Automatic control system and method for emergency shutdown of injection head

Abstract

The present invention is an automatic control system and method for emergency shutdown of an injection head, wherein the automatic control system for emergency shutdown of the injection head includes a load sensor, a control loop and an acquisition control module. The load sensor can detect in real time the load pressure set on the load sensor after the resultant force exerted on the coiled tubing in the well is transmitted to the injection head. The acquisition control module can obtain the resultant force exerted on the coiled tubing according to the load pressure detected by the load sensor. When the resultant force is less than a preset minimum weight value, or greater than a preset maximum weight value, or the rate of change of the resultant force is greater than a preset maximum weight change rate, the acquisition control module can control the injection head pump to depressurize and stop, and control the injection head brake to brake after the injection head pump depressurizes and stops. The present invention can ensure that the injection head is stopped in time when the coiled tubing is stuck / blocked during the operation of the formation, so as to avoid the coiled tubing being damaged by over-tension / compression, and can effectively improve the safety and reliability of the injection head.

Description

Technical Field

[0001] The invention relates to the technical field of petroleum equipment, and in particular to an automatic control system and method for emergency shutdown of an injection head. Background Art

[0002] In the past decade, with the promotion and application of coiled tubing operation technology, the cost per ton of oil has been effectively reduced, the operation efficiency has been greatly improved, the equipment technology level and service guarantee capabilities have been greatly improved, and the coiled tubing operation technology has been extended in depth, realizing the professionalization and large-scale development of the group company's coiled tubing operation technology. The number of coiled tubing operation machines and practitioners in various oil fields have shown explosive growth. Coiled tubing construction has the characteristics of fewer operators and fast lifting and lowering speed, but it is usually operated under pressure, and the working conditions after the coiled tubing enters the well are also particularly complex. During the process of lifting and lowering the coiled tubing, the injection head will be subject to its own gravity, wellbore friction, well pressure, unpredictable sticking / resistance, and the lifting / lowering force applied by the injection head. The combined force is expressed as the positive load (also called pipe weight) or negative load (also called pipe light) of the injection head load table, and the pipe weight and pipe light may switch at any time. The operator judges the operating status of the coiled tubing by closely monitoring the load table. When the load changes abnormally, it is necessary to make correct judgments and reactions in time.

[0003] At present, the coiled tubing operation machines on the market all adopt the mechanism of pressure feedback speed regulation in the injection head drive. The injection head operation speed is roughly adjusted by remote control pressure regulation, and the driving force of the injection head motor is limited. This is a protective control mode for the coiled tubing. In the actual operation process, there is often an increase in the virtual adjustment. Some users even directly adjust the injection head pressure regulating valve to the maximum pressure state to simplify the control process, and directly control the injection head up / down speed through the injection head direction control handle. These two control methods have no problems in the normal operation of the coiled tubing. Once the coiled tubing encounters resistance / stuck, the load changes suddenly, and the increase in the virtual adjustment pressure will appear. If the operator does not judge and react in time, the coiled tubing will be over-compressed or over-pulled in the wellbore in a spiral pile. Finally, the driving force is transmitted back from the motor end to the pump end, and the injection head pump swash plate is forced to swing back to the middle position to stop the injection head operation. This long-distance pressure transmission reaction lag and the injection head encountering resistance / stuck and not unloading the pressure and being stopped may squeeze / break the coiled tubing, posing a great threat to the life of the coiled tubing.

[0004] In addition, there are many continuous pipe operation processes, and the construction time usually lasts for several hours or even days. Operators will inevitably become tired due to long-term operation or be distracted by other things. Even when they are focused, due to the uneven technical levels, the average reaction time of operators is also long, making it difficult to avoid many sudden, potentially serious or even catastrophic events that may occur.

[0005] Therefore, the inventor, relying on many years of experience and practice in related industries, proposes an automatic control system and method for emergency shutdown of an injection head to overcome the defects of the prior art. Summary of the invention

[0006] The purpose of the present invention is to provide an automatic control system and method for emergency shutdown of an injection head, which can ensure that the injection head is stopped in time when the coiled tubing is stuck or blocked during the operation of the coiled tubing in the formation, thereby avoiding damage to the coiled tubing due to over-tension or over-pressure, and effectively improving the safety and reliability of the injection head.

[0007] The above-mentioned purpose of the present invention can be achieved by adopting the following technical solutions:

[0008] The present invention provides an injection head emergency shutdown automatic control system, comprising:

[0009] The load sensor is used to be installed on the injection head, and can detect in real time the load pressure on the load sensor after the combined force of the coiled tubing in the well is transmitted to the injection head;

[0010] A control circuit, the control circuit is used to connect with the injection head brake;

[0011] The acquisition control module is electrically connected to the load sensor and the control circuit. The acquisition control module can obtain the resultant force on the coiled tubing according to the load pressure detected by the load sensor. When the resultant force is less than a preset minimum weight value, or greater than a preset maximum weight value, or the rate of change of the resultant force is greater than a preset maximum weight change rate, the acquisition control module can control the injection head pump to depressurize and stop, and control the injection head brake to brake after the injection head pump depressurizes and stops.

[0012] In a preferred embodiment of the present invention, the load sensor is a bidirectional load sensor and is arranged on the box pressure rod of the injection head.

[0013] In a preferred embodiment of the present invention, the injection head emergency shutdown automatic control system further comprises a speed acquisition device, which can be used to detect the running speed of the coiled tubing in real time, and the acquisition control module is electrically connected to the speed acquisition device.

[0014] In a preferred embodiment of the present invention, the acquisition control module controls the injection head pump to depressurize and stop only when the change rate of the resultant force is greater than the preset maximum weight change rate and the running speed of the coiled tubing detected by the speed acquisition device is greater than the preset minimum speed.

[0015] In a preferred embodiment of the present invention, the acquisition control module can control the injection head brake through the control loop only after the injection head pump stops after depressurization and the running speed detected by the speed acquisition device is zero.

[0016] In a preferred embodiment of the present invention, the speed acquisition device includes a speed encoder; the speed encoder is arranged on the passive sprocket of the injection head; or a friction wheel is arranged on the box body of the injection head, on the guide pressure box of the injection head, or on the roller for winding the continuous tube, the friction wheel can be pressed on the surface of the continuous tube, and the speed encoder is arranged on the friction wheel.

[0017] In a preferred embodiment of the present invention, the injection head emergency shutdown automatic control system also includes a timer, and the acquisition control module is electrically connected to the timer. The injection head brake can be controlled through the control loop only after the injection head pump is depressurized and stopped, and the timer has counted for a preset time.

[0018] In a preferred embodiment of the present invention, the control circuit is also used to connect with the injection head pump and the drum brake, the injection head pump is a hydraulically controlled proportional pump, and the control circuit includes a hydraulic oil main pipeline, a first hydraulic pipeline, a second hydraulic pipeline and a third hydraulic pipeline; on the first hydraulic pipeline, an injection head manual brake control valve and an injection head brake control solenoid valve are provided in sequence from the first end to the second end, on the second hydraulic pipeline, a drum manual brake control valve is provided, and on the third hydraulic pipeline, a hydraulically controlled reversing valve, an injection head displacement control solenoid valve and a hydraulically controlled proportional direction control handle are provided in sequence from the first end to the second end; the first end of the first hydraulic pipeline is connected to the outlet end of the hydraulic oil main pipeline, and the second end of the first hydraulic pipeline is used to connect with the injection head manual brake control valve and the drum manual brake control solenoid valve; The first end of the second hydraulic pipeline is connected to the outlet end of the hydraulic oil main pipeline, and the second end of the second hydraulic pipeline is used to connect to the drum brake; the first end of the third hydraulic pipeline is connected to the hydraulic oil main pipeline, and the control oil port of the hydraulically controlled reversing valve is connected to the second hydraulic pipeline through the corresponding pipeline, and the connection point is located between the drum manual brake control valve and the second end of the second hydraulic pipeline, and the two output ports of the hydraulically controlled proportional direction control handle are respectively connected to the two hydraulic proportional control ports of the injection head pump; the acquisition control module can control the injection head displacement control solenoid valve to be energized so that the injection head pump can relieve pressure and stop rotating; and can control the injection head brake control solenoid valve to be energized so that the injection head brake can be braked.

[0019] In a preferred embodiment of the present invention, the injection head brake control solenoid valve and the injection head displacement control solenoid valve are both two-position three-way solenoid valves, and both have an oil inlet, a working port and an oil return port, and when the two-position three-way solenoid valve is in a de-energized state, the oil inlet is connected to the working port, and when the two-position three-way solenoid valve is in a energized state, the working port is connected to the oil return port.

