the outlet 3;

[0010] An active sand discharge pipeline assembly, wherein the active sand discharge pipeline assembly has a sand holding cavity, the inlet of the sand holding cavity is connected to the outlet 1 of the diverter filter; a sand discharge valve capable of opening and closing the outlet of the sand holding cavity is installed on the side of the active sand discharge pipeline assembly corresponding to the outlet 1 of the sand holding cavity;

[0011] A main throttle pipeline assembly and a slave throttle pipeline assembly; the inlets of the main throttle pipeline assembly and the slave throttle pipeline assembly are connected to the second outlet and the third outlet of the diverter filter in a one-to-one correspondence;

[0012] A control system is provided, wherein the control system is electrically connected to the sand discharge valve to perform sand discharge control; the control system is electrically connected to the main throttling pipeline assembly and the slave throttling pipeline assembly to perform flow control and pressure control.

[0013] When the dual-throttling synchronous fine pressure control system with active sand discharge function of the present invention is used, the inlet of the diverter filter is used to connect the mud outlet of the blowout preventer; when the sand discharge valve is closed, the mud can be transported from outlet two and outlet three to the corresponding main throttling pipeline assembly and the slave throttling pipeline assembly after entering the diverter filter. Since the filter screens are installed at outlet two and outlet three, only small particles of rock chips and other impurities are allowed to pass into the main throttling pipeline assembly and the slave throttling pipeline assembly. Large particles of rock chips and other impurities continuously enter the sand holding cavity of the active sand discharge pipeline assembly under the impact of the mud flow and are temporarily stored in a centralized manner to avoid clogging the filter screen; when large particles of rock chips and other impurities in the sand holding cavity accumulate to a certain amount or accumulate for a certain period of time, the control system can automatically open the sand discharge valve to allow the mud flow to directly flush the sand holding cavity to discharge the large particles of rock chips and other impurities accumulated therein, thereby effectively preventing the main throttling pipeline assembly and the slave throttling pipeline assembly from being blocked, creating favorable conditions for fine pressure control. When a large amount of mud is required for drilling and fine pressure control is required during the operation, the operator needs to open two throttling branches, that is, open the main throttling pipeline assembly and the slave throttling pipeline assembly, and perform dual throttling synchronous fine pressure control; through the dual throttling synchronous control method, it is possible to accurately achieve dual throttling synchronous fine pressure control under large flow, meeting the pressure control requirements of large mud displacement. When an extremely small flow circulation is required during the operation and a fine pressure control process needs to be performed, the control system will close the slave throttling pipeline assembly and use the main throttling pipeline assembly to achieve fine pressure control under extremely small mud flow. The present invention realizes effective removal of solid particles in the drilling fluid through the active sand removal pipeline assembly to prevent active sand blocking and the synchronous control of dual throttling branches, and adapts to the fine pressure control of the maximum and minimum global flow rates, thereby improving the stability and reliability of bottom hole pressure control.

[0014] As a further improvement of the above technical solution, the active sand discharge pipeline assembly includes an impurity storage and weighing chamber, a flexible pipeline 1 and a flexible pipeline 2; the inner cavity of the impurity storage and weighing chamber is a sand holding cavity; the inlet of the sand holding cavity is connected to and communicated with a port of the flexible pipeline 1, and the other port of the flexible pipeline 1 is connected to and communicated with an outlet 1 of the diverter filter; the outlet of the sand holding cavity is connected to and communicated with a port of the flexible pipeline 2; the other port of the flexible pipeline 2 is connected to and communicated with the inlet of the sand discharge valve;

[0015] The control system is electrically connected to the impurity storage weighing chamber to monitor the impurity storage amount in the sand holding cavity.

[0016] The beneficial effects of the above technical solution are: the impurity storage weighing chamber has the function of actively sensing the accumulation amount of impurities such as rock cuttings in the sand containing cavity; when the impurities such as rock cuttings in the sand containing cavity accumulate to a certain weight (preset weight), the control system can obtain the cumulative weight signal of impurities such as rock cuttings, and then control the opening of the sand discharge valve to automatically remove the blockage. After the sand discharge valve is opened, the mud flow passes through the flexible pipeline 1, the sand containing cavity, the flexible pipeline 2 and the sand discharge valve in turn to flush and discharge the impurities in the sand containing cavity. After the impurities in the sand containing cavity are discharged, the sand discharge valve is closed.

