Control method and system for a choke and kill manifold

Abstract

The application provides a control method and system of a throttling well killing manifold, the throttling well killing manifold is connected with a wellhead device, and comprises a rapid blowout channel and a common blowout channel which are arranged in parallel, and a throttle valve is installed on the common blowout channel; the control method comprises the following steps: real-time monitoring of wellhead casing pressure P a and standpipe pressure P1, and determining the pressure difference between the wellhead casing pressure and the standpipe pressure; when P a -P l <P z , the drilling operation is normal, and the throttling well killing manifold is not opened; when P z ≤P a -P1<aP z , the throttling well killing manifold is opened, and the opening degree of the throttle valve is dynamically adjusted according to a throttle valve opening degree processing model; when P a -P1≥aP z , or there is no drilling fluid to be recovered in the separator and the well is full of gas, the rapid blowout channel is opened, and blowout operation is implemented. In the process of implementing the blowout operation, the application adopts multi-channel control, and ensures the timeliness and safety of the blowout.

Description

Technical Field

[0001] This invention relates to the field of oil and gas well control technology, and more specifically, to a control method for a choke-kill manifold and a control system for a choke-kill manifold. Background Technology

[0002] As oil and gas field exploration and development aggressively expands into new areas, ultra-deep formations, and unconventional directions, driven by dual-carbon goals, stabilizing oil production and increasing gas production is an inevitable trend in energy development. Natural gas development will continue to intensify, leading to a rise in well control risks. In recent years, overflow incidents have shown an upward trend, making it imperative to improve well control emergency response capabilities. Overall, wells with high pressure, high production, high sulfur content, and ultra-deep formations pose the greatest well control risks, while shallow wells also present significant well control problems. Unconventional oil and gas factory operations have brought new well control challenges. Simultaneously, the number of high-pressure, high-yield, high-sulfur, ultra-deep wells is increasing, and geological and engineering conditions are becoming increasingly complex, further increasing the difficulty of drilling and completion techniques and well control risks. Currently, the main method for balancing and controlling drilling pressure is through choke and kill manifolds. When a well kicks and overflows, the gas gradually slides and rises to the wellhead within the wellbore. Due to various reasons, the shut-in time may be prolonged, causing the wellhead shut-in pressure (casing pressure) to increase. The release of this pressure, i.e., the discharge of the accumulated gas at the wellhead, requires the opening and closing of the choke valve in the surface choke manifold. By opening and closing the choke valve in the choke manifold, a certain amount of back pressure in the wellbore is controlled, maintaining the balance of the bottom hole pressure system and achieving the purpose of controlling the blowout.

[0003] The development of choke and kill manifold control technology has undergone nearly a century of continuous improvement, roughly progressing from single-stage choke valves to multi-stage choke valves, from manual control of choke valve opening to hydraulic automatic control and then to electro-hydraulic combined automatic control. With the development of computer technology and intelligent control technology in recent years, computer-controlled multi-stage choke valve control technology has been developed.

[0004] For example, patent document CN104035383A, published on September 10, 2014, entitled "A Wireless Remote Centralized Control System and Method for a Surface Blowout Preventer and Choke Manifold," describes a wireless remote centralized control system for a choke manifold. This fully automatic high-pressure choke manifold control system includes a choke manifold and an electrical control system. The choke manifold includes at least two channel manifolds and at least two radial manifolds, with the radial manifolds used to connect the multi-channel manifolds. The electrical control system includes a pressure sensor and an electric valve installed on the choke manifold, a communication adapter box, a power adapter box, a remote control box, and a remote operating console. The fully automatic high-pressure choke manifold control system supports four control modes: local manual, local electric, local infrared remote control, and remote touchscreen control. However, although this method can be controlled via a wireless remote control, it cannot implement intelligent control of the choke manifold. In case of emergencies during drilling operations, it is still necessary to control and adjust it through off-site personnel or the driller, limiting its intelligent application.