[0020] In a preferred embodiment of the present invention, a first pressure reducing valve is provided on the hydraulic oil main pipeline and between the first end of the third hydraulic pipeline and the outlet end of the hydraulic oil main pipeline, and a second pressure reducing valve and a third pressure reducing valve are provided in sequence on the third hydraulic pipeline and between the first end thereof and the hydraulically controlled proportional directional control handle; a shuttle valve is connected in parallel to the hydraulically controlled proportional directional control handle or a shuttle valve is integrated in the hydraulically controlled proportional directional control handle, the two inlets of the shuttle valve are respectively connected to the two output ports of the hydraulically controlled proportional directional control handle, and the outlet of the shuttle valve is connected to a pressure gauge.

[0021] In a preferred embodiment of the present invention, the injection head emergency shutdown automatic control system also includes an electric proportional direction control handle and a potentiometer electrically connected to the acquisition control module, and the acquisition control module is also used to be electrically connected to the injection head pump, and the injection head pump is an electric proportional closed pump; the control circuit includes a hydraulic oil main pipeline and a first hydraulic pipeline, and an injection head brake control solenoid valve is provided on the first hydraulic pipeline, the first end of the first hydraulic pipeline is connected to the outlet end of the hydraulic oil main pipeline, and the second end of the first hydraulic pipeline is used to connect to the injection head brake; the acquisition control module can relieve pressure and stop the injection head pump by resetting the electrical signal of the injection head pump to zero; and can brake the injection head brake by controlling the injection head brake control solenoid valve to lose power.

[0022] In a preferred embodiment of the present invention, the control circuit also includes a second hydraulic pipeline, on which a roller brake control solenoid valve is provided, the first end of the second hydraulic pipeline is connected to the outlet end of the hydraulic oil main pipeline, and the second end of the second hydraulic pipeline is used to connect to the roller brake; after the roller brake control solenoid valve is in the energized position, the acquisition control module can control the injection head pump to obtain an electrical signal.

[0023] In a preferred embodiment of the present invention, the injection head brake control solenoid valve and the roller brake control solenoid valve are both two-position three-way valves, and both have an oil inlet, a working port and an oil return port, and the oil inlet is connected to the working port when the two-position three-way solenoid valve is in an electrical potential, and the working port is connected to the oil return port when the two-position three-way solenoid valve is in a non-electrical potential; a first pressure reducing valve is provided on the hydraulic oil main pipeline, an injection head brake pressure sensor is connected on the first hydraulic pipeline and located between the injection head brake control solenoid valve and the second end of the first hydraulic pipeline, and a roller brake pressure sensor is connected on the second hydraulic pipeline and located between the roller brake control solenoid valve and the second end of the second hydraulic pipeline.

[0024] The present invention also provides an injection head emergency shutdown automatic control method, the injection head emergency shutdown automatic control method comprises the following steps:

[0025] Setting a preset minimum weight value, a preset maximum weight value, and a preset maximum weight change rate;

[0026] Real-time detection of the combined force on the coiled tubing in the well;

[0027] Compare the resultant force with the preset minimum weight value and the preset maximum weight value, and compare the rate of change of the resultant force with the preset maximum weight change rate; when the resultant force is less than the preset minimum weight value, or greater than the preset maximum weight value, or the rate of change of the resultant force is greater than the preset maximum weight change rate, control the injection head pump to relieve pressure and stop, and control the injection head brake to brake after the injection head pump relieves pressure and stops.

[0028] In a preferred embodiment of the present invention, the injection head emergency shutdown automatic control method further comprises the following steps:

[0029] Set a preset minimum speed;

[0030] The running speed of the coiled tubing is detected in real time. When the change rate of the resultant force is greater than the preset maximum weight change rate and the detected running speed of the coiled tubing is greater than the preset minimum speed, the injection head pump is controlled to relieve pressure and stop.

[0031] In a preferred embodiment of the present invention, after the injection head pump stops rotating due to pressure relief, the injection head brake is controlled to brake only after a preset time delay or after it is detected that the running speed of the coiled tubing returns to zero.

[0032] In a preferred embodiment of the present invention, the injection head emergency shutdown automatic control method is implemented by the above-mentioned injection head emergency shutdown automatic control system.

[0033] As described above, the automatic control system for emergency shutdown of the injection head in the present invention cooperates with the load sensor, the control loop and the acquisition control module, and sets the preset minimum weight value, the preset maximum weight value and the preset maximum weight change rate according to the actual working conditions. The load pressure detected by the load sensor can be used to calculate the resultant force of the coiled tubing, and the resultant force is compared with the three preset limit values. When it is not within the preset limit value range, the acquisition control module automatically issues a command to first control the injection head pump to relieve pressure and stop, and then control the injection head brake to brake. The whole system makes the injection head operation safer and more convenient, and can make real-time predictions and automatic identifications, and stop the injection head in time when the coiled tubing is blocked or stuck, thereby eliminating the risk of the coiled tubing being squeezed or broken; it changes the control mode of the existing injection head passively shutting down due to pressure holding when the coiled tubing is blocked or stuck, and the present invention can automatically control and implement active pressure relief and shutdown under abnormal working conditions of the injection head, thereby improving the safety and reliability of the injection head; it avoids the disadvantage of the coiled tubing being damaged due to fatigue or lack of concentration caused by long-term manual operation, liberates labor and reduces construction risks, and conforms to the trend of the development of coiled tubing operation equipment towards automation and intelligence.

[0034] The automatic control method for emergency shutdown of the injection head in the present invention can more comprehensively predict the situation of the coiled tubing encountering obstruction or jamming by collecting the resultant force on the coiled tubing in real time and setting three limit values ​​of a preset minimum weight value, a preset maximum weight value and a preset maximum weight change rate, and can trigger the emergency shutdown in time, and actively relieve pressure to stop and brake, thereby greatly improving the safety and reliability of the injection head. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The following drawings are intended only to illustrate and explain the present invention, and are not intended to limit the scope of the present invention.

[0036] Figure 1 : A structural diagram of the injection head provided by the present invention in cooperation with a load sensor and a speed acquisition device.

[0037] Figure 2 : The schematic diagram of the control loop provided by the present invention when adopting the first method.

[0038] Figure 3 :for Figure 2 Enlarged view of the first hydraulic pipeline.

[0039] Figure 4 :for Figure 2 Enlarged view of the second hydraulic pipeline.

[0040] Figure 5 :for Figure 2 Enlarged view of the third hydraulic pipeline.

[0041] Figure 6 : The schematic diagram of the control loop provided by the present invention when the second mode is adopted.

[0042] Description of Figure Numbers:

[0043] 1. Load sensor;

[0044] 2. Speed ​​acquisition device;

[0045] 3. Control loop;

[0046] 31. Hydraulic oil main pipeline; 311. Total pressure gauge; 312. First pressure reducing valve;

[0047] 32, first hydraulic pipeline; 321, injection head manual brake control valve; P3, third oil inlet; T3, third oil return port; A3, third working port; 322, injection head brake control solenoid valve; P1, first oil inlet; T1, first oil return port; A1, first working port; 323, injection head brake pressure sensor;

[0048] 33, second hydraulic pipeline; 331, drum manual brake control valve; P4, fourth oil inlet; T4, fourth oil return port; A4, fourth working port; 332, second pressure gauge; 333, drum brake control solenoid valve; P6, sixth oil inlet; T6, sixth oil return port; A6, sixth working port; 334, drum brake pressure sensor;

[0049] 34, third hydraulic pipeline; 341, second pressure reducing valve; 342, hydraulically controlled reversing valve; P5, fifth oil inlet; T5, fifth oil return port; A5, fifth working port; X, control oil port; 343, injection head displacement control solenoid valve; P2, second oil inlet; T2, second oil return port; A2, second working port; 344, third pressure reducing valve; 345, hydraulically controlled proportional direction control handle; 346, shuttle valve; 3461, first pressure gauge;

[0050] 4. Injection head; 41. Base; 411. Door-type carrier; 42. Frame; 43. Box; 431. Rotating shaft; 432. Box pressure rod; 44. Guide; 45. Passive sprocket. DETAILED DESCRIPTION

[0051] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described with reference to the accompanying drawings.

[0052] like Figures 1 to 6 As shown, this embodiment provides an injection head emergency shutdown automatic control system, including:

[0053] The load sensor 1 is used to be arranged on the injection head 4, and can detect in real time the load pressure on the load sensor 1 after the combined force (also called the coiled tubing load) exerted on the coiled tubing in the well is transmitted to the injection head 4;

[0054] Control circuit 3, control circuit 3 is used to connect with the injection head brake;

[0055] And a collection control module, the collection control module is electrically connected to the load sensor 1 and the control circuit 3, and the collection control module can obtain the resultant force exerted on the coiled tubing according to the load pressure detected by the load sensor 1; when the resultant force is less than a preset minimum weight value, or greater than a preset maximum weight value, or the change rate of the resultant force is greater than a preset maximum weight change rate, the collection control module can control the injection head pump to depressurize and stop, and control the injection head brake to brake after the injection head pump depressurizes and stops.