[0017] As a further improvement of the above technical solution, the flexible pipeline 1, the impurity storage weighing chamber and the flexible pipeline 2 are connected in sequence along the length direction to form an active blockage-removing straight-through pipeline.

[0018] The beneficial effect of the above technical solution is that the purpose of constructing an active blockage-removing straight-through pipeline is to make the incoming flow impact force greater and the flushing effect better.

[0019] As a further improvement of the above technical solution, the impurity storage and weighing chamber includes an impurity storage chamber and a weighing unit; the inner cavity of the impurity storage chamber is a sand-containing cavity; the weighing unit is connected to the impurity storage chamber for weighing; the control system is electrically connected to the weighing unit to collect and obtain the weight signal of the accumulated impurities in the sand-containing cavity in real time.

[0020] The beneficial effects of the above technical solution are: since the inlet and outlet of the sand-containing cavity of the impurity storage chamber are connected one-to-one and connected to flexible pipeline 1 and flexible pipeline 2; flexible pipeline 1 and flexible pipeline 2 are flexible high-pressure hoses that can be retracted and deformed, so that the impurity storage chamber can move up and down freely; that is, as the impurities in the sand-containing cavity increase, the impurity storage chamber will move downward under the action of gravity, and then be sensed by the weighing unit, and then the weighing unit can monitor the accumulated amount of impurities in the sand-containing cavity.

[0021] As a further improvement of the above technical solution, the weighing unit is a pressure-sensitive element; the pressure-sensitive element is installed at the lower end of the impurity storage chamber to measure the gravity of the impurity storage chamber in real time.

[0022] The beneficial effect of the above technical solution is that the weighing unit uses a pressure-sensitive element and is supported at the lower end of the impurity storage chamber. Its function is to directly weigh the weight of the impurity storage chamber, and then the accumulated amount of impurities in the sand cavity can be judged according to the weight difference.

[0023] As a further improvement of the above technical solution, the main throttle pipeline assembly includes a pipeline assembly 1 and a main throttle valve; the slave throttle pipeline assembly includes a pipeline assembly 2 and a slave throttle valve;

[0024] The inlet of the pipeline component 1 is connected to and communicates with the outlet 2 of the diverter filter; the main throttle valve is installed on the pipeline component 1 to control the flow;

[0025] The inlet of the second pipeline component is connected to and communicates with the outlet 3 of the diverter filter; the slave throttle valve is installed on the second pipeline component to control the flow;

[0026] The control system electrically connects the master throttle valve and the slave throttle valve to control the opening degrees thereof.

[0027] The beneficial effects of the above technical solution are: the control system can control the opening and closing status and opening size of the main throttle valve and the slave throttle valve, and then perform dual-valve synchronous control under large flow, realize dual-valve master-slave synchronous throttling control under full-range flow, and close the slave throttle valve to only control the main throttle valve to achieve fine pressure control under extremely small mud flow.

[0028] As a further improvement of the above technical solution, the main throttling pipeline assembly further includes valve 1 and valve 2; the slave throttling pipeline assembly further includes valve 3 and valve 4;

[0029] The valve one and the valve two are both installed on the pipeline component one and correspond to the two ends of the main throttle valve; the valve three and the valve four are both installed on the pipeline component two and correspond to the two ends of the slave throttle valve.

[0030] The beneficial effects of the above technical solution are: valve one and valve two can cut off the pipelines at both ends of the corresponding main throttle valve, so as to facilitate the repair and maintenance of the main throttle valve; valve three and valve four can cut off the pipelines at both ends of the slave throttle valve, so as to facilitate the repair and maintenance of the slave throttle valve.

[0031] As a further improvement of the above technical solution, a liquid-gas separator is also included; the pipeline component 1, the pipeline component 2 and the outlet of the sand discharge valve are all connected through pipelines and communicated with the liquid-gas separator.

[0032] The beneficial effects of the above technical solution are: liquid-gas separator; the mud output from the outlet of pipeline component 1, pipeline component 2 and sand discharge valve is collected into the liquid-gas separator through the pipeline for liquid-gas separation.

[0033] Another aspect of the present invention provides a pressure control method for a dual-throttle synchronous fine pressure control system with an active sand discharge function, which includes the following pressure control modes:

[0034] Mode 1: When large-flow mud output and precise pressure control are required, the control system synchronously controls the main throttle pipeline assembly and the slave throttle pipeline assembly to regulate the flow and perform precise pressure control.

[0035] Mode 2: When a small flow rate is required to output mud and fine pressure control is required, the control system closes the slave throttling pipeline assembly and independently controls the master throttling pipeline assembly to regulate the flow rate and perform fine pressure control.