[0005] A patent document published on June 17, 2022, entitled "A Controlled Pressure Drilling Surface Throttling Control Manifold Device" (publication number CN216767326U), describes a controlled pressure drilling surface throttling control manifold device, including a PLC controller, an electrically controlled throttling valve, a gate valve, and a throttling manifold system. The electrically controlled throttling valve and the gate valve are respectively installed in the throttling manifold system. The throttling manifold system includes branch I, branch II, branch III, branch IV, and branch V. Branch I, branch II, and branch III are connected by a tee T6; branch IV is connected to branch II by a tee T7; and branch V is connected to branch III by a tee T5. However, although this automatic surface throttling control system has a simple structure and flexible installation, and can solve the problem of conventional controlled pressure drilling systems being difficult to apply in well site space-constrained scenarios such as mountain drilling and offshore drilling, it still cannot be widely used to solve well control problems in high-pressure, high-yield unconventional oil and gas wells. Summary of the Invention

[0006] The purpose of this invention is to address at least one of the aforementioned shortcomings of the prior art. For example, one objective of this invention is to provide a control method and system for a choke-kill manifold to achieve intelligent control of the choke-kill manifold.

[0007] To achieve the above objectives, the present invention provides a control method for a choke-kill manifold, wherein the choke-kill manifold is connected to a wellhead device, and the choke-kill manifold includes a first venting channel and a second venting channel arranged in parallel, and a choke valve is installed on the second venting channel; the control method includes: real-time monitoring of the wellhead casing pressure P. a Determine the pressure difference between the wellhead casing pressure and the riser pressure P1; a -P l <Pz Under normal drilling operations, the choke and kill manifold is not activated; in P z ≤P a -P1<aP z In this case, the choke kill manifold is opened, and the choke valve opening is dynamically adjusted according to the choke valve opening handling model; when P a -P1≥aP z When, or when there is no drilling fluid to recover in the separator and the well is full of gas, the first venting channel is opened to carry out venting operations; among which, P z denoted as differential pressure warning value, 'a' as differential pressure warning correction coefficient, the riser is a high-pressure manifold located on the derrick, the separator is connected to the choke-kill manifold and is used in conjunction with the choke-kill manifold.

[0008] In an exemplary embodiment of the control method for the choke-kill manifold of the present invention, the choke valve opening adjustment processing model can be as follows:

[0009] If P a(i+1) >P ai The throttle valve opening is d i+1 for:

[0010] If P a(i+1) ≤P ai The throttle valve opening is d i+1 for:

[0011] In the formula, i represents the nth adjustment of the throttle valve opening; P a(i+1) P represents the wellhead casing pressure during the (i+1)th adjustment, in MPa; ai d represents the wellhead casing pressure during the i-th adjustment, in MPa; i+1 d represents the throttle valve opening during the (i+1)th adjustment; i-1 d represents the throttle valve opening during the (i-1)th adjustment; i- t represents the throttle valve opening during the i-th adjustment; i+1 This represents the opening d during the (i+1)th adjustment. i+1 The duration of retention, s; t i Indicates the opening degree d during the i-th adjustment. i The holding time, s.

[0012] In an exemplary embodiment of the control method for the throttling and killing manifold of the present invention, a>1.

[0013] In an exemplary embodiment of the control method for the throttling and killing manifold of the present invention, the control method may adopt a multi-level control mode, including a first-level control mode, a second-level control mode and a third-level control mode. The first-level control mode adopts intelligent control, the second-level control mode adopts automatic control, and the third-level control mode adopts manual control.

[0014] In an exemplary embodiment of the control method for the throttling and killing manifold of the present invention, multiple second venting channels may be provided, and the multiple second venting channels are connected in parallel and serve as backups for each other.

[0015] In an exemplary embodiment of the control method for the choke-kill manifold of the present invention, opening the choke-kill manifold may include: opening a choke valve on a second venting channel to a specified opening degree, so that P a -P l <P z If the throttle valve on one of the second discharge channels fails or fails to reach the specified opening, then the throttle valves on the other second discharge channels will be opened to the specified opening to ensure that P... a -P l <P z If all the throttle valves in the second venting channels are fully open, the pressure differential continues to rise to the upper limit, and the pressure is maintained for more than the first predetermined time, then the first venting channel is opened to allow P to... a -P l <P z .

[0016] In an exemplary embodiment of the control method for the choke-kill manifold of the present invention, the control method may further include: when the choke-kill manifold is already in a blowout condition, and P a -P1≥aP z The differential pressure value was maintained for more than the first predetermined time, while the wellhead casing pressure P a If the high pressure is maintained, connect the kill manifold and forcefully inject drilling fluid into the wellbore to carry out the kill operation.