[0056] Specifically, the comprehensive force of the coiled tubing after entering the well will be collected and calculated by the load sensor 1 installed on the injection head 4. When encountering unpredictable sticking force or resistance in the well during the lifting and lowering operation, the load (weight) will change suddenly. By sensing the abnormal load, it can be judged that the operation of the coiled tubing is blocked or stuck. The acquisition control module is a signal acquisition and instruction issuing unit, which is installed in the control room. It collects the load signal (i.e., the load pressure signal detected by the load sensor 1) in real time, and implements program judgment and automatic control. It is the control center of the entire system. By writing a monitoring program in the controller of the acquisition control module and implementing automatic control, a preset minimum weight value is set, and a preset maximum weight value is set to avoid overpressure or over-tension of the coiled tubing when it encounters resistance or jamming; a preset maximum weight change rate is set, and the emergency shutdown automatic control system continuously monitors the calculated resultant force of the coiled tubing, and compares the resultant force at any given time with the resultant force of the previous second. If the system detects that the change rate of the resultant force exceeds the preset maximum weight change rate, the emergency shutdown program of the injection head 4 is executed, first controlling the injection head pump to depressurize and stop, and then controlling the injection head brake to brake.

[0057] Therefore, the injection head emergency shutdown automatic control system in this embodiment, through the cooperation of the load sensor 1, the control loop 3 and the acquisition control module, and the preset minimum weight value, the preset maximum weight value and the preset maximum weight change rate are set according to the actual working conditions. The load pressure detected by the load sensor 1 can be used to calculate the resultant force of the coiled tubing, and the resultant force is compared with the three preset limit values. When it is not within the preset limit value range, the acquisition control module automatically issues a command to first control the injection head pump to relieve pressure and stop, and then control the injection head brake to brake. The whole system makes the operation of the injection head 4 safer and more convenient, and can predict and automatically identify in real time, and stop the injection head 4 in time after the coiled tubing is blocked or stuck, thereby eliminating the risk of the coiled tubing being squeezed or broken; the control mode of the passive pressure holding and shutdown of the injection head 4 after the existing coiled tubing is blocked or stuck is changed, and the present embodiment can perform automatic control, implement active pressure relief and shutdown under abnormal working conditions of the injection head 4, and improve the safety and reliability of the injection head 4; avoid the disadvantage of the coiled tubing being damaged due to fatigue or lack of concentration caused by long-term manual operation, liberate labor and reduce construction risks, and meet the trend of the development of coiled tubing operation equipment towards automation and intelligence.

[0058] In a specific implementation, the load sensor 1 is a bidirectional load sensor and is disposed on the box pressure rod 432 of the injection head 4 .

[0059] Among them, the structure of the injection head 4 itself is the existing technology, such as Figure 1As shown, the injection head 4 is mainly composed of a base 41, a frame 42, a box 43 and a guide 44. The guide 44 is installed on the top of the frame 42 through a slide seat to guide the continuous tube. The bottom of the frame 42 is connected to the ear seats at the four corners of the base 41 through four pins. The main function of the frame 42 is to connect the upper guide 44 and the lower base 41 and the protective box 43 and the parts or components installed on it. The box body 43 is equipped with driving mechanisms such as a hydraulic motor and a reducer, as well as a chain and a clamping mechanism, and is the main part for clamping the continuous pipe to lift and lower; the box body 43 is connected to the base 41 through a rotating shaft 431 and an ear seat on one side of the lower side, and the non-rotating shaft joint on the other side is composed of a door-type bearing frame 411 welded on the base 41 and a box body pressure rod 432. The box body pressure rod 432 can be slidably arranged in the door-type bearing frame 411 up and down, and the top of the base 41 and the door-type bearing frame 411 is used to limit the up and down movement position of the box body pressure rod 432, and the bidirectional load sensor is installed on the box body pressure rod 432.

[0060] The coiled tubing is clamped on the inner side of the left and right hanging chains. After a certain length of the coiled tubing is inserted into the well, the downward pulling force or upward pushing force F1 of the tubing string is transmitted to the chain and the clamping mechanism, and then transmitted to the box body 43. One side of the lower side of the box body 43 is the rotating shaft 431, and the downward or upward pressure F2 on the other side is pressed on the bidirectional load sensor. The force arms of F1 and F2 relative to the rotating shaft 431 are recorded as F1′ and F2′, F1F1′=F2F2′, and the force arm is fixed. Therefore, by detecting F2 in real time through the load sensor 1, the actual downward pulling force or upward pushing force F1 can be monitored, that is, the resultant force of the coiled tubing can be obtained.

[0061] The load sensor 1 mentioned above can be an electronic load sensor or a hydraulic load sensor. When an electronic load sensor is used, a bidirectional load sensor can be formed by installing an electronic load sensor at the box pressure rod 432; when a hydraulic load sensor is used, two hydraulic load sensors need to be installed at the box pressure rod 432 to form a bidirectional sensor. By installing the bidirectional load sensor at the box pressure rod 432 (that is, the junction of the base 41 of the injection head 4 and the non-rotating shaft side of the box 43), the resultant force (also understood as weight) of the continuous pipe after entering the well can be indirectly detected, and the acquisition control module performs signal processing on the positive load (heavy pipe) or negative load (light pipe).

[0062] Furthermore, the injection head emergency shutdown automatic control system also includes a speed acquisition device 2, which can be used to detect the running speed of the coiled tubing in real time, and the acquisition control module is electrically connected to the speed acquisition device 2. The running speed of the coiled tubing can be acquired through the speed acquisition device 2, and is also used for operators to understand the speed of the tripping string.

[0063] Preferably, the acquisition control module controls the injection head pump to depressurize and stop only when the change rate of the resultant force is greater than the preset maximum weight change rate and the running speed of the coiled tubing detected by the speed acquisition device 2 is greater than the preset minimum speed. In this way, the preset minimum speed and the preset maximum weight change rate work together as a protection to prevent the emergency stop automatic control system from accidentally stopping the injection head 4, that is, the criterion of the preset maximum weight change rate has a chance to trigger the emergency stop of the injection head 4 only when it is above the preset minimum speed, thus filtering out the normal start and stop of the injection head 4 or the sudden change of the load when the coiled tubing passes through the bend in the formation, avoiding frequent triggering of the system to stop by mistake.

[0064] Generally, after the injection head 4 stops rotating due to pressure relief, the roller also stops rotating accordingly, and finally the coiled tubing stops moving and the speed returns to zero. However, it usually takes several seconds from the injection head 4 stopping to the coiled tubing speed returning to zero, and the injection head brake is a parking brake, which can only brake statically. In order to ensure safe use, the injection head brake should be controlled for safe braking after the injection head 4 stops rotating and the coiled tubing speed returns to zero. As for when to control the injection head brake for braking, for example, it can be achieved as follows: the acquisition control module can control the injection head brake through the control loop 3 after the injection head pump stops rotating due to pressure relief, and when the running speed detected by the speed acquisition device 2 is zero. It can be understood that when the running speed detected by the speed acquisition device 2 is zero, it does not mean that the running speed is the absolute zero speed of the coiled tubing. When the running speed of the coiled tubing is very close to zero speed, the running speed detected by the speed acquisition device 2 is displayed as zero.

[0065] For another example, the automatic control system for emergency shutdown of the injection head may also include a timer, the acquisition control module is electrically connected to the timer, and the injection head brake may be controlled through the control loop 3 only after the injection head pump stops depressurizing and the timer counts a preset time. The specific preset time should be the time from the injection head 4 stopping to the coiled tubing speed being zero, which may be set after relevant tests.

[0066] In order to facilitate real-time detection of the running direction and speed of the coiled tube, the speed acquisition device 2 includes a speed encoder. The acquisition control module is electrically connected to the speed encoder and can acquire the speed signal detected by the speed encoder in real time. The position of the speed encoder can be selected as follows:

[0067] The first position setting: Figure 1 As shown, the speed encoder is arranged on the passive sprocket 45 of the injection head 4 (there are four passive sprockets 45 on the injection head 4, and the speed encoder can be arranged on any one of the passive sprockets 45). At this time, the speed encoder can be coaxially mounted on the passive sprocket 45 through a coupling.

[0068] The second position setting: a friction wheel is arranged on the box 43 of the injection head 4, on the guide pressure box of the injection head 4, or on the roller for winding the continuous tube, and the friction wheel can be pressed on the surface of the continuous tube, and the speed encoder is arranged on the friction wheel. At this time, a corresponding elastic pressing mechanism is also provided, which can press the wheel surface of the friction wheel on the outer surface of the continuous tube to ensure that the wheel surface of the friction wheel and the surface of the continuous tube are in reliable contact; the speed encoder can be coaxially connected to the friction wheel through a coupling, or connected to the friction wheel through a chain; when the continuous tube moves up and down, it will drive the friction wheel to rotate forward and reverse, thereby driving the speed encoder to operate.

