An intelligent control system for blowout preventers

Abstract

The present invention relates to the technical field of drilling equipment, and particularly to an intelligent control system for a blowout preventer, comprising: a monitoring module that monitors the pressure data, the well fluid return volume, and the real-time drilling depth at several monitoring positions near the wellhead, the position information of the sliding sleeve and the operating current data of the drive motor during a single opening and closing process; a calculation module and a control module that determine the pressure fluctuation state based on the pressure data, the real-time drilling depth, and the dynamic pressure threshold, determine the overflow fluctuation state based on the well fluid return volume to determine the ejection state and determine the treatment method for the blowout preventer, and determine the displacement of the sliding sleeve based on the position information, determine the operating state of the motor based on the operating current data, and judge whether the blowout preventer fails according to the comparison result between the displacement of the sliding sleeve and the preset displacement or the operating state of the motor; an execution module that performs opening and closing actions on the ball valve according to the treatment method; and a warning module that issues an alarm signal according to the fault judgment result; the present invention realizes the intelligent control of the blowout preventer.

Description

Technical Field

[0001] The present invention relates to the technical field of drilling equipment, and in particular to an intelligent control system for a blowout preventer. Background Art

[0002] A blowout preventer is a safety sealing wellhead device commonly used in oil fields to prevent blowouts. It is used to close the wellhead during operations such as well testing, workover, and completion, prevent blowout accidents from occurring, maintain the wellbore pressure balance, and provide a safe and reliable working environment for wellhead operations.

[0003] Traditional internal blowout preventers in top drives are divided into upper blowout preventers and lower blowout preventers. During long-term operation, they need to be frequently replaced, and problems such as damage and failure of the upper blowout preventer or lower blowout preventer are likely to occur, which can easily affect the progress of drilling operations and increase operating costs. Moreover, when the blowout preventer is damaged and fails, the risk of blowout will increase significantly during the period before replacement. Blowouts may trigger secondary disasters such as fires and explosions, pose a serious threat to the lives of personnel on the drilling platform, and cause huge pollution to the surrounding environment.

[0004] Therefore, there is an urgent need for an intelligent control system for a blowout preventer to monitor the working state of the blowout preventer in real time, issue early warnings in a timely manner, and ensure that workers can take corresponding measures, such as adjusting drilling parameters and preparing replacement parts in advance, before the blowout preventer completely fails, so as to reduce the risks caused by the failure of the blowout preventer. Summary of the Invention

[0005] For this purpose, the present invention provides an intelligent control system for a blowout preventer to overcome the problem of insufficient monitoring ability for the failure and damage of blowout preventers in the prior art.

[0006] To achieve the above object, the present invention provides an intelligent control system for a blowout preventer, including:

[0007] A monitoring module, which is used to monitor the pressure data at several monitoring positions near the wellhead at several monitoring time points, the well fluid return volume of the wellhead, and the real-time drilling depth of the drill string during the process of lowering the drill string, and is also used to monitor the position information of the sliding sleeve inside the blowout preventer and the operating current data of the drive motor during a single opening and closing process of the blowout preventer;

[0008] A calculation module, which is connected to the monitoring module and is used to determine the pressure fluctuation state according to the pressure data, the real-time drilling depth, and the dynamic pressure threshold, determine the overflow fluctuation state according to the well fluid return volume, and determine the jet state according to the pressure fluctuation state and the overflow fluctuation state;

[0009] A control module, which is connected to the computing module, is used to determine the treatment method for the blowout preventer according to the injection state, determine the sliding sleeve displacement according to the position information, determine the motor operation state according to the operating current data, and judge whether the blowout preventer fails according to the comparison result between the sliding sleeve displacement and the preset displacement or the motor operation state;

[0010] An execution module, which is connected to the control module, includes a drive motor, a hydraulic pump, an oil cylinder, a sliding sleeve, and left and right knobs, and is used to control the drive motor, the hydraulic pump, the oil cylinder, the sliding sleeve, and the left and right knobs according to the treatment method to make the ball valve perform opening and closing actions;

[0011] An early warning module, which is connected to the control module, issues an alarm signal according to the fault judgment result;