[0017] Another aspect of the present invention provides a control system for a choke-kill manifold, the choke-kill manifold being connected to a wellhead device, the choke-kill manifold including a first venting channel and a second venting channel arranged in parallel, the second venting channel being equipped with a choke valve; the control system is connected to the choke-kill manifold and includes a data acquisition unit and a control unit, wherein the data acquisition unit is connected to the wellhead device and the riser respectively, and is configured to acquire the pressure difference signal between the wellhead casing pressure and the riser pressure; the control unit is connected to the data acquisition unit, the first venting channel and the second venting channel respectively, and is configured to intelligently control the opening and closing of the first venting channel and the second venting channel, and dynamically adjust the opening degree of the choke valve.

[0018] In an exemplary embodiment of the control system for the choke-kill manifold of the present invention, the control unit may include a judgment module, a first control module, a second control module, and a third control module, wherein the judgment module is connected to the acquisition unit and is configured to compare the pressure difference P between the wellhead casing pressure and the riser pressure. a -P1 and P z and aP z The first control module is connected to the judgment module and is configured to display the comparison result as P. a -P l <P z When the first and second jet discharge channels are closed, the second control module is connected to the judgment module and configured to close when the comparison result is P. z ≤P a -P1<aP z At that time, the system controls the opening of one or more second discharge channels, or controls the opening of all second discharge channels and the first discharge channel, and dynamically adjusts the opening of the throttle valve; the third control module is connected to the judgment module and is configured to display a comparison result of P. z ≤P a -P1<aP z At that time, control the opening of the first discharge channel.

[0019] In an exemplary embodiment of the control system for the choke and kill manifold of the present invention, the control unit may further include a display module configured to display the valve status and choke valve opening on the first and second venting channels.

[0020] Compared with the prior art, the beneficial effects of the present invention include at least one of the following:

[0021] (1) The present invention implements a three-level control method to intelligently control the choke and kill manifold. In the event of a well control emergency, the opening of the choke valve is quickly adjusted based on the proportional linear relationship between the change in wellhead casing pressure per unit time and the change in opening, which is conducive to reducing wellhead casing pressure.

[0022] (2) The present invention employs multi-channel control in the process of realizing the spouting operation, which ensures the timeliness and safety of spouting. Attached Figure Description

[0023] The above and other objects and / or features of the present invention will become clearer from the following description taken in conjunction with the accompanying drawings, in which:

[0024] Figure 1 A schematic diagram of the choke kill manifold control system of an exemplary embodiment of the present invention is shown.

[0025] Figure 2 A flowchart illustrating the control method of the choke kill manifold according to an exemplary embodiment of the present invention is shown.

[0026] Figure 3 A schematic diagram of the intelligent control logic of the control method for the choke kill manifold according to an exemplary embodiment of the present invention is shown.

[0027] Figure 4 A diagram illustrating the choke-kill manifold control relationship of the choke-kill manifold control method according to an exemplary embodiment of the present invention is shown.

[0028] Figure 5 A schematic diagram of the choke-kill manifold control function of the choke-kill manifold control method according to an exemplary embodiment of the present invention is shown.

[0029] Explanation of reference numerals in the attached figures:

[0030] 1-Wellhead device, 2-8# hydraulic plate valve, 3-First plate valve, 4-Second plate valve, 5-First throttle valve, 6-Third plate valve, 7-Fourth plate valve, 8-Fifth plate valve, 9-Second throttle valve, 10-Sixth plate valve, 11-Seventh plate valve, 12-Eighth plate valve, 13-Ninth plate valve, 14-Tenth plate valve, 15-Eleventh plate valve, 16-Third throttle valve, 17-Twelfth plate valve, 18-Thirteenth plate valve, 19-Fourteenth plate valve, 20-5a# hydraulic plate valve, 21-11# hydraulic plate valve, 22-12# hydraulic plate valve. Detailed Implementation

[0031] The control method and system for choke kill manifolds of the present invention will be described in detail below with reference to exemplary embodiments.

[0032] It should be noted that terms such as "first," "second," and "third" are used merely for ease of description and distinction, and should not be construed as indicating or implying relative importance. For those skilled in the art, some terms in this document, such as "pressure," are equivalent to electrical pressure.

