Downhole pressure wave generation apparatus and method and applications

Abstract

The application relates to the field of offshore oilfield production, in particular to a downhole pressure wave generating device and method and application. The device comprises a device body, a central channel penetrating through the device body, a main channel in the device body and in communication with the central channel, a signal transmission unit in the device body, a switch arranged in the central channel and used for controlling injection liquid to be directly injected into a well along the central channel or controlling the injection liquid to be introduced into the main channel from the central channel, a pressure wave generating unit arranged at the lower part of the main channel and used for receiving injection liquid from the main channel to generate pressure waves, a control unit arranged at the upper part of the main channel and used for controlling the switch, and the signal transmission unit sends instructions to the control unit and the pressure wave generating unit through a control cable. Through the device, the downhole cableless intelligent water distributor can be controlled, the downhole working cylinder can be adjusted in real time, ground flow process reconstruction is not needed, and the device is especially suitable for offshore oilfield separate layer water injection.

Description

Technical Field

[0001] This invention relates to the field of offshore oilfield production, specifically to a downhole pressure wave generating device, method, and application. Background Technology

[0002] Currently, stratified water injection in offshore oilfields is a crucial method for maintaining formation pressure and improving ultimate recovery. With the development of intelligent oilfields, intelligent water injection technology has seen widespread advancements. Cableless stratified water injection technology involves installing a cableless intelligent water distributor in each layer. Pressure waves are generated by controlling the opening and closing of surface ball valves, thereby controlling the downhole cableless intelligent water distributor. This process features a simple tubing system and has been applied in multiple wells in offshore oilfields.

[0003] The regulation of downhole intelligent water distributors requires the use of pressure waves for control. Currently, the common method is to install an electric ball valve in the surface wellhead water injection pipeline, and control the opening and closing of the ball valve through a ground-based host computer to generate the required waveform for downhole control. For offshore oil fields, space for water injection pipelines is limited, and the modification process for surface water injection pipelines is time-consuming and difficult. Summary of the Invention

[0004] The purpose of this invention is to overcome the problems of limited space in oilfield water injection pipelines, long modification cycles and high difficulty in modifying surface water injection pipeline processes in existing technologies, and to provide a downhole pressure wave generating device, method and application. This device can avoid surface pipeline modification and improve wellhead utilization.

[0005] To achieve the above objectives, a first aspect of the present invention provides a downhole pressure wave generating device. The device includes a device body, a central channel penetrating the device body, a main channel communicating with the central channel within the device body, and a signal transmission unit within the device body. The central channel is equipped with a switch for controlling whether injection fluid is directly injected into the well along the central channel or whether injection fluid is introduced from the central channel into the main channel. A pressure wave generating unit is disposed at the lower part of the main channel to receive injection fluid from the main channel and generate pressure waves. A control unit is disposed at the upper part of the main channel to control the switch. The signal transmission unit sends commands to the control unit and the pressure wave generating unit via a control cable.

[0006] Preferably, the control unit includes a first motor and a first lead screw connected to the first motor, wherein the first motor is used to control the extension and retraction of the first lead screw.

[0007] Preferably, the main channel is provided with a main channel dynamic seal, and a cavity is formed in the upper part of the main channel; a first motor of the control unit is provided in the cavity; the first lead screw of the control unit passes through the main channel dynamic seal, and its end is connected to one end of the connecting rod by a pin.

[0008] Preferably, the other end of the connecting rod is fixedly connected to the switch, and the connecting rod is fixed by a rotating shaft.

[0009] Preferably, the switch is a sealed steel ball that can completely seal the central channel.

[0010] Preferably, the pressure wave generating unit includes a limiting cylinder, a second motor, and a second lead screw connected to the second motor. The second lead screw extends through the bottom of the limiting cylinder into the cavity of the limiting cylinder and cooperates with the sealing module to control the opening and closing of the upper opening of the limiting cylinder by elongation and shortening. The cavity of the limiting cylinder is connected to the downstream channel of the central channel switch.