[0036] Mode 3: When it is necessary to discharge the impurities accumulated in the sand-containing cavity of the active sand discharge pipeline assembly, the sand discharge valve is controlled to open by the control system to flush the sand-containing cavity with the help of mud flow to discharge the sand.

[0037] As a further improvement to the above technical solution, in mode 1, dual-valve synchronous control under large flow rate includes the following steps:

[0038] Step 1: Establish a master valve controller to control the master throttle valve, and establish a slave valve controller to control the slave throttle valve;

[0039] Step 2: In each sampling period, measure the current pressure of the master throttle valve and the slave throttle valve;

[0040] Step 3: The main valve controller calculates the optimal control signal based on the master-slave following strategy and the current state and applies it to the main throttle valve;

[0041] Step 4: Calculate the target pressure of the slave throttle valve based on the master throttle valve pressure and the set following relationship;

[0042] Step 5: The slave valve controller calculates the control signal according to the master-slave following strategy and acts on the slave throttle valve.

[0043] It can be seen from the above technical solution that, compared with the prior art, the present invention discloses a dual-throttling synchronous fine pressure control system and method with active sand discharge function, which has the following advantages and beneficial effects:

[0044] 1. The present invention effectively avoids blockage of the throttling channel, reduces equipment maintenance and downtime, and improves the efficiency of drilling operations.

[0045] 2. The present invention effectively solves the problem of fine pressure control capability of a manifold under full-range flow, improves the adaptability of the equipment and its adaptability to complex drilling conditions, saves supporting costs, and reduces well control risks.

[0046] 3. The present invention significantly improves the stability of bottom hole pressure control, ensuring the safety of drilling operations under complex geological conditions.

[0047] 4. The present invention reduces the need for manual intervention and alleviates the workload of operators.

[0048] 5. The present invention effectively solves the pressure control problem under the full range of flow rates, from extremely small flow rates to extremely large flow rates, avoids pressure fluctuations caused by blockage by large-particle cuttings, improves the stability and reliability of bottom hole pressure control, reduces equipment maintenance and downtime, and significantly improves drilling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0050] Figure 1 A three-dimensional schematic diagram of the overall structure of a dual-throttling synchronous fine pressure control system with active sand discharge function according to the present invention;

[0051] Figure 2 A schematic structural diagram of an active sand removal pipeline assembly of a dual-throttling synchronous fine pressure control system with an active sand removal function according to the present invention;

[0052] Figure 3 A schematic structural diagram of a main throttling pipeline assembly of a dual-throttling synchronous fine pressure control system with an active sand discharge function according to the present invention;

[0053] Figure 4 A schematic structural diagram of a diversion filter of a dual-throttling synchronous fine pressure control system with an active sand removal function according to the present invention;

[0054] Figure 5 A flow chart of dual-valve master-slave synchronous throttling pressure control of a dual-throttling synchronous fine pressure control system with active sand discharge function according to the present invention;

[0055] In the figure: 1. Diverter filter; 11. Filter screen; 12. Inlet; 13. Outlet 1; 14. Outlet 2; 15. Outlet 3; 2. Active sand discharge pipeline assembly; 21. Impurity storage and weighing chamber; 211. Impurity storage chamber; 2111. Sand holding cavity; 212. Weighing unit; 22. Flexible pipeline 1; 23. Flexible pipeline 2; 24. Sand discharge valve; 3. Main throttling pipeline assembly; 31. Pipeline assembly 1; 32. Main throttling valve; 33. Valve 1; 34. Valve 2; 4. Slave throttling pipeline assembly; 41. Pipeline assembly 2; 42. Slave throttling valve; 43. Valve 3; 44. Valve 4; 5. Liquid-gas separator; 6. Blowout preventer. DETAILED DESCRIPTION

[0056] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0057] In the description of the present invention, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0058] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0059] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0060] According to an embodiment of the present invention, Figures 1 to 5 As shown, a dual-throttling synchronous fine pressure control system with active sand discharge function includes: a diverter filter 1, an active sand discharge pipeline assembly 2, a main throttling pipeline assembly 3, a slave throttling pipeline assembly 4 and a control system.

[0061] The diverter filter 1 has an inlet 12 that can be connected to the mud outlet of the blowout preventer 6; when in use, the inlet of the diverter filter 1 is connected to the mud outlet of the blowout preventer 6 (the blowout preventer 6 can be a rotary blowout preventer) through a pipeline (a main valve is installed on this pipeline); the diverter filter 1 has an outlet 13, an outlet 2 14 and an outlet 3 15, and filter screens 11 are installed on the diverter filter 1 corresponding to the outlet 2 and the outlet 3.