[0069] The above two position settings are detected in real time by the speed encoder, and the running speed of the coiled tubing can be converted after corresponding calculation to realize the speed measurement of the coiled tubing starting and stopping. Of course, in addition to the above two position settings being detected in a contact manner, the speed encoder can also use a non-contact method (such as laser, ray) to measure the speed, and this embodiment is only for example.

[0070] Furthermore, the above-mentioned method of controlling the shutdown of the injection head pump and the braking of the injection head brake by cooperating with the acquisition control module and the control loop 3 can be adopted in the following two ways:

[0071] First way:

[0072] like Figures 2 to 5 As shown, the control circuit 3 is also used to connect with the injection head pump and the drum brake. The injection head pump is a hydraulically controlled proportional pump. The control circuit 3 includes a hydraulic oil main pipeline 31, a first hydraulic pipeline 32, a second hydraulic pipeline 33 and a third hydraulic pipeline 34. The first hydraulic pipeline 32 is provided with an injection head manual brake control valve 321 and an injection head brake control solenoid valve 322 in sequence from the first end to the second end thereof, the second hydraulic pipeline 33 is provided with a drum manual brake control valve 331, and the third hydraulic pipeline 34 is provided with a hydraulically controlled reversing valve 342, an injection head displacement control solenoid valve 343 and a hydraulically controlled proportional direction control handle 345 in sequence from the first end to the second end thereof.

[0073] The first end of the first hydraulic pipeline 32 is connected to the outlet end of the hydraulic oil main pipeline 31, and the second end of the first hydraulic pipeline 32 is used to connect to the injection head brake. The first end of the second hydraulic pipeline 33 is connected to the outlet end of the hydraulic oil main pipeline 31, and the second end of the second hydraulic pipeline 33 is used to connect to the drum brake. The first end of the third hydraulic pipeline 34 is connected to the hydraulic oil main pipeline 31, and the control oil port X of the hydraulic control reversing valve 342 is connected to the second hydraulic pipeline 33 through the corresponding pipeline, and the connection point is located between the drum manual brake control valve 331 and the second end of the second hydraulic pipeline 33, and the two output ports of the hydraulic control proportional direction control handle 345 are respectively connected to the two hydraulic proportional control ports of the injection head pump. The acquisition control module can control the injection head displacement control solenoid valve 343 to be energized to depressurize the injection head pump and stop it; and can control the injection head brake control solenoid valve 322 to be energized to brake the injection head brake.

[0074] Among them, the injection head manual brake control valve 321 and the drum manual brake control valve 331 are both manual control valves. The injection head manual brake control valve 321 is used to manually control the braking or releasing of the injection head brake, and the drum manual brake control valve 331 is used to manually control the braking or releasing of the drum brake. The hydraulically controlled reversing valve 342 can use the reversal of hydraulic oil to control the on-off of the third hydraulic pipeline 34 here, specifically, the reversal of the hydraulically controlled reversing valve 342 can be realized after the drum brake is released, so that the hydraulic oil can flow to the hydraulically controlled proportional direction control handle 345. The injection head brake control solenoid valve 322 is used to control the braking of the injection head brake under abnormal working conditions of the injection head 4, and the injection head displacement control solenoid valve 343 is used to control the injection head pump to relieve pressure and stop under abnormal working conditions of the injection head 4. The hydraulically controlled proportional direction control handle 345 is mainly used to control the forward or backward direction of the injection head pump by manual pushing and pulling. By controlling the opening size of the hydraulically controlled proportional direction control handle 345 and the pressure of the hydraulic oil in the third hydraulic pipeline 34, the forward or backward speed of the injection head pump can be controlled.

[0075] When in use, the input end of the hydraulic oil main pipeline 31 is connected to the hydraulic system pump station (for providing hydraulic oil), the second end of the first hydraulic pipeline 32 is connected to the injection head brake, the second end of the second hydraulic pipeline 33 is connected to the roller brake, and the two output ports of the hydraulic proportional direction control handle 345 on the third hydraulic pipeline 34 are respectively connected to the two hydraulic proportional control ports of the injection head pump.

[0076] Under normal circumstances, the injection head brake control solenoid valve 322 and the injection head displacement control solenoid valve 343 are both in a power-off state, the first hydraulic pipeline 32 is in a passage state at the position of the injection head brake control solenoid valve 322, and the third hydraulic pipeline 34 is in a passage state at the position of the injection head displacement control solenoid valve 343. These two solenoid valves do not affect the normal control of manual operation. At this time, the working state of the injection head 4 can be controlled by manually controlling the injection head manual brake control valve 321, the drum manual brake control valve 331 and the hydraulic proportional direction control handle 345. When the injection head manual brake control valve 321 is manually adjusted to the first working position (i.e. Figure 2 When the manual brake control valve 321 of the injection head is manually adjusted to the upper position (i.e., the upper position shown in FIG), the hydraulic oil flows to the injection head brake after passing through the injection head manual brake control valve 321 and the injection head brake control solenoid valve 322, and the injection head brake is in the released state (i.e., the brake is released); when the manual brake control valve 321 of the injection head is manually adjusted to the second working position (i.e., Figure 2 When the injection head brake is in the lower position shown in the figure, the control oil of the injection head brake is forcibly released, and the injection head brake is in a braking state, achieving reliable braking.

[0077] When the injection head 4 needs to be started, the manual adjustment drum manual brake control valve 331 is in the first working position (i.e. Figure 2 ), the hydraulic oil flows to the drum brake through the drum manual brake control valve 331, and the drum brake is in the released state (i.e., the brake is released); at this time, the hydraulic oil also flows into the control oil port X of the hydraulic control reversing valve 342 through the corresponding pipeline after passing through the drum manual brake control valve 331, so that the hydraulic control reversing valve 342 is in the first working position (i.e., Figure 2 The third hydraulic line 34 is connected at the position of the hydraulic control reversing valve 342, and the hydraulic oil enters the hydraulic control proportional direction control handle 345 after passing through the hydraulic control reversing valve 342 and the injection head displacement control solenoid valve 343. Then, the hydraulic control proportional direction control handle 345 is manually pushed forward or pulled backward, and the hydraulic oil is output to the injection head pump from the corresponding output port of the hydraulic control proportional direction control handle 345 to control the forward or backward direction and displacement size of the injection head pump.

[0078] When the injection head 4 needs to be stopped, first adjust the hydraulic proportional direction control handle 345 to the middle position; then manually adjust the drum manual brake control valve 331 to the second working position (i.e. Figure 2 When the control oil of the drum controller is forcibly depressurized, the drum brake is in a braking state, and the drum brake is realized; at this time, the control oil port X of the hydraulic control reversing valve 342 is no longer supplied with hydraulic oil, and the hydraulic control reversing valve 342 is in the second working position (i.e. Figure 2The third hydraulic line 34 is disconnected at the position of the hydraulically controlled reversing valve 342, and the hydraulic signal cannot be sent to the injection head displacement control solenoid valve 343 through the hydraulically controlled reversing valve 342, so that the hydraulically controlled proportional direction control handle 345 cannot obtain the hydraulic signal, and the injection head pump has no direction and displacement signal, and the injection head pump is depressurized and stops.

[0079] When the injection head 4 has an abnormal working condition, that is, the acquisition control module detects that the resultant force of the coiled tubing is less than the preset minimum weight value, or the resultant force is greater than the preset maximum weight value, or the running speed of the coiled tubing is greater than the preset minimum speed and the change rate of the resultant force is greater than the preset maximum weight change rate and the resultant force change rate, the injection head displacement control solenoid valve 343 is first triggered to be energized, so that the third hydraulic pipeline 34 is disconnected at the position of the injection head displacement control solenoid valve 343, the direction and displacement signals of the injection head pump are reset to zero, the injection head pump returns to the middle position, the output flow is reset to zero, and the injection head pump is depressurized and stopped. After that, after a preset delay time (for example, 3 seconds) or when it is detected that the coiled tubing speed has returned to zero, the injection head brake control solenoid valve 322 is controlled to be energized, the injection head brake control solenoid valve 322 is switched to the lower position, the injection head brake control oil pressure is forcibly released, and the injection head brake is safely braked.

[0080] It can be understood that, since the electro-hydraulic automatic control is at a priority level compared to manual operation, when the injection head displacement control solenoid valve 343 is triggered to be energized to realize the shutdown of the injection head pump, no matter what state the hydraulic proportional direction control handle 345 is in, it will not affect the injection head pump's inclined plate to return to the center position (no oil pressure output); similarly, when the injection head brake control solenoid valve 322 is energized, no matter what working position the injection head manual brake control valve 321 is in, it will not affect the injection head brake to brake safely in time. At the same time, the drum brake can lock the direction control of the injection head pump through the hydraulic reversing valve 342 to prevent the drum brake from being released and the injection head 4 from being unilaterally started, resulting in damage to the guide 44 or the drum of the injection head 4.