[0011] Preferably, the second motor is located within the cavity formed by the limiting cylinder and the plug.

[0012] Preferably, the signal transmission unit includes a PCB circuit board and a cable connector that can be connected to an external controller of the device body.

[0013] A second aspect of the present invention provides a method for generating downhole pressure waves using the apparatus described herein. The method includes: an external controller connected to the device body via a cable connector sends an instruction to a signal transmission unit; the signal transmission unit transmits an action command to a control unit and a pressure wave generating unit based on the received instruction; the control unit controls the opening and closing of a central channel switch according to the received action command; when the central channel switch is closed, injection fluid flows from the central channel into the main channel; the pressure wave generating unit receives the injection fluid from the main channel and generates a pressure wave; and the downhole working barrel performs corresponding actions based on the received pressure wave signal.

[0014] Preferably, the method includes: an external controller connected to the device body sends instructions to a PCB circuit board, which then transmits action commands to the first and second motors via a control cable; the first motor controls the first lead screw to move up and down according to the received action commands, which in turn drives the connecting rod to move around the rotation axis, thereby controlling the movement of the sealing steel ball to complete the opening and closing of the central channel; when the central channel is closed, the sealing steel ball is in a state of blocking the central channel, and the injection fluid enters the main channel from the central channel; the second motor controls the second lead screw to move up and down according to the received action commands, and the continuous up and down movement of the second lead screw creates a gap with the sealing module, at which time the injection fluid is injected from the main channel through the gap pulsating injection limit cylinder cavity to generate pressure waves transmitted to the downhole, and the downhole working cylinder performs corresponding actions according to the received pressure wave signal.

[0015] The third aspect of the present invention provides an application of the device described in the first aspect in stratified water injection in offshore oil fields.

[0016] Through the above technical solution, the present invention has the following advantages:

[0017] The device of this invention is a pressure-controlled cableless water injection well downhole pressure wave generator. The pressure wave generator is installed inside the wellbore (it only needs to be placed below the tubing hanger, the installation method is simple and has good adaptability). The pressure wave generated by this device can realize the control of the downhole cableless intelligent water distributor, complete the real-time adjustment of the downhole working barrel, without the need for surface process modification, and without occupying wellhead space. It can be widely used in the precise control of the working barrel of water injection wells, and is especially suitable for stratified water injection in offshore oil fields. Attached Figure Description

[0018] Figure 1 This is a diagram of a conventional ground pressure wave generator tubing:

[0019] Figure 2 This is a diagram of the tubing string for the pressure-controlled cableless water injection downhole pressure wave generator of the present invention;

[0020] Figure 3 This is a schematic diagram of the pressure wave generator for cable-free water injection wells of the present invention not operating;

[0021] Figure 4 This is a schematic diagram of the operation of the pressure-controlled cableless water injection well pressure wave generator of the present invention.

[0022] Explanation of reference numerals in the attached figures

[0023] 1-Cable connector; 9-Rotating shaft;

[0024] 2-PCB circuit board; 10-Sealing steel ball;

[0025] 3-Device body; 11-Limiting cylinder;

[0026] 4-Control cable; 12-Sealed module;

[0027] 5 - First motor; 13 - Second lead screw;

[0028] 6 - First leadscrew; 14 - Second motor;

[0029] 7-Main channel dynamic seal; 15-Threaded plug;

[0030] 8-Connecting rod; 16-Center channel. Detailed Implementation

[0031] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0032] This invention provides a downhole pressure wave generator, comprising a device body, a central channel penetrating the device body, a main channel communicating with the central channel within the device body, and a signal transmission unit within the device body. The central channel is equipped with a switch for controlling the injection fluid to be injected directly into the well along the central channel, or for controlling the injection fluid to flow from the central channel into the main channel. A pressure wave generator unit is located at the lower part of the main channel to receive the injection fluid from the main channel and generate pressure waves. A control unit is located at the upper part of the main channel to control the switch. The signal transmission unit sends commands to the control unit and the pressure wave generator unit via a control cable.