[0033] This invention provides a method for controlling the throttling and killing manifold.

[0034] In an exemplary embodiment of the control method for the choke-kill manifold of the present invention, the choke-kill manifold is connected to a wellhead device and includes a first venting channel (i.e., a rapid venting channel) and a second venting channel (i.e., a normal venting channel) arranged in parallel, wherein a choke valve is installed on the normal venting channel. The control method for the choke-kill manifold includes the following steps:

[0035] S1, Real-time monitoring of wellhead casing pressure P aDetermine the pressure difference between the wellhead casing pressure and the riser pressure, along with the riser pressure P1. The riser is located in the high-pressure manifold on the derrick. The medium inside the riser is pumped to the riser on the derrick via a mud pump through the surface manifold, and then transported into the wellbore by a hose. The riser is not connected to the wellhead equipment, but the pressure relationship of the medium inside it needs to be adjusted between the two.

[0036] S2, when P a -P l <P z During normal drilling operations, the choke and kill manifold is not activated; when P z ≤P a -P1<aP z When P is activated, the choke kill manifold is opened, and the choke valve opening is dynamically adjusted according to the choke valve opening handling model; when P a -P1≥aP z When there is no drilling fluid (i.e., mud) to be recovered in the separator and the well is full of gas, the rapid venting channel is opened to carry out the venting operation.

[0037] Among them, P z The differential pressure warning value is denoted as 'a', and 'a' is the differential pressure warning correction coefficient, where 'a' can be greater than 1. The liquid-gas separator is connected to the choke-kill manifold and is used in conjunction with it; it is not connected to the wellhead equipment.

[0038] In this embodiment, the throttle valve opening adjustment processing model can be as follows:

[0039] If P a(i+1) >P ai The throttle valve opening is d i+1 for:

[0040] If P a(i+1) ≤P ai The throttle valve opening is d i+1 for:

[0041] In the formula, i represents the nth adjustment of the throttle valve opening; P a(i+1) P represents the wellhead casing pressure during the (i+1)th adjustment, in MPa; ai d represents the wellhead casing pressure during the i-th adjustment, in MPa; i+1 d represents the throttle valve opening during the (i+1)th adjustment; i-1 d represents the throttle valve opening during the (i-1)th adjustment; i- t represents the throttle valve opening during the i-th adjustment; i+1 This represents the opening d during the (i+1)th adjustment. i+1 The duration of retention, s; t i Indicates the opening degree d during the i-th adjustment. iThe holding time, s.

[0042] In this embodiment, the above control method can adopt a multi-level control mode, including a first-level control mode, a second-level control mode, and a third-level control mode. The first-level control mode adopts intelligent control, the second-level control mode adopts automatic control, and the third-level control mode adopts manual control.

[0043] In this embodiment, multiple ordinary discharge channels can be provided, and these channels are connected in parallel and serve as backups for each other.

[0044] In this embodiment, opening the choke kill manifold may include: opening a choke valve on a normal blowout channel to a specified opening degree, so that P a -P l <P z If the throttle valve on one of the normal discharge channels fails or does not reach the specified opening, then the throttle valves on other normal discharge channels will be opened to the specified opening to ensure that P... a -P l <P z If all throttle valves in the normal release channels are fully open, the pressure differential continues to rise to the upper limit, and the pressure is maintained for more than the first predetermined time, then the rapid release channel is opened to allow P to... a -P l <P z .

[0045] In this embodiment, the control method may further include: when the choke kill manifold is already in a blowout condition, and P a -P1≥aP z The differential pressure value was maintained for more than the first predetermined time, while the wellhead casing pressure P a If the high pressure is maintained, connect the kill manifold and forcefully inject drilling fluid into the wellbore to carry out the kill operation.

[0046] When the wellhead casing pressure P a As the pressure gradually increases, in order to ensure well pressure balance, control well pressure, and prevent well control emergencies, this invention adjusts the choke valve opening in an exponential ratio to the change in wellhead casing pressure per unit time, thereby rapidly adjusting the choke valve opening and facilitating a reduction in wellhead casing pressure; when the wellhead casing pressure P... a As the pressure gradually decreases, in order to prevent abnormal increases in well pressure and well control hazards, the throttle valve opening is adjusted linearly according to the change in wellhead casing pressure per unit time and the change in opening, thereby achieving a slow adjustment of the throttle valve opening (here, "slow" refers to a proportional adjustment relative to an exponential ratio), which is beneficial for controlling the hazards caused by abnormal changes in well control conditions.

