Dynamic pressure compensation control method and device for electric packer

Abstract

The invention provides an electric packer dynamic pressure compensation control method and device.The method comprises the steps that first feedback pressure in a rubber sleeve is obtained in real time, the first feedback pressure is compared with a second threshold value, if the first feedback pressure is smaller than the second threshold value, the packer continues to conduct setting, and if the first feedback pressure is smaller than the second threshold value, the packer continues to conduct setting; and if the first feedback pressure is larger than or equal to the second threshold value, the packer enters a dynamic pressure compensation control mode. According to the invention, real-time monitoring and automatic compensation of the internal pressure of the rubber sleeve are realized, the dependence of manual operation is reduced, and the efficiency of underground operation is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of oil field production, and in particular relates to a dynamic pressure compensation control method and device for an electric packer. Background Art

[0002] The packer is a commonly used downhole oil production tool, which is often used for tubing and casing annulus isolation during downhole stratification testing, water finding, and water plugging operations. As a type of packer, the electric packer is driven by a motor to achieve setting or unsealing. It is easy to operate and effectively improves the efficiency of downhole operations. During the setting process of the electric packer, if the setting is unreliable, the packer will become loose, thus affecting the sealing effect. Therefore, it is of great significance to study the setting process control of the electric packer. At present, the control of the electric packer is mainly controlled by technicians based on experience after analyzing the data collected by downhole instruments. Therefore, the analysis cycle is long, and it is impossible to respond quickly to the situation during the setting process. There are also problems such as long control cycle, slow response speed, and substandard setting effect. Summary of the invention

[0003] In order to solve the above technical problems, the purpose of the present invention is to provide a dynamic pressure compensation control method and device for an electric packer, which can solve the problems of long control cycle, slow response speed and unsatisfactory sealing effect in the existing manual control method by real-time monitoring and automatic adjustment of the internal pressure of the rubber cylinder.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is as follows: First, the present invention provides a dynamic pressure compensation control method for an electric packer, the method comprising: Obtain the first feedback pressure inside the rubber cylinder in real time; The first feedback pressure is compared with a second threshold value. If the first feedback pressure is less than the second threshold value, the packer continues to seal; if the first feedback pressure is greater than or equal to the second threshold value, the packer enters a dynamic pressure compensation control mode.

[0005] The acquisition of the second threshold specifically includes: After receiving the command to start setting the seal, the current position pressure of the formation where the rubber cylinder is located is obtained; The current position pressure is added to the preset first threshold value of the packer setting as the second threshold value for completing the setting of the packer.

[0006] Further, the dynamic pressure compensation control mode is: The second feedback pressure inside the rubber cylinder is acquired in real time and a setting pressure compensation threshold is set; when the second feedback pressure is less than the setting pressure compensation threshold, the rubber cylinder is pressurized until the second feedback pressure is greater than or equal to the setting pressure compensation threshold, thus terminating the current pressure compensation and entering the dynamic pressure compensation control mode again.

[0007] Further, when the unblocking instruction is received, the dynamic pressure compensation control mode ends.

[0008] Further, the setting pressure compensation threshold is less than or equal to the second threshold.

[0009] Further, the setting pressure compensation threshold is 0.5 MPa less than the second threshold.

[0010] Secondly, the present invention also provides a dynamic pressure compensation control device for an electric packer, and applies a dynamic pressure compensation control method for an electric packer of the present invention. The device includes a pressure sensor, a single-chip microcomputer, a motor drive circuit and a screw nut mechanism. The pressure sensor is arranged inside the rubber cylinder, and the single-chip microcomputer, the motor drive circuit and the screw nut mechanism are arranged in the packer. The single-chip microcomputer is electrically connected to the motor drive circuit, and the motor drive circuit is electrically connected to the screw nut mechanism. One end of the screw nut mechanism is connected to a plunger pump. The pressure sensor is used to monitor the first feedback pressure or the current position pressure in real time; the single-chip microcomputer is used to compare the first feedback pressure with the second threshold value and output a control instruction to the motor drive circuit according to the comparison result, and the motor drive circuit controls the screw nut mechanism to drive the plunger pump to move so that the rubber cylinder seals the packer.