[0012] Wherein, the pressure fluctuation state is consistent fluctuation or differential fluctuation, the overflow fluctuation state includes stable fluctuation and sharp fluctuation, and the injection state is true injection state or false injection state;

[0013] The control module determines the corresponding pressure change amplitude according to the pressure data at a single monitoring position, and determines the pressure fluctuation state according to the pressure change amplitude and the dynamic pressure threshold;

[0014] The control module constructs a formation pressure dynamic model according to the historical drilling depth and historical pressure data, and determines the dynamic pressure threshold according to the formation pressure dynamic model and the real-time drilling depth;

[0015] The control module determines the pressure fluctuation state according to the number of positions where the pressure change amplitude exceeds the dynamic pressure threshold and the total number of monitoring positions, where,

[0016] If the difference between the number of positions and the total number of monitoring positions is less than or equal to the first threshold, the pressure fluctuation state is consistent fluctuation;

[0017] If the difference between the number of positions and the total number of monitoring positions is greater than the first threshold, the pressure fluctuation state is differential fluctuation.

[0018] Further, the control module determines the well fluid return rate according to the well fluid return volume, and determines the overflow fluctuation state according to the comparison result between the well fluid return rate and the preset return rate, where,

[0019] If the well fluid return rate is less than the preset return rate, the overflow fluctuation state is stable fluctuation;

[0020] If the well fluid return rate is greater than or equal to the preset return rate, the overflow fluctuation state is sharp fluctuation.

[0021] Further, the control module determines the jetting state, where

[0022] if the pressure fluctuation state is consistent fluctuation and the overflow fluctuation state is sharp fluctuation, the jetting state is the true jetting state;

[0023] if the pressure fluctuation state is differential fluctuation and the overflow fluctuation state is stable fluctuation, the jetting state is the false jetting state.

[0024] Further, the control module determines the treatment method for the blowout preventer, where

[0025] if the jetting state is the true jetting state, the drive motor drives the ball valve in the blowout preventer to close itself at a preset speed;

[0026] if the jetting state is the false jetting state, the ball valve in the blowout preventer remains open.

[0027] Further, the control module determines whether the blowout preventer fails according to the slip displacement and the preset displacement, where

[0028] if the slip displacement is less than the preset displacement, the blowout preventer fails.

[0029] Further, the control module determines the starting point of current stability according to the operating current data during a single opening and closing process, and determines the operating state of the motor according to the change rate of the operating current after the starting point of current stability and the preset dynamic change rate.

[0030] Further, the control module determines the operating state of the motor based on the comparison result between the change rate of the operating current and the preset dynamic change rate, where

[0031] if the change rate of the operating current is lower than the preset dynamic change rate, the operating state of the motor is the stable operating state;

[0032] if the change rate of the operating current is greater than or equal to the preset dynamic change rate, the operating state of the motor is the abnormal fluctuation state.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows: according to the pressure data at several monitoring positions near the wellhead, the well fluid return volume at the wellhead, and the real-time drilling depth of the drill string at several monitoring time points during the process of lowering the drill string, the present invention judges the jetting state of the wellhead, accurately distinguishes between true jetting and false jetting, avoids shutting down the blowout preventer by mistake during false jetting, resulting in work stoppage for troubleshooting, and improves the overall operation efficiency. At the same time, precise fault diagnosis is carried out according to the position information of the slip and the operating current data of the drive motor during a single opening and closing process of the blowout preventer, the fault point is quickly located, the safety of the drilling operation is further improved, the sustainable progress of the drilling operation is ensured, and the intelligent control of the blowout preventer is realized.

[0034] Furthermore, the present invention determines the corresponding pressure change amplitude based on the pressure data at a single monitoring position, and determines the pressure fluctuation state based on the pressure change amplitude and the dynamic pressure threshold, which is convenient for further accurately distinguishing true spraying from false spraying, avoiding the shutdown for troubleshooting caused by mistakenly closing the blowout preventer during false spraying, improving the overall operation efficiency, further enhancing the safety of drilling operations, ensuring the sustainable progress of drilling operations, and realizing the intelligent control of the blowout preventer.