[0062] The active sand discharge pipeline assembly 2 has a sand cavity 2111, and the inlet of the sand cavity 2111 is connected to the outlet 1 of the diversion filter 1; a sand discharge valve 24 capable of opening and closing the outlet of the sand cavity 2111 is installed on the side of the active sand discharge pipeline assembly 2 corresponding to the outlet 1 of the sand cavity 2111.

[0063] The inlets of the main throttling pipeline assembly 3 and the secondary throttling pipeline assembly 4 are connected in a one-to-one correspondence through pipelines and communicate with the second outlet and the third outlet of the diverter filter 1 .

[0064] The control system is electrically connected to the sand discharge valve 24 to perform sand discharge control; the control system is electrically connected to the main throttling pipeline assembly 3 and the slave throttling pipeline assembly 4 to perform flow control and pressure control.

[0065] When the dual-throttling synchronous fine pressure control system with an active sand discharge function of this embodiment is used, when the sand discharge valve 24 is closed, the mud can be transported from the second and third outlets to the corresponding main throttling pipeline assembly 3 and the secondary throttling pipeline assembly 4 after entering the diversion filter 1. Since the filter screens 11 are installed at the second and third outlets, only small particles of rock chips and other impurities are allowed to enter the main throttling pipeline assembly 3 and the secondary throttling pipeline assembly 4. Large particles of rock chips and other impurities continuously enter the sand holding cavity 2111 of the active sand discharge pipeline assembly 2 under the impact of the mud flow and are temporarily stored in a centralized manner to avoid clogging the filter screen 11. When large particles of rock chips and other impurities accumulate in the sand holding cavity 2111 to a certain amount or for a certain period of time, the control system can automatically open the sand discharge valve 24 to allow the mud flow to directly flush the sand holding cavity 2111 to discharge the large particles of rock chips and other impurities accumulated therein, thereby effectively preventing the main throttling pipeline assembly 3 and the secondary throttling pipeline assembly 4 from being blocked, creating favorable conditions for fine pressure control. When a large amount of mud is required for drilling and fine pressure control during the operation, the operator needs to open two throttling branches, that is, open the main throttling pipeline assembly 3 and the slave throttling pipeline assembly 4, and perform dual throttling synchronous fine pressure control; through the dual throttling synchronous control method, it is possible to accurately achieve dual throttling synchronous fine pressure control under large flow, meeting the pressure control requirements of large mud displacement. When an extremely small flow circulation is required during the operation and a fine pressure control process needs to be performed, the control system will close the slave throttling pipeline assembly 4 and use the main throttling pipeline assembly 3 to achieve fine pressure control under extremely small mud flow. The present invention realizes effective removal of solid particles in the drilling fluid through the active sand removal pipeline assembly 2 for active sand removal and anti-blocking and the synchronous control of the dual throttling branches, and adapts to the fine pressure control of the maximum and minimum global flow rates, thereby improving the stability and reliability of bottom hole pressure control.

[0066] In some embodiments, the active sand discharge pipeline assembly 2 includes an impurity storage and weighing chamber 21, a flexible pipeline 1 22, and a flexible pipeline 2 23; the inner cavity of the impurity storage and weighing chamber 21 is a sand holding cavity 2111; the inlet of the sand holding cavity 2111 is connected and communicated with a port of the flexible pipeline 1 22, and the other port of the flexible pipeline 1 22 is connected and communicated with an outlet 1 of the diverter filter 1; the outlet of the sand holding cavity 2111 is connected and communicated with a port of the flexible pipeline 2 23; the other port of the flexible pipeline 2 23 is connected and communicated with the inlet of the sand discharge valve 24;

[0067] The control system is electrically connected to the impurity storage weighing chamber 21 to monitor the amount of impurities stored in the sand holding cavity 2111 .

[0068] The impurity storage weighing chamber 21 has the function of actively sensing the accumulation amount of impurities such as rock cuttings in the sand containing cavity 2111; when the impurities such as rock cuttings in the sand containing cavity 2111 accumulate to a certain preset weight, the control system can obtain the cumulative weight signal of the impurities such as rock cuttings, and then control the sand discharge valve 24 to open for automatic unblocking. After the sand discharge valve 24 is opened, the mud flow passes through the flexible pipeline 1 22, the sand containing cavity 2111, the flexible pipeline 2 23 and the sand discharge valve 24 in sequence to flush and discharge the impurities in the sand containing cavity 2111. After the impurities in the sand containing cavity 2111 are discharged, the sand discharge valve 24 is closed.