[0011] Furthermore, the pressure sensor is also used to monitor the second feedback pressure in real time; the single chip computer is also used to compare the second feedback pressure with the sealing pressure compensation threshold and output a control instruction to the motor drive circuit according to the comparison result, and the motor drive circuit controls the screw nut mechanism to drive the plunger pump to move and pressurize the rubber cylinder.

[0012] Furthermore, the screw-nut mechanism includes a motor, a screw, a stroke bracket, a nut, a forward stroke switch and a reverse stroke switch, wherein the forward stroke switch and the reverse stroke switch are used for steering control of the motor, the motor is electrically connected to the motor drive circuit, both ends of the screw are slidably nested in the stroke bracket, the output end of the motor is connected to one end of the screw, and the other end of the screw is slidably sleeved on the plunger pump; the nut is slidably embedded in the stroke bracket and sleeved on the screw, the reverse stroke switch and the forward stroke switch are respectively arranged at both ends of the stroke bracket, and the screw drives the nut to reciprocate to trigger the forward stroke switch or the reverse stroke switch.

[0013] Furthermore, the screw nut mechanism also includes an unsealing stroke switch. The rubber cylinder is provided with an unsealing valve. The unsealing stroke switch is arranged at the end of the stroke bracket close to one end of the plunger pump and is used to control the unsealing valve. The screw drives the nut to move to trigger the unsealing stroke switch.

[0014] The present invention adopts the above technical solution, which has the following advantages and effects: (1) The present invention provides a method and device for dynamic pressure compensation control of an electric packer. A pressure sensor is provided inside the packer to monitor the internal pressure of the rubber cartridge in real time. The internal pressure is compared with a set threshold value to achieve automatic compensation of the internal pressure of the rubber cartridge, thereby ensuring that the packer is sealed, reducing reliance on manual operation, and improving the efficiency of downhole operations.

[0015] (2) The present invention provides a method and device for dynamic pressure compensation control of an electric packer, which can timely track the changes in the internal pressure of the rubber cylinder after the sealing is completed, trigger automatic control to complete pressure compensation, and respond quickly to ensure that the packer is continuously and reliably sealed. In addition, during the sealing process of the packer, there is no need for ground personnel to analyze the internal pressure of the rubber cylinder of the packer and then manually control it, thereby reducing the problem of slow response speed caused by manual operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The present invention is a schematic flow chart of a dynamic pressure compensation control method for an electric packer.

[0017] Figure 2 It is a schematic diagram of the structure of the screw rod and nut mechanism of the present invention.

[0018] The reference numerals are as follows: 1-motor, 2-reverse travel switch, 3-travel bracket, 4-forward travel switch, 5-unsealing travel switch, 6-plunger pump, 7-screw, 8-nut. DETAILED DESCRIPTION

[0019] The embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings so that the purpose, features and advantages of the present invention can be more clearly understood. It should be understood that the embodiments shown in the accompanying drawings are not intended to limit the scope of the present invention, but are only intended to illustrate the essential spirit of the technical solution of the present invention.

[0020] like Figure 1 The present invention provides a method for controlling dynamic pressure compensation of an electric packer, comprising the following steps: Step S1, after the packer receives the instruction to start setting, the current position pressure of the formation where the rubber cylinder of the packer is located is obtained.

[0021] Specifically, a pressure sensor is installed inside the rubber tube of the packer, and the internal pressure of the rubber tube is monitored in real time through the pressure sensor. Before the packer is set, a plunger pump is used to extract well fluid, and the outlet of the plunger pump is connected to the inside of the rubber tube of the packer. At this time, the internal pressure of the rubber tube monitored by the pressure sensor is the current position pressure.

[0022] Since the packer is connected to the oil pipe, after moving downward to the specified depth, the ground controller sends a start setting command. After receiving the start setting command, the packer collects the current position pressure of the current downhole position through the pressure sensor set inside the rubber tube.

[0023] Step S2: The packer adds the current position pressure to the preset first threshold value of the packer setting as the second threshold value for the packer to complete the setting.