[0047] Another aspect of the present invention provides a control system for a throttling and kill manifold.

[0048] In an exemplary embodiment of the control system for the choke-kill manifold of the present invention, the choke-kill manifold is connected to a wellhead device and includes a rapid venting channel and a normal venting channel arranged in parallel. A choke valve is installed on the normal venting channel. The control system is connected to the choke-kill manifold and includes a data acquisition unit and a control unit.

[0049] The acquisition unit is connected to the wellhead device and the riser respectively, and is configured to acquire the pressure difference signal between the wellhead casing pressure and the riser pressure.

[0050] The control unit is connected to the acquisition unit, the rapid discharge channel, and the normal discharge channel respectively, and is configured to intelligently control the opening and closing of the rapid discharge channel and the normal discharge channel, as well as dynamically adjust the opening of the throttle valve.

[0051] In this embodiment, the control unit may include a judgment module, a first control module, a second control module, and a third control module.

[0052] The judgment module is connected to the acquisition unit and is configured to compare the pressure difference P between the wellhead casing pressure and the riser pressure. a -P1 and P z and aP z Calculate the size between them and output the comparison result.

[0053] The first control module is connected to the judgment module and is configured to display P as the comparison result. a -P l <P z At that time, control the rapid discharge channel and the normal discharge channel to close.

[0054] The second control module is connected to the judgment module and is configured to display P as the comparison result. z ≤P a -P1<aP z At any time, control the opening of one or more normal discharge channels, or control the opening of all normal discharge channels and rapid discharge channels, and dynamically adjust the opening of the throttle valve.

[0055] The third control module is connected to the judgment module and is configured to display P as the comparison result. z ≤P a -P1<aP z At that time, control the opening of the rapid discharge channel.

[0056] In this embodiment, the control unit may further include a display module, which is configured to display the valve status and throttle valve opening on the rapid release channel and the normal release channel.

[0057] To better understand the exemplary embodiments of the present invention described above, further explanation is provided below with reference to specific examples and accompanying drawings.

[0058] Example 1

[0059] like Figure 1 As shown, the choke-kill manifold is connected to the wellhead device 1, including an 8# hydraulic flat valve 2, and three parallel-connected ordinary venting channels: ordinary venting channel one, ordinary venting channel two, ordinary venting channel three, and a rapid venting channel. Ordinary venting channel one includes a first flat valve 3 (i.e., flat valve J2b), a second flat valve 4 (i.e., flat valve J2a), a first choke valve 5 (i.e., choke valve J1), and a third flat valve 6 (i.e., flat valve J5) connected in sequence; ordinary venting channel two includes an eighth flat valve 12 (i.e., flat valve J6a), an eleventh flat valve 15 (i.e., flat valve J11), a third choke valve 16 (i.e., choke valve J12), and a twelfth flat valve 17 (i.e., flat valve J13) connected in sequence; ordinary venting channel three includes a... The fourth plate valve 7 (i.e., plate valve J3a), the fifth plate valve 8 (i.e., plate valve J3b), the second throttle valve 9 (i.e., throttle valve J4), and the sixth plate valve 10 (i.e., plate valve J7) are connected in parallel with the thirteenth plate valve 18 (i.e., plate valve J10a) and the seventh plate valve 11 (i.e., plate valve J10b); the rapid release channel includes the eighth plate valve 12 (i.e., plate valve J6a), the ninth plate valve 13 (i.e., plate valve J6b), and the tenth plate valve 14 (i.e., plate valve J9) connected in sequence.

[0060] against Figure 1 The control method for the throttling and kill manifold in the well can be achieved through the following scheme.

[0061] Step 1: Real-time monitoring of wellhead casing pressure P a Determine the pressure difference between the wellhead casing pressure and the riser pressure P1.

[0062] Step 2: Based on the wellhead casing pressure P a and riser pressure P l The difference between the two is used to implement intelligent control technology for the throttling and killing manifold, thereby reducing the wellhead casing pressure P. a and riser pressure P l The difference between them remained at a normal level.