[0035] Furthermore, the present invention determines the well fluid return rate based on the well fluid return volume, determines the overflow fluctuation state based on the comparison result between the well fluid return rate and the preset return rate, and combines with the pressure fluctuation state to further accurately distinguish true spraying from false spraying, avoiding the shutdown for troubleshooting caused by mistakenly closing the blowout preventer during false spraying, improving the overall operation efficiency, further enhancing the safety of drilling operations, ensuring the sustainable progress of drilling operations, and realizing the intelligent control of the blowout preventer.

[0036] Furthermore, the present invention compares the sliding sleeve displacement with the preset displacement, determines the operating state of the sliding sleeve and the motor during the opening and closing of the ball valve based on the operating current data during a single opening and closing process, further conducts fault judgment, manually closes the blowout preventer, improves the overall operation efficiency, further enhances the safety of drilling operations, ensures the sustainable progress of drilling operations, and realizes the intelligent control of the blowout preventer. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic structural diagram of a blowout preventer applying the blowout preventer intelligent system according to an embodiment of the present invention;

[0038] Figure 2 is Figure 1 a schematic cross-sectional structure diagram of the valve body in

[0039] Figure 3 It is a connection block diagram of the blowout preventer intelligent control system according to an embodiment of the present invention;

[0040] Figure 4 It is a determination diagram for determining the spraying state according to an embodiment of the present invention;

[0041] In the figure: 1, valve body; 11, upper valve seat; 12, lower valve seat; 13, wave spring; 14, ball valve; 15, left and right knobs; 16, O-ring seal; 17, snap ring; 2, oil cylinder; 3, slide plate; 4, slider; 5, roller; 6, sliding sleeve; 7, knob wrench. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0042] In order to make the objectives and advantages of the present invention clearer and more understandable, the present invention will be further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0043] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and do not limit the protection scope of the present invention.

[0044] It should be noted that in the description of the present invention, the terms indicating directions or positional relationships such as "upper", "lower", "left", "right", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings. This is only for convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of the present invention.

[0045] In addition, it should also be noted that in the description of the present invention, unless otherwise clearly specified and defined, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0046] Please refer to Figure 1 、 Figure 2 as shown in Figure 1 is a schematic structural diagram of a blowout preventer applying the blowout preventer intelligent system according to an embodiment of the present invention. The blowout preventer can adopt two control modes: automatic control and manual control. The blowout preventer includes: a valve body 1, an oil cylinder 2, a slide plate 3, a slider 4, a roller 5, a sliding sleeve 6, and a knob wrench 7. Figure 2 is Figure 1 a schematic cross-sectional view of the structure of the valve body 1 in . The valve body 1 includes an upper valve seat 11 and a lower valve seat 12. A corrugated spring 13 is installed on the upper valve seat 11. Holes are symmetrically arranged on the outer surface of the valve body 1 for installing left and right knobs 15, and an O-ring 16 is used for sealing inside. Among them, the opening and closing state of the internal ball valve 14 is controlled by the left and right knobs 15. Under the control of the automation program system, the motor rotates to drive the hydraulic pump to move the oil cylinder 2 up and down. The oil cylinder 2 drives the sliding sleeve 6 to move up and down, and the hexagon inside the plug drives the left and right knobs 15 of the blowout preventer to control the opening and closing state of the blowout preventer.

[0047] Figure 3 is a connection block diagram of the blowout preventer intelligent control system according to an embodiment of the present invention. Specifically, the present invention provides a blowout preventer intelligent control system, including:

[0048] A monitoring module, which is used to monitor the pressure data at several monitoring positions near the wellhead at several monitoring time points during the process of lowering the drill string, the well fluid return volume of the wellhead, and the real-time drilling depth of the drill string, and is also used to monitor the position information of the sliding sleeve 6 in the blowout preventer and the operating current data of the drive motor during a single opening and closing process of the blowout preventer;

[0049] A calculation module, which is connected to the monitoring module, and is used to determine the pressure fluctuation state according to the pressure data, the real-time drilling depth, and the dynamic pressure threshold, determine the overflow fluctuation state according to the well fluid return volume, and determine the jet state according to the pressure fluctuation state and the overflow fluctuation state;

[0050] A control module, which is connected to the calculation module, and is used to determine the treatment method for the blowout preventer according to the jet state, determine the sliding sleeve displacement according to the position information, determine the motor operation state according to the operating current data, and judge whether the blowout preventer fails according to the comparison result between the sliding sleeve displacement and the preset displacement or the motor operation state;