[0024] Specifically, the packer communicates with the ground controller via a single-core cable, and the ground controller can communicate with the host computer software after being connected to the computer using a USB cable. The host computer software can set the first threshold value for the packer to be set, and then the ground controller transmits the first threshold value to the microcontroller of the packer.

[0025] The single chip microcomputer adds the current position pressure to the first threshold value as the second threshold value for completing the setting of the packer. The second threshold value is automatically calculated by the single chip microcomputer and stored in the internal storage space of the single chip microcomputer.

[0026] Step S3, the single-chip microcomputer of the packer obtains the first feedback pressure inside the rubber cylinder in real time, and compares the first feedback pressure with the second threshold value. If the first feedback pressure is less than the second threshold value, the packer continues to set, and if the first feedback pressure is greater than or equal to the second threshold value, the packer completes setting. After the packer completes setting, the single-chip microcomputer marks the setting state of the packer, and the packer enters the dynamic pressure compensation control mode.

[0027] Specifically, when the packer starts to be set, the internal pressure of the rubber sleeve will change. At this time, the internal pressure of the rubber sleeve is monitored by the pressure sensor as the first feedback pressure.

[0028] Furthermore, in the dynamic pressure compensation control mode, a sealing pressure compensation threshold is pre-set in the single-chip microcomputer of the packer, and the second feedback pressure inside the rubber cylinder obtained in real time is compared with the sealing pressure compensation threshold. When the second feedback pressure is less than the sealing pressure compensation threshold, the single-chip microcomputer controls the rubber cylinder to pressurize until the second feedback pressure is greater than or equal to the sealing pressure compensation threshold, then stops pressurizing, ends this pressure compensation, and allows the packer to be sealed again and enter the dynamic pressure compensation control mode.

[0029] Specifically, since the packer is in use for at least tens of hours to several days, after the packer is set for the first time, the internal pressure of the rubber cylinder may decrease, affecting the setting effect. At this time, the internal pressure of the rubber cylinder is monitored by the pressure sensor as the second feedback pressure, and the dynamic pressure compensation control mode can improve the setting reliability of the packer.

[0030] In the dynamic pressure compensation control mode, the setting pressure compensation threshold can be set by the host computer software, and then the setting pressure compensation threshold is transmitted to the single chip computer of the packer by the ground controller. The setting pressure compensation threshold is less than or equal to the second threshold, preferably: the setting pressure compensation threshold is 0.5MPa less than the second threshold.

[0031] When the second feedback pressure inside the rubber cylinder is less than the setting pressure compensation threshold, the MCU will update the status of the packer to setting in real time, and send a pressure compensation command to control the rubber cylinder to pressurize. When the second feedback pressure is greater than or equal to the setting pressure compensation threshold, the MCU determines that the packer has been set again, stops pressurizing and marks the packer status as set completed. After the second setting is completed, the packer enters the dynamic pressure compensation control mode again.

[0032] Step S4, when unsealing the packer, an unsealing instruction is sent through the ground controller, and after receiving the unsealing instruction, the packer controls the rubber cylinder to unseal the packer, and the dynamic pressure compensation control mode ends.

[0033] Specifically, an unsealing valve is provided on the rubber cylinder. After receiving the unsealing instruction, the single-chip microcomputer of the packer controls the unsealing valve to open. At this time, the inside of the rubber cylinder is connected with the outside world, and the packer is unsealed.

[0034] like Figure 2 As shown. The present invention also provides a dynamic pressure compensation control device for an electric packer, and a dynamic pressure compensation control method for an electric packer using the present invention. The device includes a pressure sensor, a single chip microcomputer, a motor drive circuit, and a screw nut mechanism. The pressure sensor is arranged inside the rubber cylinder of the packer, and the single chip microcomputer, the motor drive circuit, and the screw nut mechanism are arranged inside the packer. The single chip microcomputer is electrically connected to the motor drive circuit, and the motor drive circuit is electrically connected to the screw nut mechanism. A plunger pump 6 is connected to one end of the screw nut mechanism. The pressure sensor is used to monitor the first feedback pressure, the second feedback pressure, or the current position pressure in real time. The single chip microcomputer is used to compare the first feedback pressure with the second threshold value and output a control instruction to the motor drive circuit according to the comparison result. The motor drive circuit drives the screw nut mechanism to control the plunger pump 6 to move so that the rubber cylinder is set to seal the packer.