[0069] In some embodiments, the flexible pipeline 1 22 , the impurity storage and weighing chamber 21 , and the flexible pipeline 2 23 are sequentially connected along the length direction to form an active blockage-removing straight-through pipeline.

[0070] The purpose of constructing an active blockage-removing straight-through pipeline is to make the incoming flow more impactful and the flushing effect better.

[0071] In some embodiments, the impurity storage weighing chamber 21 includes an impurity storage chamber 211 and a weighing unit 212; the inner cavity of the impurity storage chamber 211 is a sand cavity 2111; the weighing unit 212 is connected to the impurity storage chamber 211 for weighing; the control system is electrically connected to the weighing unit 212 to collect and obtain the weight signal of the accumulated impurities in the sand cavity 2111 in real time.

[0072] Since the inlet and outlet of the sand-containing cavity 2111 of the impurity storage chamber 211 are connected one-to-one and connected to the flexible pipe 1 22 and the flexible pipe 2 23; the flexible pipe 1 22 and the flexible pipe 2 23 are flexible high-pressure hoses that can be retracted and deformed, so that the impurity storage chamber 211 can move up and down freely; that is, as the impurities in the sand-containing cavity 2111 increase, the impurity storage chamber 211 will move downward under the action of gravity, and then be sensed by the weighing unit 212, and the weighing unit 212 can monitor the accumulated amount of impurities in the sand-containing cavity 2111.

[0073] Specifically, the impurity storage chamber 211 is a straight tube, with a sand-containing cavity 2111 in the middle of its length direction, and two ports in the length direction serving as the inlet and outlet of the sand-containing cavity 2111; the two ports of the impurity storage chamber 211 are sealed and connected one by one through a flange structure and connect the flexible pipeline 1 22 and the flexible pipeline 2 23.

[0074] In some embodiments, the weighing unit 212 is a pressure-sensitive element; the pressure-sensitive element is installed at the lower end of the impurity storage chamber 211 to measure the gravity of the impurity storage chamber 211 in real time.

[0075] The weighing unit 212 is a pressure-sensitive element and is supported at the lower end of the impurity storage chamber 211. Its function is to directly weigh the weight of the impurity storage chamber 211, and then determine the accumulated amount of impurities in the sand cavity 2111 based on the weight difference.

[0076] In some embodiments, the diverter filter 1 is in a cubic shape, and the inlet and outlet 1 of the diverter filter 1 are respectively arranged on two opposite side walls of the diverter filter 1; outlet 2 and outlet 3 of the diverter filter 1 are respectively arranged on the other two opposite side walls of the diverter filter 1; the impurity storage chamber 211 is arranged along the liquid outlet direction of outlet 1 in the length direction, and the diverter filter 1, flexible pipeline 1 22, impurity storage chamber 211, flexible pipeline 2 23 and sand discharge valve 24 are sequentially connected along the length direction to form an active deblocking straight-through pipeline.

[0077] Specifically, the main throttle pipeline assembly 3 and the secondary throttle pipeline assembly 4 are arranged parallel and symmetrically on either side of the active sand removal pipeline assembly 2. The inlets of the main throttle pipeline assembly 3 and the secondary throttle pipeline assembly 4 are connected via pipelines in a one-to-one correspondence and communicate with outlets 2 and 3 of the diverter filter 1. Pressure sensors 7 are installed on the connecting pipelines between the inlets of the main throttle pipeline assembly 3 and the secondary throttle pipeline assembly 4 and the diverter filter 1 to monitor the fluid pressure in the pipeline upstream of the valve.

[0078] During the operation, large-particle cuttings in the drilling mud are continuously accumulated in the middle sand cavity 2111 and the active drainage straight-through pipeline of the pressure-sensitive element. The impurity storage chamber 211 will produce a vertical downward displacement due to gravity. The gravity directly acts on the high-precision pressure-sensitive element, which senses the gravity changes of the entire impurity storage chamber 211 in real time. When the rock cuttings accumulation reaches the threshold value (G t+Δt ≥(1+X%)G t , X represents the sand discharge threshold), triggering the automatic sand discharge program. The intelligent control system actively controls the sand discharge valve 24 of the active drainage straight-through pipeline to open, and the high-pressure mud fluid actively flushes and discharges the sand through the drainage channel, thereby discharging the large-particle rock debris accumulated in the sand-containing cavity 2111.