[0051] An execution module, which is connected to the control module, includes a drive motor, a hydraulic pump, an oil cylinder, a sliding sleeve, and left and right knobs, and is used to control the drive motor, the hydraulic pump, the oil cylinder, the sliding sleeve, and the left and right knobs according to the treatment method to make the ball valve perform opening and closing actions;

[0052] An early warning module, which is connected to the control module, and issues an alarm signal according to the fault judgment result;

[0053] Wherein, the pressure fluctuation state is consistent fluctuation or differential fluctuation, the overflow fluctuation state includes stable fluctuation and sharp fluctuation, and the jet state is true jet state or false jet state.

[0054] It can be understood that in drilling operations, a blowout is an extremely dangerous accident that may cause catastrophic consequences such as casualties, environmental pollution, and equipment damage. Therefore, through the intelligent monitoring system of the blowout preventer, comprehensive monitoring is carried out to detect the blowout risk in the first time, automatically control the action of the blowout preventer, and reduce the probability of blowout. Blowout phenomena include true blowout and false blowout. True blowout refers to the phenomenon that the formation pressure in the wellbore is out of balance, and formation fluids (such as oil, natural gas, formation water, etc.) break through the pressure barrier of the drilling fluid under the drive of strong pressure and quickly rush from the bottom of the well to the wellhead along the wellbore. False blowout is usually a blowout-like phenomenon caused by non-formation pressure out-of-control factors such as equipment failures, abnormal drilling parameters, or external interferences.

[0055] When a similar blowout phenomenon occurs, it is necessary to make a distinction to avoid accidents. For example, when treating a false blowout as a real blowout, the blowout preventer will open and close frequently, delaying the construction period and accelerating the wear of the mechanical components and seals of the blowout preventer, shortening the service life of the equipment. On the contrary, if a real blowout is regarded as a false blowout and no effective well sealing measures are taken after the blowout occurs, the formation fluid will gush out of the wellhead uncontrollably in large quantities, bringing a high-pressure impact instantly, easily causing the collapse of the drilling platform and casualties, resulting in economic losses.

[0056] It can be understood that by monitoring the pressure data near the wellhead, the well fluid return volume, and combining with the real-time drilling depth of the drill string, it is possible to judge whether the jet state is a real blowout state or a false blowout state, and at the same time, the control system is processed correspondingly according to the jet state, including opening and closing the blowout preventer. Furthermore, since the opening and closing of the ball valve 14 are affected by the motor drive and the movement of the sliding sleeve 6, the position information of the sliding sleeve 6 and the operating current data of the drive motor are monitored during a single opening and closing process to help better judge the fault state of the blowout preventer, and the blowout preventer is manually closed by the staff in time to prevent further losses.

[0057] In a specific embodiment, the monitoring module includes a pressure sensor for monitoring the pressure data at several monitoring positions near the wellhead at several monitoring time points during the process of lowering the drill string, a flow sensor for monitoring the well fluid return volume at the wellhead, a depth sensor for monitoring the real-time drilling depth of the drill string, a displacement sensor for monitoring the position information of the sliding sleeve 6 during a single opening and closing process of the blowout preventer, and a current sensor for monitoring the operating current data of the drive motor. The several monitoring positions can be pressure sensors arranged at intervals of 20 cm under the same cross-section of the wellbore 0.5 m below the wellhead; the time interval of the several monitoring time points ranges from 1 min to 3 min, and preferably, the time interval of the several monitoring time points is 2 min; in practice, the range of values and the preferred values of the time interval of the several monitoring positions and the several monitoring time points can be determined according to the actual situation, which is not specifically limited here and will not be elaborated further.

[0058] In another specific embodiment, in addition to judging faults based on the displacement of the sliding sleeve and the operating state of the drive motor, it is also possible to monitor multiple parameters such as the pressure of the hydraulic pump and the working state of each sensor in the monitoring module, establish a comprehensive fault diagnosis model, and comprehensively analyze these parameters to improve the accuracy and reliability of fault judgment.