[0035] At the same time, the single chip microcomputer is also used to compare the second feedback pressure with the setting pressure compensation threshold and output a control instruction to the motor drive circuit according to the comparison result, and the motor drive circuit controls the screw nut mechanism to drive the plunger pump 6 to pressurize the rubber cylinder. When the plunger pump 6 presses the rubber cylinder, the plunger pump 6 runs forward to inject the liquid inside the rubber cylinder to increase the internal pressure of the rubber cylinder to pressurize the rubber cylinder.

[0036] Further, the screw nut mechanism includes a motor 1, a screw 7, a travel bracket 3, a nut 8, a forward travel switch 4 and a reverse travel switch 2. The forward travel switch 4 and the reverse travel switch 2 are used to control the direction of the motor 1. The motor drive circuit is electrically connected to the motor 1. The two ends of the screw 7 are slidably nested in the travel bracket 3. The output end of the motor 1 is connected to one end of the screw 7. The other end of the screw 7 is slidably sleeved with a plunger pump 6. The nut 8 is slidably embedded in the travel bracket 3 and slidably sleeved on the outer periphery of the screw 7. The reverse travel switch 2 and the forward travel switch 4 are respectively arranged on the travel bracket 3 at both ends of the screw 7. The screw 7 drives the nut 8 to reciprocate to trigger the reverse travel switch 2 or the forward travel switch 4.

[0037] Specifically, the reverse stroke switch 2 is arranged at the end of the stroke bracket 3 near one end of the motor 1, and the forward stroke switch 4 is arranged at the end of the stroke bracket 3 near one end of the plunger pump 6. Since the packer is in the unsealing position when it is lowered into the well, when the packer starts to be set for the first time, the single-chip microcomputer outputs a driving signal to control the motor 1 to drive the screw rod 7 to rotate in the reverse direction, and the plunger pump 6 moves in the reverse direction to absorb the well fluid. When the screw rod 7 rotates and drives the nut 8 to move to the plunger pump 6 suction stroke position, the reverse stroke switch 2 will be triggered. At this time, the motor 1 reverses to drive the screw rod 7 to rotate forward, and the plunger pump 6 moves forward to inject liquid into the rubber cylinder. When the nut 8 touches the forward stroke switch 4, if the first feedback pressure inside the rubber cylinder does not reach the second threshold at this time, the single-chip microcomputer controls the motor 1 to rotate in the reverse direction. The above process is repeated until the first feedback pressure is greater than or equal to the second threshold. The single-chip microcomputer controls the motor 1 to stop running, and the packer is set.

[0038] In the dynamic pressure compensation control mode, the microcontroller controls the motor to operate in the same manner as the first setting process of the packer. When the microcontroller controls motor 1 to operate until the second feedback pressure inside the rubber cylinder is greater than or equal to the setting pressure compensation threshold, motor 1 stops running and the packer is set again.

[0039] Furthermore, the screw nut mechanism also includes an unsealing stroke switch 5, which is arranged at the end of the stroke bracket 3 near one end of the plunger pump 6 and is located on the outside of the forward stroke switch 4. The unsealing stroke switch 5 is used to control the unsealing valve of the rubber cylinder. When the packer is unsealed, after the single-chip microcomputer receives the unsealing instruction sent by the ground controller, the single-chip microcomputer outputs a driving signal to the motor driving circuit, and the motor driving circuit drives the motor 1 to rotate forward, and the screw 7 rotates to drive the nut 8 to generate a displacement to the nut 8 to trigger the unsealing stroke switch 5 at the unsealing position, and the unsealing valve is opened by the unsealing stroke switch 5 to unseal the packer.

Claims

1. A dynamic pressure compensation control method for an electric packer, characterized in that: The method comprises: Obtain the first feedback pressure inside the rubber cylinder in real time; The first feedback pressure is compared with a second threshold value. If the first feedback pressure is less than the second threshold value, the packer continues to seal; if the first feedback pressure is greater than or equal to the second threshold value, the packer enters a dynamic pressure compensation control mode.