[0079] In some embodiments, the main throttle pipeline assembly 3 includes a pipeline assembly 1 31 and a main throttle valve 32; the slave throttle pipeline assembly 4 includes a pipeline assembly 2 41 and a slave throttle valve 42;

[0080] The inlet of the pipeline component 1 31 is connected to and communicates with the outlet 2 of the diverter filter 1; the main throttle valve 32 is installed on the pipeline component 1 31 for flow control;

[0081] The inlet of the second pipe assembly 41 is connected to and communicates with the outlet 3 of the diverter filter 1; a throttle valve 42 is installed on the second pipe assembly 41 to control the flow;

[0082] The control system electrically connects the master throttle valve 32 and the slave throttle valve 42 to control their opening degrees.

[0083] The control system can control the opening and closing status and opening size of the main throttle valve 32 and the slave throttle valve 42, and then perform dual-valve synchronous control under large flow, realize dual-valve master-slave synchronous throttling control under full-range flow, and close the slave throttle valve 42 to only control the main throttle valve 32 to achieve fine pressure control under extremely small mud flow.

[0084] In some embodiments, the main throttling pipeline assembly 3 further includes a valve 1 33 and a valve 2 34; the slave throttling pipeline assembly 4 further includes a valve 3 43 and a valve 4 44;

[0085] Valve 1 33 and valve 2 34 are both installed on pipeline component 1 31 and correspond to the two ends of the main throttle valve 32; valve 3 43 and valve 4 44 are both installed on pipeline component 2 41 and correspond to the two ends of the slave throttle valve 42.

[0086] Valve one 33 and valve two 34 can cut off the pipelines at both ends of the corresponding main throttle valve 32 to facilitate repair and maintenance of the main throttle valve 32; valve three 43 and valve four 44 can cut off the pipelines at both ends of the slave throttle valve 42 to facilitate repair and maintenance of the slave throttle valve 42.

[0087] Specifically, the main throttling pipeline assembly 3 and the slave throttling pipeline assembly 4 have the same structure.

[0088] In some embodiments, a liquid-gas separator 5 is further included; the outlets of the pipeline component 1 31 , the pipeline component 2 41 and the sand discharge valve 24 are all connected through pipelines and communicate with the liquid-gas separator 5 .

[0089] Liquid-gas separator 5; the mud output from the outlet of pipeline component 1 31, pipeline component 2 41 and sand discharge valve 24 are collected through the pipeline to the liquid-gas separator 5 for liquid-gas separation.

[0090] Specifically, before installing the dual-throttle, synchronized, fine pressure control system with active sand removal, each component undergoes rigorous quality inspection to ensure it is free of damage, deformation, and defects. First, the dual-throttle, synchronized, fine pressure control system with active sand removal is horizontally placed in the pre-set installation position and securely fastened with brackets and bolts to prevent displacement during operation. Figure 1 The dashed arrows in the middle indicate the sand discharge path.

[0091] Another aspect of the present invention provides a pressure control method for a dual-throttling synchronous fine pressure control system with an active sand discharge function, using a dual-throttling synchronous fine pressure control system with an active sand discharge function, including the following pressure control modes:

[0092] Mode 1: When a large flow rate of mud is required and fine pressure control is required, the control system synchronously controls the main throttling pipeline assembly 3 and the slave throttling pipeline assembly 4 to adjust the flow rate and perform fine pressure control;

[0093] Mode 2: When a small flow rate is required to output mud and fine pressure control is required, the control system closes the slave throttling pipeline assembly 4 and independently controls the master throttling pipeline assembly 3 to regulate the flow rate and perform fine pressure control.

[0094] Mode 3: When impurities accumulated in the sand containing cavity 2111 of the active sand discharge pipeline assembly 2 need to be discharged, the control system controls the sand discharge valve 24 to open, so as to flush the sand containing cavity 2111 with the help of mud flow to discharge sand.

[0095] In some embodiments, in mode 1, dual-valve synchronous control under high flow rate includes the following steps:

[0096] Step 1: Establish a master valve controller to control the master throttle valve 32 and establish a slave valve controller to control the slave throttle valve 42;

[0097] Step 2: In each sampling period, measure the current pressure of the master throttle valve 32 and the slave throttle valve 42;

[0098] Step 3: The main valve controller calculates the optimal control signal according to the master-slave following strategy and the current state and applies it to the main throttle valve 32;

[0099] Step 4: Calculate the target pressure of the slave throttle valve 42 based on the pressure of the master throttle valve 32 and the set following relationship;

[0100] Step 5: The slave valve controller calculates the control signal according to the master-slave following strategy and acts on the slave throttle valve 42 .