[0059] The present invention determines the wellhead jetting state based on the pressure data at several monitoring positions near the wellhead at several monitoring time points during the process of lowering the drill string, the well fluid return volume at the wellhead, and the real-time drilling depth of the drill string, accurately differentiates true jetting from false jetting, avoids shutting down the blowout preventer by mistake during false jetting, resulting in work stoppage for troubleshooting, and improves the overall operation efficiency. At the same time, precise fault diagnosis is carried out according to the position information of the sliding sleeve 6 and the operating current data of the drive motor during the single opening and closing process of the blowout preventer, quickly locates the fault point, further improves the safety of the drilling operation, ensures the sustainable progress of the drilling operation, and realizes the intelligent control of the blowout preventer.

[0060] Please refer to Figure 4 As shown, it is a determination diagram for determining the jetting state in an embodiment of the present invention. Specifically, the control module determines the corresponding pressure change amplitude based on the pressure data at a single monitoring position, and determines the pressure fluctuation state according to the pressure change amplitude and the dynamic pressure threshold.

[0061] Specifically, the control module constructs a formation pressure dynamic model based on the historical drilling depth and historical pressure data, and determines the dynamic pressure threshold according to the formation pressure dynamic model and the real-time drilling depth.

[0062] It can be understood that when there is true jetting, the root cause is the imbalance of the downhole formation pressure, and the pressure will rise rapidly and continue to increase. While in the case of false jetting, the pressure change amplitude is small, the fluctuation is irregular and shows differences. Therefore, the wellhead pressure data is monitored at several monitoring time points to determine the wellhead pressure fluctuation state, so as to facilitate the subsequent accurate judgment of the jetting state. The dynamic pressure threshold is a reference value for measuring the pressure change amplitude, and is used to judge whether the pressure change amplitude between adjacent monitoring time points reaches the true jetting state.

[0063] In a specific embodiment, at a single monitoring position, the pressure change amplitude is the difference between the pressure data at adjacent detection time points. The control module constructs a formation pressure dynamic model based on the historical drilling depth and historical pressure data, and more complex algorithms such as polynomial regression and neural network can be selected for fitting to describe the relationship between pressure and depth as accurately as possible to construct the formation pressure dynamic model. This model can reflect the general law of the formation pressure changing with depth in the drilling area, and at the same time take into account the influence of local special formations; determine the dynamic pressure threshold according to the formation pressure dynamic model and the real-time drilling depth. Substitute the real-time drilling depth into the formation pressure dynamic model to determine the estimated wellhead pressure value. The value range of the dynamic pressure threshold is 5% - 15% of the estimated wellhead pressure value. Preferably, the value of the dynamic pressure threshold is 10% of the estimated wellhead pressure value.

[0064] Specifically, the control module determines the pressure fluctuation state according to the number of positions where the pressure change amplitude exceeds the dynamic pressure threshold and the total number of monitoring positions, where

[0065] If the difference between the number of said positions and the total number of said monitoring positions is less than or equal to the first threshold value, the pressure fluctuation state is consistent fluctuation;

[0066] If the difference between the number of said positions and the total number of said monitoring positions is greater than the first threshold value, the pressure fluctuation state is differential fluctuation.

[0067] It can be understood that the total number of said monitoring positions is the total number of several monitoring positions. Under the true spraying state, the pressure fluctuation amplitude is large, and the pressure fluctuation amplitudes of each monitoring position are approximately the same. While under the false spraying state, the pressure fluctuation amplitude is small, and there may be a situation where the slight leakage of the seal affects the nearby pressure, resulting in differential fluctuations in the pressure fluctuation amplitudes of each monitoring position. Therefore, by judging the pressure fluctuation state, it is further determined whether the spraying state is true spraying or false spraying.

[0068] In a specific embodiment, the value range of the first threshold value is 0 to 2. Preferably, the value of the first threshold value is 0. When the number of positions where the pressure change amplitude exceeds the dynamic pressure threshold value is the same as the total number of monitoring positions, it indicates that the pressure fluctuation amplitudes of each monitoring position are approximately the same, and the pressure fluctuation state is consistent fluctuation.