[0063] like Figure 2 As shown, the intelligent control technology for choke and kill manifolds may include the following situations.

[0064] (1) When P a -P l <P z At that time, drilling operations were normal, and the choke and kill manifold was not activated.

[0065] (2) When Pz ≤P a -P1<aP z At that time, the No. 8 hydraulic flat valve will automatically open, dynamically adjusting the opening of the throttle valve in the ordinary discharge channel one, that is, dynamically adjusting the opening of throttle valve J1. The adjustment rule is as follows:

[0066] ①Based on the wellhead casing pressure P a The value is adjusted so that the opening degree d of the throttle valve J1 is opened to d1, and the opening degree d1 is maintained for t1; if the wellhead casing pressure P a If the opening continues to increase, the opening of throttle valve J1 is adjusted to d2, and the opening d2 is maintained for t2; this process is repeated continuously. i Open to d i+1 Opening degree d i The retention time is t i Until the throttle valve J1 is fully open.

[0067] Among them, the throttle valve opening degree d i+1 The adjustment and processing model is shown in the figure.

[0068] i) If P a(i+1) >P ai The throttle valve opening is d i+1 for:

[0069] ii) If P a(i+1) ≤P ai The throttle valve opening is d i+1 for:

[0070] ② When the opening degree of throttle valve J1 is d i At that time, if the wellhead casing pressure P a Decrease, reach P a -P l <P z At that time, the pressure difference P z If the stabilization time is T, then adjust the opening of the throttle valve J1 to 50% to resume normal drilling operations.

[0071] If the throttle valve J1 in the first normal venting channel fails or does not reach the specified opening degree, then the second normal venting channel is opened, i.e., the flat valve J11 is opened. Then, following procedures ① and ②, the opening and closing degree of the throttle valve J12 is intelligently adjusted (it should be understood that the throttle valve in ① and ② refers to J11, not J1). Finally, flat valves J2a and J5 are closed, thereby controlling the decrease, increase, or stabilization of wellhead casing pressure and standpipe pressure. In actual operation, manual inspection and maintenance of the throttle valve J1 is required at this time.

[0072] If both throttle valves J1 and J12 in ordinary venting channels one and two fail, or if wellhead conditions do not allow control of these two valves, then open ordinary venting channel three, open plate valve J3b, adjust throttle valve J4, and open plate valves J7 and J10a (plate valve J10b). Then close plate valves J6a and J13 to control the decrease, increase, or stabilization of wellhead casing pressure and standpipe pressure. Similarly, in actual operation, manual inspection and maintenance of throttle valves J12 and J1 are required at this time.

[0073] If the throttle valves J1, J12, or J4 of ordinary blowout channels one, two, and three are fully open, and P a -P1 pressure continues to rise to aP z If the pressure holding time exceeds t', then open the rapid release channel, i.e., first open plate valve J9, then open plate valve J6b to achieve rapid release. In actual operation, plate valves J2a, J3b, and J11 are manually checked and closed according to the site conditions. This process is valve inspection and maintenance to ensure valve reliability during readjustment. When the wellhead casing pressure P... a Decrease, reach P z ≤P a -P1<aP z At that time, the pressure difference P z If the stabilization time is T2, then close plate valves J6b and J9, and then adjust throttle valve J1, J12, or J4 according to procedures ① and ②. When the wellhead casing pressure P... a Suddenly decreased, reaching P a -P l <P z At that time, the pressure difference P z If the stabilization time is T, first close the plate valves J6b and J9, then close the throttle valves J1, J12, J4, and the #8 hydraulic plate valve to resume normal drilling operations. When the production rate is high and the throttling effect is insufficient, use the throttle valve J4 as an oil nozzle to control the flow rate, and then control the wellhead pressure through the throttle valves J1 or J12.

[0074] (3) When P a -P1≥aP z At that time, i.e., P a -P1 suddenly rises to aP l If, at this time, there is no drilling fluid to recover in the separator and the well is full of gas, open the rapid venting channel. First, open plate valve J9, then open plate valve J6b. Then, depending on the site conditions, check and close plate valves J2a, J3b, and J11 respectively, performing venting operations only through the rapid venting channel. During the venting process, when the wellhead casing pressure P... a Decrease, reach Pz ≤p a -P1<aP z At that time, the pressure difference P z If the stabilization time is T2, then close plate valves Jb6 and Jb9, and then adjust throttle valve J1, throttle valve J12, or throttle valve J4 according to procedures ① and ② in item (2). When the wellhead casing pressure P a Suddenly decreased, reaching P a -P l <P z At that time, the pressure difference P z If the stabilization time is T, first close the flat plate valves Jb6 and Jb9, then close the throttle valves J1, J12, or J4 to resume normal drilling operations.