[0101] Specifically, when a large amount of mud is required for drilling and fine pressure control during the operation, the operator needs to open two throttling branches and use dual throttle valves (master throttle valve 32 and slave throttle valve 42) to synchronously perform fine pressure control. The two throttle valves of the two throttle branch manifolds are controlled by an intelligent control system to achieve dual-valve synchronous control under full flow and large flow, and realize dual-valve master-slave synchronous throttling control under full flow. The main throttle valve 32 is referred to as the master valve, and the slave throttle valve 42 is referred to as the slave valve. The method of dual-valve master-slave synchronous throttling pressure control is as follows:

[0102] ① Establish a main valve controller (based on model predictive control MPC)

[0103]

[0104] Among them, N p is the prediction time domain, N c is the control time domain, λ is the weight coefficient, P set is the pressure setting value, P A is the current pressure value of the main valve, u A is the main valve control signal, k is the current time point, and i is the time step.

[0105] ②Establish slave valve controller (based on master-slave following strategy)

[0106] P targetB =αP A +(1-α)P set

[0107] Among them, P targetB is the slave valve target pressure, and α is the following coefficient (0≤α≤1).

[0108] The control process is shown in the control flow chart. The dual throttle valve synchronous control method accurately realizes the precise synchronous pressure control of the dual throttle valves under large flow, meeting the pressure control requirements of large mud displacement.

[0109] When an extremely small flow circulation is required during the operation and a fine pressure control process needs to be performed, the control system will close the slave throttle valve 42 and use the main throttle valve 32 to achieve fine pressure control at an extremely small mud flow rate.

[0110] Through active sand removal through the straight-through pipeline and synchronous control of the dual throttle valves, active sensing and automatic blockage removal of solid particles in the drilling fluid are achieved, adapting to the precise pressure control of maximum and minimum global flow rates, and improving the stability and reliability of bottom hole pressure control.

[0111] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean 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 any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification.

[0112] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A dual-throttling synchronous fine pressure control system with active sand discharge function, characterized in that: include: A diverter filter (1), the diverter filter (1) having an inlet, an outlet 1, an outlet 2, and an outlet 3, and filter screens (11) are installed on the diverter filter (1) at locations corresponding to the outlet 2 and the outlet 3; An active sand discharge pipeline assembly (2), wherein the active sand discharge pipeline assembly (2) has a sand containing cavity (2111), the inlet of the sand containing cavity (2111) being connected to outlet 1 of the diversion filter (1); a sand discharge valve (24) capable of opening and closing the outlet of the sand containing cavity (2111) is installed on one side of the active sand discharge pipeline assembly (2) corresponding to outlet 1 of the sand containing cavity (2111); A main throttling pipeline assembly (3) and a secondary throttling pipeline assembly (4); the inlets of the main throttling pipeline assembly (3) and the secondary throttling pipeline assembly (4) are connected to the second outlet and the third outlet of the diverter filter (1) in a one-to-one correspondence; A control system is provided, wherein the control system is electrically connected to the sand discharge valve (24) to perform sand discharge control; the control system is electrically connected to the main throttling pipeline assembly (3) and the slave throttling pipeline assembly (4) to perform flow control and pressure control.

2. According to claim 1, a dual-throttling synchronous fine pressure control system with active sand discharge function is characterized in that: The active sand discharge pipeline assembly (2) comprises an impurity storage and weighing chamber (21), a flexible pipeline 1 (22) and a flexible pipeline 2 (23); the inner cavity of the impurity storage and weighing chamber (21) is a sand holding cavity (2111); the inlet of the sand holding cavity (2111) is connected to and communicated with a port of the flexible pipeline 1 (22), and the other port of the flexible pipeline 1 (22) is connected to and communicated with an outlet 1 of the diversion filter (1); the outlet of the sand holding cavity (2111) is connected to and communicated with a port of the flexible pipeline 2 (23); the other port of the flexible pipeline 2 (23) is connected to and communicated with the inlet of the sand discharge valve (24); The control system is electrically connected to the impurity storage weighing chamber (21) to monitor the amount of impurities stored in the sand holding cavity (2111).