[0069] The present invention determines the corresponding pressure change amplitude according to the pressure data at a single monitoring position, and determines the pressure fluctuation state according to the pressure change amplitude and the dynamic pressure threshold value, which is convenient for further accurately distinguishing true spraying and false spraying, avoiding the shutdown for troubleshooting caused by mistakenly closing the blowout preventer during false spraying, and improving the overall operation efficiency. Further improve the safety of drilling operations, ensure the sustainable progress of drilling operations, and realize the intelligent control of the blowout preventer.

[0070] Specifically, the control module determines the well fluid return rate according to the well fluid return volume, and determines the overflow fluctuation state according to the comparison result between the well fluid return rate and the preset return rate, where,

[0071] If the well fluid return rate is less than the preset return rate, the overflow fluctuation state is stable fluctuation;

[0072] If the well fluid return rate is greater than or equal to the preset return rate, the overflow fluctuation state is sharp fluctuation.

[0073] It is understandable that the well fluid return rate is the ratio of the well fluid return volume at a single monitoring time point to the theoretical well fluid return volume. If the well fluid return rate is greater than or equal to the preset return rate, it means that a large amount of well fluid returns from the wellhead. This may be because, under the action of a strong pressure, a large amount of fluid in the formation surges into the wellbore and quickly returns to the wellhead, showing a sharp fluctuation. If the well fluid return rate is less than the preset return rate, it indicates that the pressure change at the wellhead is not obvious. This may be because there is no large amount of high-pressure fluid surging into the wellbore underground, or even if some fluid enters, its energy is not sufficient to cause an obvious change in the wellhead pressure, which is defined as a stable fluctuation.

[0074] In a specific embodiment, the well fluid return rate is the ratio of the difference in well fluid return volume between adjacent monitoring time points to the well fluid return volume at the previous monitoring time point among the two monitoring time points. The value range of the preset return rate is ±1% to ±20%. Preferably, the value of the preset return rate is ±15%. In practice, the value range and preferred value of the preset return rate can be determined according to the actual situation, and no specific limitation is made here, nor will it be elaborated further.

[0075] Specifically, the control module determines the jetting state, where,

[0076] If the pressure fluctuation state is a consistent fluctuation and the overflow fluctuation state is a sharp fluctuation, then the jetting state is a true jetting state;

[0077] If the pressure fluctuation state is a differential fluctuation and the overflow fluctuation state is a stable fluctuation, then the jetting state is a false jetting state.

[0078] It is understandable that if the well fluid return volume increases sharply synchronously, the return rate rises, and the pressure fluctuation near the wellhead tends to be consistent, it is judged as a true jetting state. If the pressure fluctuation is small and the well fluid return volume is basically stable or only slightly changes, it is judged as a false jetting state.

[0079] Specifically, the control module determines the treatment method for the blowout preventer, where,

[0080] If the jetting state is a true jetting state, the drive motor drives the ball valve 14 in the blowout preventer to close at a preset speed;

[0081] If the jetting state is a false jetting state, the ball valve 14 in the blowout preventer remains open.

[0082] It can be understood that the control module can quickly respond at the moment when signs of real blowout are detected (such as a sharp rise in wellhead pressure, a sharp increase in the return volume of well fluid, etc.), start components such as the motor and hydraulic pump, control the rotation of the motor to drive the hydraulic pump and the cylinder to move, the cylinder drives the sliding sleeve 6 to move, and the hexagon inside the plug drives the blowout preventer knob to rotate to close the ball valve 14 and close the blowout preventer. If a false blowout is detected, the ball valve 14 of the blowout preventer can be kept open, and continuous monitoring can be continued.

[0083] The present invention determines the well fluid return rate according to the well fluid return volume, determines the overflow fluctuation state according to the comparison result between the well fluid return rate and the preset return rate, and combines the pressure fluctuation state to further accurately distinguish real blowout from false blowout, avoiding shutdown and troubleshooting due to misclosing the blowout preventer during false blowout, improving the overall operation efficiency. Further improve the safety of drilling operations, ensure the sustainable progress of drilling operations, and achieve intelligent control of the blowout preventer.

[0084] Specifically, the control module determines whether the blowout preventer fails according to the displacement of the sliding sleeve and the preset displacement, where

[0085] if the displacement of the sliding sleeve is less than the preset displacement, the blowout preventer fails.