[0033] The device of this invention is a pressure-controlled cableless water injection well downhole pressure wave generator. The pressure wave generator is installed inside the wellbore (it only needs to be placed below the tubing hanger, the installation method is simple and has good adaptability). The pressure wave generated by this device can realize the control of the downhole cableless intelligent water distributor, complete the real-time adjustment of the downhole working barrel, without the need for surface process modification, and without occupying wellhead space. It can be widely used in the precise control of the working barrel of water injection wells, and is especially suitable for stratified water injection in offshore oil fields.

[0034] According to a preferred embodiment of the present invention, the control unit includes a first motor and a first lead screw connected to the first motor, wherein the first motor is used to control the extension and retraction of the first lead screw.

[0035] According to a preferred embodiment of the present invention, the main channel is provided with a main channel dynamic seal, and a cavity is formed in the upper part of the main channel; a first motor of the control unit is provided in the cavity, and a first lead screw of the control unit passes through the main channel dynamic seal, and its end is connected to one end of a connecting rod by a pin.

[0036] According to a preferred embodiment of the present invention, the other end of the connecting rod is fixedly connected to the switch, and the connecting rod is fixed by a rotating shaft.

[0037] According to a preferred embodiment of the present invention, the switch is a sealed steel ball capable of completely sealing the central channel.

[0038] According to a preferred embodiment of the present invention, the pressure wave generating unit includes a limiting cylinder, a second motor, and a second lead screw connected to the second motor. The second lead screw extends through the bottom of the limiting cylinder into the cavity of the limiting cylinder and cooperates with the sealing module to control the opening and closing of the upper opening of the limiting cylinder by elongation and shortening. The cavity of the limiting cylinder is connected to the downstream channel of the central channel switch.

[0039] According to a preferred embodiment of the present invention, the second motor is located within the cavity formed by the limiting cylinder and the plug.

[0040] According to a preferred embodiment of the present invention, the signal transmission unit includes a PCB circuit board and a cable connector that can be connected to an external controller of the device body.

[0041] This invention provides a downhole pressure wave generation method using the device described herein. The method includes: an external controller connected to the device body via a cable connector sends a command to a signal transmission unit; the signal transmission unit then transmits an action command to a control unit and a pressure wave generation unit based on the received command; the control unit controls the opening and closing of a central channel switch according to the received action command; when the central channel switch is closed, injection fluid flows from the central channel into the main channel; the pressure wave generation unit receives the injection fluid from the main channel and generates a pressure wave; and the downhole working barrel performs corresponding actions based on the received pressure wave signal.

[0042] According to a preferred embodiment of the present invention, the method includes: an external controller connected to the device body via a cable connector sends an instruction to a PCB circuit board; the PCB circuit board, upon receiving the instruction, transmits an action command via a control cable to a first motor and a second motor; the first motor controls a first lead screw to move up and down according to the received action command; when the first lead screw moves, it drives a connecting rod to move around a rotation axis, thereby controlling the movement of a sealing steel ball to complete the opening and closing of the central channel; when the central channel is closed, the sealing steel ball is in a state of blocking the central channel, and the injection fluid enters the main channel from the central channel; the second motor controls a second lead screw to move up and down according to the received action command; through the continuous up and down movement of the second lead screw, a gap is created between the second lead screw and the sealing module; at this time, the injection fluid is injected from the main channel through the gap pulsating injection limiting cylinder cavity to generate a pressure wave transmitted to the downhole; the downhole working cylinder then performs corresponding actions according to the received pressure wave signal.

[0043] This invention provides an application of the aforementioned device in stratified water injection in offshore oil fields.

[0044] The present invention will now be described in detail with reference to the accompanying drawings.

[0045] refer to Figure 3-4The present invention provides a downhole pressure wave generating device, which includes a device body 3, a central channel 16 penetrating the device body, a main channel communicating with the central channel 16 inside the device body 3, and a PCB circuit board 2 inside the device body.

[0046] The central channel 16 is equipped with a sealing steel ball that can completely seal the central channel, which is used to control the injection fluid to be injected directly into the well along the central channel 16, or to control the injection fluid to be introduced into the main channel from the central channel 16.