3. A dual-throttling synchronous fine pressure control system with active sand discharge function according to claim 2, characterized in that: The flexible pipeline 1 (22), the impurity storage weighing chamber (21) and the flexible pipeline 2 (23) are sequentially connected along the length direction to form an active blockage-removing straight-through pipeline.

4. A dual-throttling synchronous fine pressure control system with active sand discharge function according to claim 2, characterized in that: The impurity storage and weighing chamber (21) comprises an impurity storage chamber (211) and a weighing unit (212); the inner cavity of the impurity storage chamber (211) is a sand-containing cavity (2111); the weighing unit (212) is connected to the impurity storage chamber (211) for weighing; and the control system is electrically connected to the weighing unit (212) to collect and obtain in real time a weight signal of impurities accumulated in the sand-containing cavity (2111).

5. A dual-throttling synchronous fine pressure control system with active sand discharge function according to claim 4, characterized in that: The weighing unit (212) is a pressure-sensitive element; the pressure-sensitive element is installed at the lower end of the impurity storage chamber (211) to measure the gravity of the impurity storage chamber (211) in real time.

6. A dual-throttle synchronous fine pressure control system with active sand discharge function according to claim 2, characterized in that: The main throttle pipeline assembly (3) includes a pipeline assembly 1 (31) and a main throttle valve (32); the slave throttle pipeline assembly (4) includes a pipeline assembly 2 (41) and a slave throttle valve (42); The inlet of the pipeline component 1 (31) is connected to and communicates with the outlet 2 of the diverter filter (1); the main throttle valve (32) is installed on the pipeline component 1 (31) to control the flow rate; The inlet of the second pipeline component (41) is connected to and communicates with the outlet 3 of the diverter filter (1); the secondary throttle valve (42) is installed on the second pipeline component (41) to control the flow rate; The control system electrically connects the main throttle valve (32) and the slave throttle valve (42) to control their opening degrees.

7. A dual-throttling synchronous fine pressure control system with active sand discharge function according to claim 6, characterized in that: The main throttling pipeline assembly (3) further includes a valve 1 (33) and a valve 2 (34); the slave throttling pipeline assembly (4) further includes a valve 3 (43) and a valve 4 (44); The valve one (33) and the valve two (34) are both installed on the pipeline component one (31) and correspond to the two ends of the main throttle valve (32); the valve three (43) and the valve four (44) are both installed on the pipeline component two (41) and correspond to the two ends of the slave throttle valve (42).

8. A dual-throttle synchronous fine pressure control system with active sand discharge function according to claim 6, characterized in that: It also includes a liquid-gas separator (5); the outlets of the pipeline component 1 (31), the pipeline component 2 (41) and the sand discharge valve (24) are all connected through pipelines and communicate with the liquid-gas separator (5).

9. A pressure control method for a dual-throttling synchronous fine pressure control system with active sand discharge function, characterized in that: A dual-throttling synchronous fine pressure control system with an active sand discharge function as described in any one of claims 1 to 8 is used, including the following pressure control modes: Mode 1: When a large flow rate of mud is required and fine pressure control is required, the main throttling pipeline assembly (3) and the slave throttling pipeline assembly (4) are synchronously controlled by the control system to adjust the flow rate and perform fine pressure control; Mode 2: When a small flow rate is required to output mud and fine pressure control is required, the control system closes the slave throttling pipeline assembly (4) and controls the master throttling pipeline assembly (3) separately to regulate the flow rate and perform fine pressure control. Mode 3: When it is necessary to discharge the impurities accumulated in the sand holding cavity (2111) of the active sand discharge pipeline assembly (2), the control system controls the sand discharge valve (24) to open, so as to flush the sand holding cavity (2111) with the help of mud flow to discharge the sand.

10. A pressure control method for a dual-throttling synchronous fine pressure control system with an active sand discharge function according to claim 9, characterized in that: In mode 1, dual-valve synchronous control at high flow rates includes the following steps: Step 1: Establishing a master valve controller to control the master throttle valve (32), and establishing a slave valve controller to control the slave throttle valve (42); Step 2: In each sampling period, measure the current pressure of the master throttle valve (32) and the slave throttle valve (42); Step 3: The main valve controller calculates the optimal control signal according to the master-slave following strategy and the current state and acts on the main throttle valve (32); Step 4: Calculate the target pressure of the slave throttle valve (42) based on the pressure of the master throttle valve (32) and the set follow-up relationship; Step 5: The slave valve controller calculates the control signal according to the master-slave following strategy and acts on the slave throttle valve (42).

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