[0086] In a specific embodiment, the rotation of the motor drives the hydraulic pump, and the hydraulic pump drives the cylinder sliding sleeve 6 to move up and down. During the process of the ball valve 14 opening to closing, the sliding sleeve 6 will move up and down. Therefore, the preset displacement is defined as the moving distance of the sliding sleeve 6 from the starting position to the ending position during the process of the ball valve 14 opening to closing. If the displacement of the sliding sleeve is less than the preset displacement, it indicates that in the series of mechanical transmission processes from the motor to the hydraulic pump and then from the hydraulic pump to the cylinder sliding sleeve 6, there are problems such as excessive friction between transmission components, loosening at the connection parts, or damage to components, resulting in power loss during transmission, affecting the normal moving distance of the sliding sleeve 6 and making it unable to reach the preset value. At this time, a warning signal can be sent through the warning module, and the staff can manually close the blowout preventer to avoid related losses.

[0087] Specifically, the control module determines the starting point of current stability according to the operating current data during a single opening and closing process, and determines the operating state of the motor according to the change rate of the operating current after the starting point of current stability and the preset dynamic change rate.

[0088] Specifically, the control module determines the operating state of the motor based on the comparison result between the change rate of the operating current and the preset dynamic change rate, where

[0089] If the rate of change of the operating current is lower than the preset dynamic change rate, the operating state of the motor is a stable operating state; if the rate of change of the operating current is greater than or equal to the preset dynamic change rate, the operating state of the motor is an abnormal fluctuation state, and the control module determines that the blowout preventer fails when the operating state of the motor is an abnormal fluctuation state.

[0090] It can be understood that when the motor starts normally and drives the hydraulic pump to operate, the operating current of the motor will quickly rise to a stable value. The time point when the motor rises to the stable current is defined as the starting point of current stability. After determining the starting point of current stability, focus on the change of the operating current after this starting point. By calculating the rate of change of the operating current and comparing it with the preset dynamic change rate, the operating state of the motor can be judged. If the rate of change of the operating current is lower than the preset dynamic change rate, it means that the operation of the driving motor is relatively stable, and at this time, the operating state of the motor is determined to be a stable operating state. On the contrary, if the rate of change of the operating current is greater than or equal to the preset dynamic change rate, it indicates that the blowout preventer is likely to fail because the unstable and abnormal fluctuations of the motor operation often reflect problems in aspects such as power transmission, mechanical cooperation, or electrical control of the entire system, and these problems may affect the normal control of the ball valve 14 opening and closing by the blowout preventer, thereby affecting its blowout prevention function. At this time, a warning signal can be sent through the warning module, and the staff can manually close the blowout preventer to avoid related losses.

[0091] In a specific embodiment, the rate of change of the operating current is the ratio of the difference between the operating current data at adjacent time points after the starting point of current stability to the operating current data at the previous time point during a single opening and closing process. The value range of the preset dynamic change rate is ±5% to ±10%. Preferably, the value of the preset dynamic change rate is ±8%. In practice, the value of the preset dynamic change rate can be determined according to the actual situation, and no specific limitation is made here, nor will it be elaborated further.

[0092] In another specific embodiment, in addition to judging faults based on the slip sleeve displacement and the operating current of the driving motor, parameters such as the hydraulic pressure of the hydraulic pump and the working state of each sensor can also be monitored. By combining multiple parameters to establish a fault diagnosis model and comprehensively analyzing these parameters, the accuracy and reliability of fault judgment can be improved. In practice, the method of judging the blowout preventer fault can be determined according to the actual situation, and no specific limitation is made here, nor will it be elaborated further.

[0093] The present invention compares the slip sleeve displacement with the preset displacement, determines the operating states of the slip sleeve 6 and the motor during the opening and closing of the ball valve 14 according to the operating current data during a single opening and closing process, further conducts fault judgment, manually closes the blowout preventer, improves the overall operation efficiency, further enhances the safety of drilling operations, ensures the sustainable progress of drilling operations, and realizes the intelligent control of the blowout preventer.

[0094] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easily understood by those skilled in the art that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of the present invention.