[0081] Therefore, in the first method mentioned above, the traditional manual operation function is still retained, and the automatic monitoring and control function of real-time prediction and identification is added as a supplement to manual operation. The manual operation mode combined with the auxiliary automatic prediction and disposal method does not affect the manual operation function, and when the injection head 4 has an abnormal working condition, it can take precedence over manual operation to implement the pressure relief shutdown and brake of the injection head 4. By switching the injection head displacement control solenoid valve 343 used to control the injection head pump displacement, the injection head pump quickly returns to the middle position, and the output flow returns to zero, causing the injection head 4 to be pressure relieved and stopped; after the preset time is delayed or the coiled tubing speed is detected to be zero, the injection head brake control solenoid valve 322 used to control the injection head brake oil pressure is switched, and the injection head brake is safely braked; then the injection head 4 is stopped in time after the coiled tubing is blocked or stuck, eliminating the risk of the coiled tubing being squeezed or broken; and active pressure relief shutdown is realized, which greatly improves the safety and reliability of the injection head 4, reflects the automation and information level of the coiled tubing operation machine, and can liberate labor while making the whole machine operation safer and more convenient.

[0082] Furthermore, if Figure 2 As shown, the injection head brake control solenoid valve 322 and the injection head displacement control solenoid valve 343 are both two-position three-way solenoid valves, and both have an oil inlet, a working port and an oil return port. When the two-position three-way solenoid valve is in a de-energized state, the oil inlet is connected to the working port, and when the two-position three-way solenoid valve is in a energized state, the working port is connected to the oil return port. In this way, when the two solenoid valves are in a de-energized state (i.e., a spring position), the manual operation function is not affected, and the use is more convenient.

[0083] More specifically, if Figure 3 As shown, the injection head brake control solenoid valve 322 has a first oil inlet P1, a first oil return port T1 and a first working port A1. The first oil inlet P1 and the first working port A1 are connected in series in the first hydraulic pipeline 32. The first oil return port T1 is connected to the corresponding oil return pipeline for unloading the oil pressure. The injection head brake control solenoid valve 322 has a power-off working position and a power-on working position. When the injection head 4 is working normally, the injection head brake control solenoid valve 322 loses power and is in the power-off working position (i.e. Figure 2 The first oil inlet P1 is connected to the first working port A1, and the hydraulic oil can flow to the injection head brake through the injection head brake control solenoid valve 322; when the injection head 4 has an abnormal working condition, the injection head brake control solenoid valve 322 is energized and in the energized working position (i.e. Figure 2 At this time, the first working port A1 is connected to the first oil return port T1, and the control oil injected into the head brake is forcibly depressurized through the first oil return port T1.

[0084] like Figure 5As shown, the injection head displacement control solenoid valve 343 has a second oil inlet P2, a second oil return port T2 and a second working port A2. The second oil inlet P2 and the second working port A2 are connected in series in the third hydraulic pipeline 34, and the second oil return port T2 is connected to the corresponding oil return pipeline. The injection head displacement control solenoid valve 343 has a power-off working position and a power-on working position. When the injection head 4 is working normally, the injection head displacement control solenoid valve 343 is power-off and is in the power-off working position (i.e. Figure 2 The second oil inlet P2 is connected to the second working port A2, and the hydraulic oil can flow to the hydraulic proportional direction control handle 345 through the injection head displacement control solenoid valve 343; when the injection head 4 has an abnormal working condition, the injection head displacement control solenoid valve 343 is energized and in the energized working position (i.e. Figure 2 At this time, the second working port A2 is connected to the second oil return port T2, so that the hydraulic proportional direction control handle 345 cannot obtain the hydraulic signal.

[0085] The injection head manual brake control valve 321 and the drum manual brake control valve 331 are both two-position three-way valves, and the position switching is realized by manual operation. Figure 3 As shown, the injection head manual brake control valve 321 has a third oil inlet P3, a third oil return port T3 and a third working port A3, the third oil inlet P3 and the third working port A3 are connected in series in the first hydraulic pipeline 32, and the third oil return port T3 is connected to the corresponding oil return pipeline. The injection head manual brake control valve 321 has a first working position and a second working position. When the injection head manual brake control valve 321 is in the first working position, the third oil inlet P3 and the third working port A3 are connected, and under normal circumstances, the hydraulic oil can flow into the injection head brake through the injection head manual brake control valve 321; when the injection head manual brake control valve 321 is in the second working position, the third working port A3 is connected with the third oil return port T3, and under normal circumstances, the control oil of the injection head brake can be forcibly unloaded through the third oil return port T3.

[0086] like Figure 4 As shown, the drum manual brake control valve 331 has a fourth oil inlet P4, a fourth oil return port T4 and a fourth working port A4, the fourth oil inlet P4 and the fourth working port A4 are connected in series in the second hydraulic pipeline 33, and the fourth oil return port T4 is connected to the corresponding oil return pipeline. The drum manual brake control valve 331 has a first working position and a second working position. When the drum manual brake control valve 331 is in the first working position, the fourth oil inlet P4 is connected to the fourth working port A4, and under normal circumstances, the hydraulic oil can flow into the drum brake through the drum manual brake control valve 331; when the drum manual brake control valve 331 is in the second working position, the fourth working port A4 is connected to the fourth oil return port T4, and under normal circumstances, the control oil of the drum brake can be forcibly unloaded through the fourth oil return port T4.

[0087] The above-mentioned hydraulically controlled reversing valve 342 is a two-position three-way valve, and uses oil pressure to achieve reversal. It has a fifth oil inlet P5, a fifth oil return port T5, a fifth working port A5 and a control oil port X. The fifth oil inlet P5 and the fifth working port A5 are connected in series to the third hydraulic pipeline 34, the fifth oil return port T5 is connected to the corresponding oil return pipeline, and the control oil port X is connected to the second hydraulic pipeline 33 through the corresponding pipeline. The hydraulically controlled reversing valve 342 has a first working position and a second working position. When hydraulic oil is introduced into the control oil port X, the hydraulically controlled reversing valve 342 is in the first working position, the fifth oil inlet P5 is connected with the fifth working port A5, and under normal circumstances, the hydraulic oil can flow into the hydraulically controlled proportional direction control handle 345 through the hydraulically controlled reversing valve 342; when no hydraulic oil is introduced into the control oil port X, the hydraulically controlled reversing valve 342 is in the second working position, the fifth working port A5 is connected with the fifth oil return port T5, and under normal circumstances, the hydraulically controlled proportional direction control handle 345 cannot obtain a hydraulic signal.

[0088] Furthermore, in order to meet the pressure requirements of each pipeline, a first pressure reducing valve 312 is provided on the hydraulic oil main pipeline 31 and located between the first end of the third hydraulic pipeline 34 and the outlet end of the hydraulic oil main pipeline 31, and a second pressure reducing valve 341 and a third pressure reducing valve 344 are provided in sequence on the third hydraulic pipeline 34 and located between the first end thereof and the hydraulic proportional direction control handle 345. Two pressure reducing valves are provided on the third hydraulic pipeline 34 to achieve two-stage pressure reduction, which can not only make the pressure regulation more stable, but also can still achieve the pressure reducing function when one of the pressure reducing valves fails, and play a certain protective role on the hydraulic proportional direction control handle 345. Generally, the second pressure reducing valve 341 is provided at the front end of the hydraulic control reversing valve 342 to prevent the high pressure from impacting the valve core of the hydraulic control reversing valve 342 after the reversal; the positions of the injection head displacement control solenoid valve 343 and the third pressure reducing valve 344 are interchangeable.

[0089] In order to more conveniently understand the pressure of the hydraulic oil output after passing through the hydraulic proportional direction control handle 345, a shuttle valve 346 is connected to the hydraulic proportional direction control handle 345 or a shuttle valve 346 is integrated in the hydraulic proportional direction control handle 345, and the two inlets of the shuttle valve 346 are respectively connected to the two output ports of the hydraulic proportional direction control handle 345, and the outlet of the shuttle valve 346 is connected to a pressure gauge (i.e., the first pressure gauge 3461). Generally, a total pressure gauge 311 is connected to the hydraulic oil main pipeline 31 and located before the first pressure reducing valve 312, and a second pressure gauge 332 is connected to the second hydraulic pipeline 33 and located at the connection point between the hydraulic control reversing valve 342 and the second hydraulic pipeline 33, so as to detect the pressure at the corresponding position.