[0075] When the throttling manifold system is already in the venting phase, P a -P1≥aP z The differential pressure over time has exceeded T; the wellhead casing pressure P a If high pressure is maintained, the kill manifold must be connected quickly, and drilling fluid must be forcibly injected into the wellbore to carry out the kill operation. The kill manifold is... Figure 1 The pipelines connected to the 5a#, 11#, and 12# hydraulic flat valves constitute the control system. During well control operations, first open flat valve 5a#, then open flat valve 11#. In emergencies, flat valve 12# can be opened for well control.

[0076] Flat plate valves J2a, J2b, J3a, and J3b are interchangeable valves for emergency valve repairs. J8 is a process shut-off valve (valve J8 is...). Figure 1 The fourteenth flat plate valve (19) in the middle.

[0077] like Figure 3 As shown, the intelligent control logic inputs the differential pressure signal between the casing pressure and the standpipe pressure into the intelligent control system. After filtering out other interfering signals, the signal is transmitted to the control unit. The control unit adjusts the valves in the throttling and killing manifold according to different differential pressure states. Simultaneously, the analog signal collected by the valves passes through an isolation safety barrier (which reduces mutual interference between strong and weak currents and greatly protects the safety of weak current signals) and enters the PLC analog input module, where it is converted into a digital signal and transmitted to the PLC's memory. Then, based on the sensor's range and other actual conditions, the digital signal is converted into an actual value and fed back to the control module for further adjustment. Simultaneously, the signal is also fed back to the display module for display.

[0078] like Figure 4As shown, a throttling and kill manifold control method can adopt a multi-level control mode, which includes primary control, secondary control and tertiary control. The primary control mode adopts intelligent control, the secondary control mode adopts automatic control, and the tertiary control mode adopts manual control.

[0079] like Figure 5 As shown, the control methods for the choke and kill manifold include intelligent control, automatic control, and manual control. During drilling operations, an intelligent control model is initially used; when intelligent control fails, automatic control can be employed, including remote control, driller's automatic control, remote automatic control, on-site control cabinet control, and on-site valve button control; in the event of an emergency power outage at the well site, manual control can be used, i.e., manually operating the valve handwheel.

[0080] Automatic control methods include:

[0081] a) Remote control: The opening degree of the throttle valve and the on / off status of the flat valve are controlled by wireless transmission via the Internet of Things.

[0082] b) Driller control: Valves are controlled via the control panel buttons in the driller's control room.

[0083] c) Remote automatic control, which is controlled by a remote field panel connected via a wired connection.

[0084] d) Field control cabinet control: Valve control is performed via the panel or touch screen of the field control cabinet.

[0085] e) On-site valve button control.

[0086] Manual control refers to the control of throttle valves and flat valves through mechanical switching.

[0087] In summary, the beneficial effects of the present invention include at least one of the following:

[0088] (1) The present invention implements a three-level control method to intelligently control the choke and kill manifold. In the event of a well control emergency, the opening of the choke valve is quickly adjusted based on the proportional linear relationship between the change in wellhead casing pressure per unit time and the change in opening, which is conducive to reducing wellhead casing pressure.

[0089] (2) The present invention employs multi-channel control in the process of realizing the spouting operation, which ensures the timeliness and safety of spouting.

[0090] Although the present invention has been described above in conjunction with exemplary embodiments and accompanying drawings, those skilled in the art should understand that various modifications can be made to the above embodiments without departing from the spirit and scope of the claims.