Claims

1. A blowout preventer intelligent control system, characterized in that: include: A monitoring module, which is used to monitor the pressure data of several monitoring positions near the wellhead at several monitoring time points, the return volume of well fluid at the wellhead and the real-time drilling depth of the drilling tool during the drilling process, and is also used to monitor the position information of the sliding sleeve in the blowout preventer and the operating current data of the drive motor during a single opening and closing process; a calculation module connected to the monitoring module, for determining a pressure fluctuation state according to the pressure data, the real-time drilling depth and a dynamic pressure threshold, determining an overflow fluctuation state according to the well fluid return amount, and determining an injection state according to the pressure fluctuation state and the overflow fluctuation state; a control module connected to the calculation module, for determining a processing method for the blowout preventer according to the injection state, determining a sleeve displacement according to the position information, determining a motor operation state according to the operating current data, and determining whether the blowout preventer fails according to a comparison result between the sleeve displacement and a preset displacement or the motor operation state; an execution module, which is connected to the control module and includes a drive motor, a hydraulic pump, a cylinder, a sleeve and left and right knobs, and is used to control the drive motor, the hydraulic pump, the cylinder, the sleeve and the left and right knobs according to the processing method so that the ball valve performs an opening and closing action; An early warning module, which is connected to the control module and sends out an alarm signal according to the fault judgment result; Wherein, the pressure fluctuation state is a consistent fluctuation or a differential fluctuation, the overflow fluctuation state includes a stable fluctuation and a sharp fluctuation, and the injection state is a true injection state or a false injection state; The control module determines the corresponding pressure variation amplitude according to the pressure data at a single monitoring position, and determines the pressure fluctuation state according to the pressure variation amplitude and a dynamic pressure threshold; The control module constructs a formation pressure dynamic model according to historical drilling depth and historical pressure data, and determines the dynamic pressure threshold according to the formation pressure dynamic model and real-time drilling depth; The control module determines the pressure fluctuation state according to the number of positions where the pressure change amplitude exceeds the dynamic pressure threshold and the total number of monitoring positions, wherein: If the difference between the number of positions and the total number of monitoring positions is less than or equal to a first threshold, the pressure fluctuation state is a consistent fluctuation; If the difference between the number of positions and the total number of monitored positions is greater than a first threshold, the pressure fluctuation state is a differential fluctuation.

2. The BOP intelligent control system according to claim 1, characterized in that: The control module determines the well fluid return rate according to the well fluid return amount, and determines the overflow fluctuation state according to the comparison result between the well fluid return rate and the preset return rate, wherein: If the well fluid return rate is less than the preset return rate, the overflow fluctuation state is a stable fluctuation; If the well fluid return rate is greater than or equal to the preset return rate, the overflow fluctuation state is a sharp fluctuation.

3. The BOP intelligent control system according to claim 2 is characterized in that: The control module determines an injection state, wherein: If the pressure fluctuation state is a consistent fluctuation, and the overflow fluctuation state is a sharp fluctuation, the injection state is a true injection state; If the pressure fluctuation state is a differential fluctuation, and the overflow fluctuation state is a stable fluctuation, the injection state is a false injection state.

4. The BOP intelligent control system according to claim 3 is characterized in that: The control module determines the treatment method for the blowout preventer, wherein: If the injection state is a true injection state, the driving motor drives the ball valve in the blowout preventer to close automatically at a preset speed; If the injection state is a false injection state, the ball valve in the blowout preventer is continuously opened.

5. The BOP intelligent control system according to claim 1, characterized in that: The control module determines whether the blowout preventer fails according to the displacement of the sleeve and the preset displacement, wherein: If the displacement of the sliding sleeve is less than the preset displacement, the blowout preventer fails.

6. The BOP intelligent control system according to claim 1, characterized in that: The control module determines the current stabilization starting point according to the operating current data in a single switching process, and determines the motor operation state according to the operating current change rate after the current stabilization starting point and a preset dynamic change rate.

7. The intelligent control system for blowout preventer according to claim 6, characterized in that: The control module determines the motor operation state based on the comparison result between the running current change rate and the preset dynamic change rate, wherein: If the running current change rate is lower than the preset dynamic change rate, the motor running state is a stable running state; If the running current change rate is greater than or equal to the preset dynamic change rate, the motor operation state is an abnormal fluctuation state.

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