[0090] More specifically, the hydraulic proportional direction control handle 345 has an oil inlet, an oil drain and two output ports. The oil inlet is connected to the second end of the third hydraulic line 34, the oil drain is connected to the corresponding oil drain circuit, and the two output ports are respectively used to connect to the two hydraulic proportional control ports of the injection head pump; by manually pushing and pulling the handle, the output port on which side can output hydraulic oil, thereby driving the injection head 4 forward or backward. The shuttle valve 346 has two inlets and one outlet, and its two inlets are respectively connected to the two output ports of the hydraulic proportional direction control handle 345. When in use, the side with higher pressure in the two inlets will be connected to the outlet, and the first pressure gauge 3461 detects the pressure value on the high-pressure side, so that the staff can understand the pressure (pump control signal) output by the hydraulic proportional direction control handle 345.

[0091] In the first mode, the injection head pump should be a hydraulically controlled proportional pump, which can be a closed injection head pump or an open injection head pump. When the injection head pump adopts a closed injection head pump, it has a proportional reversing function, and its two hydraulic proportional control ports are respectively connected to the two output ports of the hydraulically controlled proportional direction control handle 345 to control the direction and swing angle of the swash plate of the closed injection head pump; when the direction and displacement signals of the injection head pump return to zero, the swash plate of the closed injection head pump quickly returns to the center position. When the injection head pump adopts an open injection head pump, the outlet of the open injection head pump will be connected to a hydraulically controlled proportional reversing valve. The two hydraulic proportional control ports of the hydraulically controlled proportional reversing valve are respectively connected to the two output ports of the hydraulically controlled proportional direction control handle 345, so as to control the reversing of the hydraulically controlled proportional reversing valve at the outlet of the injection head open pump, and then control the forward or backward direction and speed of the injection head; when the pressure of any output port of the hydraulically controlled proportional direction control handle 345 returns to zero, the controlled hydraulically controlled proportional reversing valve returns to the center position (no oil pressure passes through the hydraulically controlled proportional reversing valve to drive the injection head 4), and the injection head pump will automatically return to the small displacement.

[0092] Second way:

[0093] like Figure 6 As shown, the injection head emergency shutdown automatic control system also includes an electric proportional direction control handle and a potentiometer electrically connected to the acquisition control module. The acquisition control module is also used to be electrically connected to the injection head pump, and the injection head pump is an electric proportional closed pump. The control circuit 3 includes a hydraulic oil main pipeline 31 and a first hydraulic pipeline 32. An injection head brake control solenoid valve 322 is provided on the first hydraulic pipeline 32. The first end of the first hydraulic pipeline 32 is connected to the outlet end of the hydraulic oil main pipeline 31, and the second end of the first hydraulic pipeline 32 is used to connect to the injection head brake. The acquisition control module can relieve pressure and stop the injection head pump by returning the electrical signal of the injection head pump to zero; and can control the injection head brake control solenoid valve 322 to lose power so that the injection head brake is safely braked.

[0094] Preferably, in order to achieve the locking of the direction control of the injection head pump by the roller brake, the control circuit 3 also includes a second hydraulic pipeline 33, on which a roller brake control solenoid valve 333 is provided, the first end of the second hydraulic pipeline 33 is connected to the outlet end of the hydraulic oil main pipeline 31, and the second end of the second hydraulic pipeline 33 is used to connect to the roller brake. After the roller brake control solenoid valve 333 is in the energized position, the acquisition control module can control the injection head pump to obtain an electrical signal. That is, when the roller brake control solenoid valve 333 is in the de-energized position, no matter how the electric proportional direction control handle is pushed or pulled, the acquisition control module will not send an electrical signal to the injection head pump, and the injection head 4 cannot be started. Only after the roller brake control solenoid valve 333 is in the energized position can the injection head 4 be started, which effectively prevents the unilateral startup of the injection head 4 without releasing the roller brake, resulting in damage to the guide 44 or the roller of the injection head 4.

[0095] In detail, in the second method, the injection head pump should be an electric proportional closed pump, which has its own electric proportional directional control valve. The electric proportional directional control valve has an electromagnetic coil that can adjust the swash plate angle and direction of the electric proportional closed pump by receiving electrical signals.

[0096] The electric proportional direction control handle and the potentiometer are both located on the operating table of the electric control room. The signals of the two are connected in series (ie electrically connected). The potentiometer is located at the front end of the electric proportional direction control handle. After manually pushing and pulling the handle to adjust, the electric proportional direction control handle can send the electric signal (referred to as the first electric signal) used to control the direction of the electric proportional closed pump and the swash plate swing angle to the controller in the acquisition control module. The potentiometer is used to adjust the voltage or current. After manually twisting the potentiometer, the potentiometer can send the voltage or current signal (referred to as the second electric signal) to the controller.

[0097] When in use, the input end of the hydraulic oil main pipeline 31 is connected to the hydraulic system pump station, the second end of the first hydraulic pipeline 32 is connected to the injection head brake, and the second end of the second hydraulic pipeline 33 is connected to the drum brake.

[0098] Under normal circumstances, the injection head brake control solenoid valve 322 and the drum brake control solenoid valve 333 are both in the energized state, the first hydraulic pipeline 32 is in the access state at the position of the injection head brake control solenoid valve 322, and the second hydraulic pipeline 33 is in the access state at the position of the drum brake control solenoid valve 333. The hydraulic oil can flow into the injection head brake and the drum brake through the injection head brake control solenoid valve 322 and the drum brake control solenoid valve 333 respectively, so that the injection head brake and the drum brake are both in the released state (i.e., the brake is released). The program can be set so that only after the drum brake control solenoid valve 333 is energized, the electric proportional direction control handle is manually pushed and pulled, and the potentiometer is screwed and adjusted, the electric proportional direction control handle sends a first electrical signal to the controller, and the potentiometer sends a second electrical signal to the controller. After the controller collects the first electrical signal and the second electrical signal, it sends an electrical signal to the injection head pump to realize the forward or backward direction and speed control of the injection head 4.

[0099] Under normal circumstances, when the injection head pump needs to be stopped, manually adjust the electric proportional direction control handle to the middle position and return the positioner signal to zero; the electric proportional closed pump receives an electric signal of zero, and the injection head pump begins to relieve pressure and stop. When the drum brake needs to be braked, the acquisition control module controls the drum brake control solenoid valve 333 to be in a de-energized state, so that the control oil of the drum brake can be relieved and the drum brake can be braked. When the injection head brake needs to be braked, the acquisition control module controls the injection head brake control solenoid valve 322 to be in a de-energized state, so that the control oil of the injection head brake can be relieved and the injection head 4 can be braked.

[0100] When the injection head 4 has an abnormal working condition, an emergency shutdown is triggered. At this time, no matter what position the electric proportional direction control handle and the potentiometer are in, the program in the controller first executes the electric signal of the injection head pump to zero, and the injection head pump starts to stop to achieve pressure relief shutdown; then after a delay of a preset time (for example, 3 seconds) or after detecting that the speed of the coiled tubing has returned to zero, the acquisition control module controls the injection head brake control solenoid valve 322 to lose power, and the injection head brake loses oil pressure and brakes.

[0101] Therefore, the second method can also realize manual operation and assist automatic prediction and disposal, which does not affect the manual operation function, and when the injection head 4 has an abnormal working condition, it can take precedence over manual operation and implement pressure relief shutdown and brake of the injection head 4, so as to stop the coiled tubing in time after it encounters resistance or jam, and realize active pressure relief shutdown, which greatly improves the safety and reliability of the injection head 4. Moreover, compared with the first method, the second method has a simpler structure and more reliable performance.

[0102] Furthermore, the injection head brake control solenoid valve 322 and the drum brake control solenoid valve 333 are both two-position three-way valves, and both have an oil inlet, a working port and an oil return port, and the oil inlet is connected to the working port when the two-position three-way solenoid valve is in a potential-enhanced state, and the working port is connected to the oil return port when the two-position three-way solenoid valve is in a potential-deactivated state. Since the power supply of the general injection head 4 and the power supply of the control circuit 3 adopt the same power supply system, when the injection head brake control solenoid valve 322 and the drum brake control solenoid valve 333 lose power, the drum brake and the injection head brake are braked, which can ensure the consistency of the power supply of the entire system and is more convenient to use.

[0103] More specifically, the injection head brake control solenoid valve 322 has a first oil inlet P1, a first oil return port T1 and a first working port A1. The first oil inlet P1 and the first working port A1 are connected in series in the first hydraulic pipeline 32, and the first oil return port T1 is connected to the corresponding oil return pipeline. The injection head brake control solenoid valve 322 has a power-off working position and a power-on working position. When the injection head 4 is working normally, the injection head brake control solenoid valve 322 is powered and is in the power-on working position (i.e. Figure 6 The first oil inlet P1 is connected to the first working port A1, and the hydraulic oil can flow to the injection head brake through the injection head brake control solenoid valve 322; when the injection head 4 needs to brake, the injection head brake control solenoid valve 322 loses power and is in the power-off working position (i.e. Figure 6 At this time, the first working port A1 is connected to the first oil return port T1, and the control oil injected into the head brake is forcibly depressurized through the first oil return port T1.