2. The method for dynamic pressure compensation control of an electric packer according to claim 1, characterized in that: The acquisition of the second threshold specifically includes: After receiving the command to start setting the seal, the current position pressure of the formation where the rubber cylinder is located is obtained; The current position pressure is added to the preset first threshold value of the packer setting as the second threshold value for completing the setting of the packer.

3. A method for dynamic pressure compensation control of an electric packer according to claim 1 or 2, characterized in that: The dynamic pressure compensation control mode is: The second feedback pressure inside the rubber cylinder is acquired in real time and a setting pressure compensation threshold is set; when the second feedback pressure is less than the setting pressure compensation threshold, the rubber cylinder is pressurized until the second feedback pressure is greater than or equal to the setting pressure compensation threshold, thus terminating the current pressure compensation and entering the dynamic pressure compensation control mode again.

4. The method for dynamic pressure compensation control of an electric packer according to claim 3, characterized in that: When the unsealing instruction is received, the dynamic pressure compensation control mode ends.

5. The method for dynamic pressure compensation control of an electric packer according to claim 4, characterized in that: The setting pressure compensation threshold is less than or equal to the second threshold.

6. The method for dynamic pressure compensation control of an electric packer according to claim 5, characterized in that: The setting pressure compensation threshold is 0.5 MPa less than the second threshold.

7. An electric packer dynamic pressure compensation control device, using an electric packer dynamic pressure compensation control method as claimed in any one of claims 1 to 6, characterized in that: The device comprises a pressure sensor, a single chip microcomputer, a motor drive circuit and a screw nut mechanism. The pressure sensor is arranged inside the rubber cylinder. The single chip microcomputer, the motor drive circuit and the screw nut mechanism are arranged inside the packer. The single chip microcomputer is electrically connected to the motor drive circuit, and the motor drive circuit is electrically connected to the screw nut mechanism. One end of the screw nut mechanism is connected to a plunger pump (6). The pressure sensor is used to monitor a first feedback pressure or a current position pressure in real time. The single chip microcomputer is used to compare the first feedback pressure with a second threshold value and output a control instruction to the motor drive circuit according to the comparison result. The motor drive circuit controls the screw nut mechanism to drive the plunger pump (6) to move so that the rubber cylinder is sealed in the packer.

8. The dynamic pressure compensation control device for an electric packer according to claim 7, characterized in that: The pressure sensor is also used to monitor the second feedback pressure in real time; the single chip computer is also used to compare the second feedback pressure with the setting pressure compensation threshold and output a control instruction to the motor drive circuit according to the comparison result, and the motor drive circuit controls the screw nut mechanism to drive the plunger pump (6) to move and pressurize the rubber cylinder.

9. The dynamic pressure compensation control device for an electric packer according to claim 8, characterized in that: The screw-nut mechanism comprises a motor (1), a screw (7), a travel bracket (3), a nut (8), a forward travel switch (4) and a reverse travel switch (2), wherein the forward travel switch (4) and the reverse travel switch (2) are used for steering control of the motor (1), the motor (1) is electrically connected to the motor drive circuit, the two ends of the screw (7) are slidably embedded in the travel bracket (3), the output end of the motor (1) is connected to one end of the screw (7), the other end of the screw (7) is slidably sleeved on the plunger pump (6), the nut (8) is slidably embedded in the travel bracket (3) and sleeved on the screw (7), the reverse travel switch (2) and the forward travel switch (4) are respectively arranged at the two ends of the travel bracket (3), and the screw (7) drives the nut (8) to reciprocate to trigger the forward travel switch (4) or the reverse travel switch (2).

10. The dynamic pressure compensation control device for an electric packer according to claim 9, characterized in that: The screw nut mechanism also includes an unsealing stroke switch (5). The rubber cylinder is provided with an unsealing valve. The unsealing stroke switch (5) is arranged at the end of the stroke bracket (3) close to one end of the plunger pump (6) and is used to control the unsealing valve. The screw (7) drives the nut (8) to move and trigger the unsealing stroke switch (5).

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