Claims

1. A control method for a throttling and kill manifold, characterized in that, The choke kill manifold is used to connect to the wellhead device. The choke kill manifold includes a first venting channel and a second venting channel arranged in parallel. A choke valve is installed on the second venting channel. The control method includes: Real-time monitoring of wellhead casing pressure P a and riser pressure P 1. Determine the pressure difference between the wellhead casing pressure and the riser pressure; exist Under normal drilling conditions, the choke kill manifold is not activated. exist In this case, the choke kill manifold is opened, and the choke valve opening is dynamically adjusted according to the choke valve opening handling model; and exist In the event that there is no drilling fluid to be recovered in the separator and the well is full of gas, the first venting channel is opened to carry out the venting operation. in, P z This is the differential pressure warning value. a This is the differential pressure warning correction factor. a >1. The riser is a high-pressure manifold located on the derrick. The separator is connected to the choke-kill manifold and is used in conjunction with the choke-kill manifold. The throttle valve opening processing model is shown below: like The throttle valve opening is d i+1 for: , like The throttle valve opening is d i+1 for: , In the formula, i Indicates which adjustment of the throttle valve opening has been made; P a(i+1) Indicates the first i Wellhead casing pressure during +1 adjustment, MPa; P ai Indicates the first i Wellhead casing pressure during the second adjustment, MPa; d i+1 Indicates the first i Throttling valve opening during +1 adjustment; d i-1 Indicates the first i -Throttle valve opening during the first adjustment; d i- Indicates the first i Throttling valve opening during the next adjustment; t i+1 Indicates the first i +1 adjustment of opening d i+1 The duration of retention, in seconds; t i Indicates the first i The opening degree during the next adjustment d i The holding time, s.

2. The control method for the choke-kill manifold according to claim 1, characterized in that, The control method adopts a multi-level control approach, including a first-level control approach, a second-level control approach, and a third-level control approach. The first-level control approach adopts intelligent control, the second-level control approach adopts automatic control, and the third-level control approach adopts manual control.

3. The control method for the choke and kill manifold according to claim 1, characterized in that, Multiple second-stage discharge channels are provided, and these channels are connected in parallel and serve as backups for each other.

4. The control method for the choke and kill manifold according to claim 3, characterized in that, The throttling and kill manifold includes: Open the throttle valve on a second discharge channel to the specified opening degree, so that... ; If the throttle valve on one of the second discharge channels fails or does not reach the specified opening degree, then the throttle valve on another of the plurality of second discharge channels is opened to the specified opening degree, so that... ; If all the throttle valves in the second venting channels are fully open, the pressure differential continues to rise to the upper limit, and the pressure is maintained for more than a first predetermined time, then the first venting channel is opened to allow... .

5. The control method for the choke-kill manifold according to claim 4, characterized in that, The control method further includes: when the choke kill manifold is already in a blowout condition, and The differential pressure value was maintained for more than the first predetermined time, while the wellhead casing pressure... If the high pressure is maintained, connect the kill manifold and forcefully inject drilling fluid into the wellbore to carry out the kill operation.

6. A control system for a choke and kill manifold, characterized in that, The choke kill manifold is used to connect to the wellhead device. The choke kill manifold includes a first venting channel and a second venting channel arranged in parallel. A choke valve is installed on the second venting channel. The control system is connected to the choke and kill manifold and includes a data acquisition unit and a control unit, wherein, The acquisition unit is connected to the wellhead device and the riser respectively, and is configured to acquire the pressure difference signal between the wellhead casing pressure and the riser pressure. The control unit is connected to the acquisition unit, the first discharge channel and the second discharge channel respectively, and is configured to intelligently control the opening and closing of the first discharge channel and the second discharge channel, as well as dynamically adjust the opening of the throttle valve.

7. The control system for the choke and kill manifold according to claim 6, characterized in that, The control unit includes a judgment module, a first control module, a second control module, and a third control module. The judgment module is connected to the acquisition unit and is configured to compare the pressure difference between the wellhead casing pressure and the riser pressure. P a - P 1 and P z and aP z Determine the size between them and output the comparison result; The first control module is connected to the judgment module and is configured to display the comparison result as... At that time, the first and second jet discharge channels are closed. The second control module is connected to the judgment module and is configured to display the comparison result as... At the same time, control the opening of one or more second discharge channels, or control the opening of all second discharge channels and the first discharge channel, and dynamically adjust the opening of the throttle valve; The third control module is connected to the judgment module and is configured to display the comparison result as... At that time, control the opening of the first discharge channel.

8. The control system for the choke and kill manifold according to claim 7, characterized in that, The control unit also includes a display module configured to display the valve status and throttle valve opening on the first and second discharge channels.

Images