[0047] A pressure wave generating unit is provided at the lower part of the main channel to receive the injected liquid from the main channel and generate pressure waves. The pressure wave generating unit includes a limiting cylinder 11, a second motor 14, and a second lead screw 13 connected to the second motor. The second lead screw 13 extends through the bottom of the limiting cylinder 11 into the cavity of the limiting cylinder and cooperates with the sealing module 12 to control the opening and closing of the upper opening of the limiting cylinder 11 by extending and shortening. The cavity of the limiting cylinder is connected to the downstream channel of the switch on the central channel. A plug is provided at the lower end of the limiting cylinder so that the second motor is located in the cavity formed by the limiting cylinder and the plug.

[0048] A control unit for controlling the switch is provided at the upper part of the main channel. The control unit includes a first motor 5 and a first lead screw 6 connected to the first motor 5. The first motor 5 is used to control the extension and retraction of the first lead screw 6. The main channel is provided with a main channel dynamic seal 7, forming a cavity at the upper part of the main channel. The first motor 5 of the control unit is provided in the cavity. The first lead screw 6 passes through the main channel dynamic seal 7, and its end is connected to one end of a connecting rod 8 by a pin. The other end of the connecting rod 8 is fixedly connected to a sealing steel ball, and the connecting rod 8 is fixed by a rotating shaft 9.

[0049] The PCB circuit board 2 sends commands to the first motor and the second motor via the control cable 4, further controlling the extension and retraction of the first lead screw and the second lead screw. The PCB circuit board 2 is connected to the external controller of the device body via the cable connector 1.

[0050] In the device of this invention, the external controller of the device body connected to the cable connector 1 sends instructions to the PCB circuit board 2. The PCB circuit board 2 transmits the action commands to the first motor 5 and the second motor 14 through the control cable according to the received instructions. The first motor 5 controls the first lead screw 6 to move up and down according to the received action commands. When the first lead screw 6 moves, it drives the connecting rod 8 to move around the rotation axis 9, thereby controlling the movement of the sealing steel ball to complete the opening and closing of the central channel 16. When the central channel 16 is closed, the sealing steel ball is in the state of blocking the central channel, and the injection fluid enters the main channel from the central channel 16. The second motor 14 controls the second lead screw 13 to move up and down according to the received action commands. The second lead screw 13 continuously moves up and down and creates a gap with the sealing module 12. At this time, the injection fluid is injected from the main channel through the gap pulsating injection limit cylinder cavity to generate pressure waves and transmit them to the well. The well working cylinder then performs corresponding actions according to the received pressure wave signals.

[0051] like Figure 2 The downhole pressure wave generator of the present invention is used for stratified water injection in offshore oil fields. In the tubing string, the device body (3) is connected to the bottom of the tubing hanger through the tubing buckle. The cable connector 1 is connected to the armored signal cable and the lower part is connected to the control cable 4. The armored signal cable extends upward to the wellhead and is connected to the portable ground controller at the wellhead. The portable ground controller is connected to the control computer at the wellhead.

[0052] Compared to adopting Figure 1 The conventional surface pressure wave generator string shown is used for water injection. The device of the present invention can complete the real-time adjustment of the downhole working tube, does not require surface process modification, and does not occupy wellhead space. It can be widely used in the precise control of the working tube of water injection wells.