[0104] The drum brake control solenoid valve 333 has a sixth oil inlet P6, a sixth oil return port T6 and a sixth working port A6. The sixth oil inlet P6 and the sixth working port A6 are connected in series in the second hydraulic pipeline 33, and the sixth oil return port T6 is connected to the corresponding oil return pipeline. The drum brake control solenoid valve 333 has an energized working position and a de-energized working position. When the injection head 4 is working normally, the drum brake control solenoid valve 333 is energized and is in the energized working position (i.e. Figure 6 The sixth oil inlet P6 is connected to the sixth working port A6, and the hydraulic oil can flow into the drum brake through the drum brake control solenoid valve 333, and at the same time, the head pump (i.e., the electric proportional closed pump) is injected to be controlled by the potentiometer and the electric proportional direction control handle; when the drum brake is needed, the drum brake control solenoid valve 333 is de-energized and is in the de-energized working position (i.e., Figure 6 The sixth working port A6 is connected to the sixth oil return port T6, and the control oil of the drum controller can be forcibly unloaded through the sixth oil return port T6.

[0105] Furthermore, in order to meet the pressure requirements of each pipeline, a first pressure reducing valve 312 is provided on the hydraulic oil main pipeline 31. In order to facilitate the detection of the pressure at the corresponding position, an injection head brake pressure sensor 323 is connected on the first hydraulic pipeline 32 and located between the injection head brake control solenoid valve 322 and the second end of the first hydraulic pipeline 32, and a drum brake pressure sensor 334 is connected on the second hydraulic pipeline 33 and located between the drum brake control solenoid valve 333 and the second end of the second hydraulic pipeline 33.

[0106] Furthermore, the acquisition control module is a control box with built-in controller, wiring terminals, rotary buttons, alarm lights, touch screen computers and other hardware and software with control programs input, which is responsible for real-time acquisition of the load pressure signal of the load sensor 1 and the speed signal of the speed encoder, and filtering and processing, and automatically judging through the program in the controller. When the criterion for emergency shutdown of the injection head 4 is triggered, the solenoid valves of the control loop 3 are switched sequentially to execute the rapid pressure relief shutdown of the injection head 4 and the safety brake of the brake. The controller can be a PLC or a special controller, and the collected signal can be a pulse signal, a digital signal or an analog signal, which is used to analyze the collected and processed data, and has a built-in automatic control program.

[0107] The control box can also be provided with a start / stop switch and an automatic / manual mode selection switch so that the continuous tubing machine can be shut down or exit the system in special circumstances such as installation, disassembly, and pipe reversal; the sound and light alarm is used to remind when the system triggers a shutdown. Specifically, the alarm light can light up and the buzzer can sound while the injection head brake is safely braked, and the system records the alarm event; the touch screen computer control interface is provided with parameter setting, status monitoring, event browsing, and release / reset buttons, which can be touched and clicked to perform corresponding operations, such as system start / shutdown, mode switching, parameter setting, system reset, alarm event browsing, etc., which can all be controlled on the touch screen computer.

[0108] Therefore, the entire injection head emergency shutdown automatic control system, with the injection head 4 as the main body of control implementation, is composed of a load sensor 1, a speed acquisition device 2, an acquisition control module and a corresponding control loop 3. The load pressure monitored by the load sensor 1 is sent to the acquisition control module. Generally, in order to avoid load fluctuations under normal circumstances, the system filters the collected load pressure. The speed acquisition device 2 is used to detect the running direction and speed of the continuous pipe in real time, mainly through the speed encoder to measure the speed. The acquisition control module collects load and speed signals in real time, and implements program judgment and automatic control. It is the control center of the entire system; by monitoring the continuous pipe load (that is, the combined force on the continuous pipe) and the running speed of the continuous pipe, and implementing the pressure relief shutdown and braking of the injection head 4 under abnormal conditions, the safety and reliability of the injection head 4 are greatly improved, the risk of the continuous pipe being squeezed or broken is eliminated, the labor force is liberated and the construction risk is effectively reduced.

[0109] Furthermore, this embodiment also provides an injection head emergency shutdown automatic control method, the injection head emergency shutdown automatic control method comprises the following steps:

[0110] Setting a preset minimum weight value, a preset maximum weight value, and a preset maximum weight change rate;

[0111] Real-time detection of the combined force on the coiled tubing in the well;

[0112] Compare the resultant force with the preset minimum weight value and the preset maximum weight value, and compare the rate of change of the resultant force with the preset maximum weight change rate; when the resultant force is less than the preset minimum weight value, or greater than the preset maximum weight value, or the rate of change of the resultant force is greater than the preset maximum weight change rate, control the injection head pump to relieve pressure and stop, and control the injection head brake to brake after the injection head pump relieves pressure and stops.

[0113] Among them, the control method sets three judgment conditions in total, condition one: the resultant force is less than the preset minimum weight value; condition two: the resultant force is greater than the preset maximum weight value; condition three: the change rate of the resultant force is greater than the preset maximum weight change rate. By collecting the resultant force on the coiled tubing in real time, and comparing the resultant force value and the change rate of the resultant force with the above three preset values, if one of the judgment conditions is met, an emergency shutdown is triggered, that is, first unloading the pressure to stop and then safely braking. For condition three, when the coiled tubing encounters abnormal resistance or jamming in the well, the load will suddenly change, causing the change rate of the above resultant force (also known as the load change rate, that is, the change amplitude of the load detected every second compared with the previous second); the above preset maximum weight change rate (also known as the preset weight change rate upper limit) refers to the safety upper limit value when the coiled tubing encounters resistance or jamming and a sudden change in load occurs; therefore, when condition three is met, it means that the load has suddenly changed and the coiled tubing is blocked or jammed. For conditions one and two, when the coiled tubing is blocked or stuck, or when the speed is relatively low, the load change is not obvious, and the resultant force accumulates at a slower speed. At this time, condition three is not met, but in fact the coiled tubing has been blocked or stuck, and after a certain period of time, the coiled tubing will be crushed or broken; the above-mentioned preset minimum weight value (also called the preset weight lower limit) refers to the safety lower limit value to avoid overpressure of the coiled tubing, and the preset maximum weight value (also called the preset weight upper limit) refers to the safety upper limit value to avoid overtension of the coiled tubing; therefore, by setting the preset minimum weight value and the preset maximum weight value, an emergency shutdown is immediately performed when condition one or condition two is met to avoid overpressure or overtension of the coiled tubing when it is blocked or stuck.

[0114] Therefore, the entire control method can more comprehensively predict the situation where the coiled tubing encounters obstruction or jamming by collecting the resultant force on the coiled tubing in real time and setting the three limit values ​​of the preset minimum weight value, the preset maximum weight value and the preset maximum weight change rate, and can trigger the emergency shutdown in time, and actively relieve pressure to stop and brake, thereby greatly improving the safety and reliability of the injection head 4.

[0115] Preferably, the injection head emergency shutdown automatic control method further comprises the following steps:

[0116] Set a preset minimum speed;

[0117] The running speed of the coiled tubing is detected in real time. When the change rate of the resultant force is greater than the preset maximum weight change rate and the detected running speed of the coiled tubing is greater than the preset minimum speed, the injection head pump is controlled to relieve pressure and stop.

[0118] That is to say, for the above condition 3, the condition for triggering the emergency shutdown should be met only when the running speed of the coiled tubing is greater than the preset minimum speed, so as to filter out the load mutation of the injection head 4 when starting, stopping, and the coiled tubing passes through the formation bend at a low speed and cause an erroneous shutdown, and the control is more reliable. The specific setting values ​​of the preset minimum weight value, the preset maximum weight value, the preset maximum weight change rate, and the preset minimum speed can be adjusted according to the working conditions.

[0119] Generally, after the injection head pump stops running after depressurization, the injection head brake is controlled to brake only after a preset delay time or after it is detected that the running speed of the coiled tubing returns to zero to ensure safe use.

[0120] Furthermore, the entire control method can be implemented by the above-mentioned injection head emergency shutdown automatic control system. The specific control working process has been described in detail in the introduction to the control system and will not be repeated here.

[0121] In summary, the automatic control system and method for emergency shutdown of the injection head in this embodiment overcomes the risk of the coiled tube being squeezed or broken due to false adjustment of the motor pressure of the injection head 4, untimely manual prediction and untimely disposal when the injection head 4 encounters obstruction or jamming in the traditional driving and control mode of the injection head 4. The drive and control system of the injection head 4 is optimized from multiple angles such as multi-point acquisition, program control, working condition judgment and signal transmission disposal, and the original passive shutdown due to pressure holding when encountering obstruction or jamming is innovated into real-time monitoring, automatic defense and pressure relief shutdown when encountering obstruction or jamming, thereby ensuring the safety and reliability of the injection head 4 under all-weather complex working conditions.

[0122] The above are only exemplary embodiments of the present invention and are not intended to limit the scope of the present invention. Any equivalent changes and modifications made by any person skilled in the art without departing from the concept and principle of the present invention shall fall within the scope of protection of the present invention.

Claims

1. An automatic control system for emergency shutdown of an injection head, characterized in that: include: A load sensor is used to be arranged on the injection head, and can detect in real time the load pressure on the load sensor after the resultant force exerted on the coiled tubing in the well is transmitted to the injection head; A control circuit, the control circuit being used to connect with the injection head brake; A collection control module, the collection control module is electrically connected to the load sensor and the control circuit, and the collection control module can obtain the resultant force on the coiled tubing according to the load pressure detected by the load sensor; when the resultant force is less than a preset minimum weight value, or greater than a preset maximum weight value, or the change rate of the resultant force is greater than a preset maximum weight change rate, the collection control module can control the injection head pump to depressurize and stop, and control the injection head brake to brake after the injection head pump depressurizes and stops; A speed acquisition device, which can be used to detect the running speed of the coiled tube in real time, and the acquisition control module is electrically connected to the speed acquisition device; The acquisition control module controls the injection head pump to depressurize and stop only when the change rate of the resultant force is greater than the preset maximum weight change rate and the running speed of the coiled tubing detected by the speed acquisition device is greater than the preset minimum speed; the acquisition control module can control the injection head brake to brake through the control loop only after the injection head pump is depressurized and stops, and the running speed detected by the speed acquisition device is zero; Wherein, the control circuit is also used to connect with the injection head pump and the drum brake, the injection head pump is a hydraulically controlled proportional pump, and the control circuit includes a hydraulic oil main pipeline, a first hydraulic pipeline, a second hydraulic pipeline and a third hydraulic pipeline; an injection head manual brake control valve and an injection head brake control solenoid valve are sequentially arranged on the first hydraulic pipeline from its first end to its second end, a drum manual brake control valve is arranged on the second hydraulic pipeline, and a hydraulically controlled reversing valve, an injection head displacement control solenoid valve and a hydraulically controlled proportional direction control handle are sequentially arranged on the third hydraulic pipeline from its first end to its second end; The first end of the first hydraulic pipeline is connected to the outlet end of the hydraulic oil main pipeline, and the second end of the first hydraulic pipeline is used to connect to the injection head brake; the first end of the second hydraulic pipeline is connected to the outlet end of the hydraulic oil main pipeline, and the second end of the second hydraulic pipeline is used to connect to the drum brake; the first end of the third hydraulic pipeline is connected to the hydraulic oil main pipeline, the control oil port of the hydraulic control reversing valve is connected to the second hydraulic pipeline through the corresponding pipeline, and the connection point is located between the drum manual brake control valve and the second end of the second hydraulic pipeline, and the two output ports of the hydraulic control proportional direction control handle are respectively connected to the two hydraulic proportional control ports of the injection head pump; The acquisition control module can control the injection head displacement control solenoid valve to be energized so that the injection head pump can be depressurized and stopped; and can control the injection head brake control solenoid valve to be energized so that the injection head brake can be braked.

2. The automatic control system for emergency shutdown of the injection head according to claim 1, characterized in that: The load sensor is a bidirectional load sensor and is arranged on the box pressure rod of the injection head.

3. The automatic control system for emergency shutdown of the injection head according to claim 1, characterized in that: The speed acquisition device includes a speed encoder; The speed encoder is arranged on the passive sprocket of the injection head; or A friction wheel is arranged on the box of the injection head, on the guide pressing box of the injection head or on the roller for rolling the continuous tube. The friction wheel can be pressed on the surface of the continuous tube, and the speed encoder is arranged on the friction wheel.

4. The automatic control system for emergency shutdown of the injection head according to claim 1, characterized in that: The injection head emergency shutdown automatic control system also includes a timer. The acquisition control module is electrically connected to the timer and can control the injection head brake through the control loop only after the injection head pump is depressurized and stopped, and the timer has counted a preset time.

5. The automatic control system for emergency shutdown of the injection head according to claim 1, characterized in that: The injection head brake control solenoid valve and the injection head displacement control solenoid valve are both two-position three-way solenoid valves, and both have an oil inlet, a working port and an oil return port. When the two-position three-way solenoid valves corresponding to the injection head brake control solenoid valve and the injection head displacement control solenoid valve are in a de-energized state, the oil inlet is connected to the working port, and when they are in an energized state, the working port is connected to the oil return port.

6. The automatic control system for emergency shutdown of the injection head according to claim 1, characterized in that: A first pressure reducing valve is provided on the hydraulic oil main pipeline and between the first end of the third hydraulic pipeline and the outlet end of the hydraulic oil main pipeline, and a second pressure reducing valve and a third pressure reducing valve are provided in sequence on the third hydraulic pipeline and between the first end thereof and the hydraulic proportional direction control handle; A shuttle valve is connected in parallel to the hydraulic proportional directional control handle or a shuttle valve is integrated in the hydraulic proportional directional control handle, the two inlets of the shuttle valve are respectively connected to the two output ports of the hydraulic proportional directional control handle, and the outlet of the shuttle valve is connected to a pressure gauge.

7. The automatic control system for emergency shutdown of the injection head according to claim 1, characterized in that: The injection head emergency shutdown automatic control system also includes an electric proportional direction control handle and a potentiometer electrically connected to the acquisition control module, and the acquisition control module is also used to be electrically connected to the injection head pump, and the injection head pump is an electric proportional closed pump; The control circuit includes a hydraulic oil main pipeline and a first hydraulic pipeline, an injection head brake control solenoid valve is arranged on the first hydraulic pipeline, a first end of the first hydraulic pipeline is connected to the outlet end of the hydraulic oil main pipeline, and a second end of the first hydraulic pipeline is used to connect to the injection head brake; The acquisition control module can reset the electrical signal of the injection head pump to zero to relieve the pressure of the injection head pump and stop it; and can control the injection head brake to de-energize the solenoid valve to brake the injection head.

8. The automatic control system for emergency shutdown of the injection head according to claim 7, characterized in that: The control circuit further comprises a second hydraulic pipeline, on which a drum brake control solenoid valve is arranged, a first end of the second hydraulic pipeline is connected to an outlet end of the hydraulic oil main pipeline, and a second end of the second hydraulic pipeline is used to be connected to a drum brake; After the drum brake control solenoid valve is in the energized position, the acquisition control module can control the injection head pump to obtain the electrical signal.

9. The automatic control system for emergency shutdown of the injection head according to claim 8, characterized in that: The injection head brake control solenoid valve and the drum brake control solenoid valve are both two-position three-way solenoid valves, and both have an oil inlet, a working port and an oil return port, and when the two-position three-way solenoid valves corresponding to the injection head brake control solenoid valve and the drum brake control solenoid valve are in an electrical potential, the oil inlet is connected to the working port, and when they are in an electrical potential-free potential, the working port is connected to the oil return port; A first pressure reducing valve is provided on the hydraulic oil main pipeline, an injection head brake pressure sensor is connected on the first hydraulic pipeline and located between the injection head brake control solenoid valve and the second end of the first hydraulic pipeline, and a roller brake pressure sensor is connected on the second hydraulic pipeline and located between the roller brake control solenoid valve and the second end of the second hydraulic pipeline.

10. An automatic control method for emergency shutdown of an injection head, characterized in that: The injection head emergency stop automatic control method is implemented by the injection head emergency stop automatic control system according to any one of claims 1 to 9, and the injection head emergency stop automatic control method comprises the following steps: Setting a preset minimum weight value, a preset maximum weight value, and a preset maximum weight change rate; Real-time detection of the combined force on the coiled tubing in the well; Compare the resultant force with the preset minimum weight value and the preset maximum weight value, and compare the rate of change of the resultant force with the preset maximum weight change rate; when the resultant force is less than the preset minimum weight value, or greater than the preset maximum weight value, or the rate of change of the resultant force is greater than the preset maximum weight change rate, control the injection head pump to relieve pressure and stop, and control the injection head brake to brake after the injection head pump relieves pressure and stops.

11. The automatic control method for emergency shutdown of an injection head according to claim 10, characterized in that: The injection head emergency shutdown automatic control method also includes the following steps: Set a preset minimum speed; The running speed of the coiled tubing is detected in real time, and the injection head pump is controlled to relieve pressure and stop only when the change rate of the resultant force is greater than the preset maximum weight change rate and the detected running speed of the coiled tubing is greater than the preset minimum speed.

12. The automatic control method for emergency shutdown of an injection head according to claim 11, characterized in that: After the injection head pump stops rotating after depressurization, the injection head brake is controlled to brake only after a preset time is delayed or after it is detected that the running speed of the coiled tubing returns to zero.

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