[0053] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A downhole pressure wave generating device, characterized in that, This device is used for stratified water injection in offshore oil fields. The device includes a device body, a central channel running through the device body, a main channel inside the device body that communicates with the central channel, and a signal transmission unit inside the device body. The device body is connected to the bottom of the oil pipe hanger via an oil pipe fastener. The central channel is equipped with a switch to control the injection fluid to be injected directly into the well along the central channel, or to control the injection fluid to be introduced from the central channel into the main channel; A pressure wave generating unit is provided at the lower part of the main channel to receive pressure waves from the injected liquid in the main channel. The main channel is equipped with a main channel dynamic seal, forming a cavity in the upper part of the main channel; The cavity is equipped with a first motor for the control unit; The first lead screw of the control unit passes through the main channel dynamic seal, and its end is connected to one end of the connecting rod by a pin; the other end of the connecting rod is fixedly connected to the switch, and the connecting rod is fixed by a rotating shaft; the switch is a sealing steel ball that can completely seal the central channel; A control unit for controlling the switch is provided at the upper part of the main channel. The control unit includes a first motor and a first lead screw connected to the first motor. The signal transmission unit sends commands to the control unit and the pressure wave generating unit via a control cable; The signal transmission unit includes a PCB circuit board and a cable connector that can be connected to an external controller of the device body. The upper part of the cable connector is connected to an armored signal cable, and the lower part is connected to a control cable. The armored signal cable extends upward to the wellhead and is connected to a portable ground controller at the wellhead. The portable ground controller at the wellhead is connected to a control computer at the wellhead. When the switch of the central channel is closed, the injection fluid flows from the central channel into the main channel. The pressure wave generating unit receives the injection fluid from the main channel and generates a pressure wave. The downhole working barrel then performs corresponding actions based on the received pressure wave signal. The pressure wave generating unit includes a limiting cylinder, a second motor, and a second lead screw connected to the second motor. The second lead screw extends through the bottom of the limiting cylinder into the cavity of the limiting cylinder and cooperates with the sealing module to control the opening and closing of the upper opening of the limiting cylinder by extending and shortening. The cavity of the limiting cylinder is connected to the downstream channel of the central channel switch. A plug is provided at the lower end of the limiting cylinder so that the second motor is located in the cavity formed by the limiting cylinder and the plug. When the central channel is closed, the injection fluid flows from the central channel into the main channel. The second motor will control the second lead screw to move up and down according to the received action command. The continuous up and down movement of the second lead screw creates a gap with the sealing module. At this time, the injection fluid is injected from the main channel into the cavity of the gap pulsating injection limiting cylinder to generate pressure waves and transmit them to the downhole. The downhole working cylinder then performs corresponding actions according to the received pressure wave signal.

2. The apparatus according to claim 1, wherein, The first motor is used to control the extension and retraction of the first lead screw.

3. The apparatus according to claim 1 or 2, wherein, The first motor controls the first lead screw to move up and down according to the received action command. When the first lead screw moves, it will drive the connecting rod to move around the rotation axis, thereby controlling the movement of the sealing steel ball to complete the opening and closing of the central channel.

4. A method for generating downhole pressure waves, characterized in that, Using the apparatus according to any one of claims 1-3, the method comprises: The external controller of the device body connected to the cable connector sends instructions to the signal transmission unit, which then transmits action commands to the control unit and the pressure wave generating unit based on the received instructions. The control unit will control the opening and closing of the central channel switch according to the received action commands; When the switch of the central channel is closed, the injection fluid flows from the central channel into the main channel. The pressure wave generating unit receives the injection fluid from the main channel and generates a pressure wave. The downhole working barrel then performs corresponding actions based on the received pressure wave signal. Among them, the external controller of the device body connected to the cable connector sends instructions to the PCB circuit board, and the PCB circuit board transmits the action commands to the first motor and the second motor through the control cable according to the received instructions; The first motor will control the first lead screw to move up and down according to the received action command. When the first lead screw moves, it will drive the connecting rod to move around the rotation axis, thereby controlling the movement of the sealing steel ball to complete the opening and closing of the central channel. When the central channel is closed, the sealing steel ball is in the state of blocking the central channel. The injection fluid enters the main channel from the central channel. The second motor will control the second lead screw to move up and down according to the received action command. The continuous up and down movement of the second lead screw creates a gap with the sealing module. At this time, the injection fluid is injected from the main channel through the gap pulsating injection limit cylinder cavity to generate pressure waves and transmit them to the downhole. The downhole working cylinder then performs corresponding actions according to the received pressure wave signal.

5. The application of the device according to any one of claims 1-3 in stratified water injection in offshore oil fields.

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