Electric pump fracturing production integrated pipe string and implementation method thereof

Abstract

The present invention belongs to the technical field of oil well fracturing, and discloses an electric pump fracturing production integrated tubing and its implementation method. The electric pump fracturing production integrated tubing includes an oil pipe, a joint assembly, a production sleeve assembly, a tubing string packer and a bottom fracturing tubing. The joint assembly is provided with a main channel and a secondary channel, and the two ends of the main channel are respectively provided with a first port and a second port, and the secondary channel is provided with a third port. The oil pipe is connected to the first port. The joint assembly has at least a fracturing state and a production state. When in the fracturing state, the first port is connected to the second port, and the main channel and the secondary channel are not connected. When in the production state, the first port is connected to the secondary channel, and the first port and the second port are not connected. The production sleeve assembly is arranged between the second port and the bottom fracturing tubing, and is connected to the bottom fracturing tubing. The tubing string packer is located outside the bottom fracturing tubing. The present invention realizes efficient flowback and long-term production through integrated fracturing and production operations.

Description

Technical Field

[0001] The present invention relates to the technical field of offshore oil well exploitation, and in particular to an electric pump fracturing production integrated pipe string and an implementation method thereof. Background Art

[0002] At present, in the field of low-permeability oil and gas reservoir development, fracturing technology is the main technology in the development process. Generally, for fracturing operations, on-site construction mainly includes test fracturing, main fracturing and flowback. Among them, flowback is a very important link in fracturing operations. Whether the flowback is timely and efficient often directly determines the success or failure of fracturing. At present, the main methods of flowback are roughly self-flowing and artificial lifting. For normal pressure and low-pressure reservoirs, it is difficult to flow back by self-flowing due to insufficient energy of the formation's own flowback. Artificial lifting is often required. Artificial lifting mainly uses continuous tubing gas lift to achieve flowback without moving the pipe column, but the equipment requires a certain operating space, and it is difficult to operate on offshore platforms with narrow space, and this type of technology is difficult to achieve long-term continuous operation. However, as an offshore efficient artificial lifting technology that uses electric pumps, it is restricted by the fact that its pipe column cannot meet the needs of fracturing operations.

[0003] like Figure 1 The structure diagram of the common electric pump string is shown, which mainly includes common string oil pipe 1', common string safety valve 2', common string cable packer 3', common string annulus vent valve 4', common string hydraulic control pipeline 5', common string landing joint 6', common string check valve 7', common string centrifugal pump 8', common string separator 9', common string liquid inlet 10', common string protector 11', common string motor 12' and common string cable 13', and the whole string is inserted in the casing 100', and the bottom is located in the formation 200'. In the common electric pump string, due to the installation of the common string check valve 7', fluid cannot be injected through the common string oil pipe 1', and fracturing operation cannot be performed. However, if the setting of the ordinary tubing check valve 7' is cancelled, so that fluid can be injected into the ordinary tubing oil pipe 1', it is necessary to inject high-pressure, high-flow fracturing fluid containing proppant (quartz sand or ceramsite) into the ordinary tubing oil pipe 1' during fracturing, and the fracturing fluid must pass through the ordinary tubing centrifugal pump 8' and the ordinary tubing separator 9' before it can enter the formation 200'. In this process, the fracturing fluid will not only cause serious erosion to the impeller and guide wheel of the ordinary tubing centrifugal pump 8', causing it to be scrapped, but will also erode the ordinary tubing cable 13' and cause its insulation failure. Furthermore, the high pressure generated by the third pumping of the fracturing fluid will also directly act on the casing 100', and the casing has a relatively low pressure bearing capacity and is difficult to meet the fracturing requirements.

[0004] like Figure 2The structure diagram of the Y-type electric pump pipe string is shown. Similarly, the Y-type electric pump pipe string is installed with a Y-type joint, including a Y-type pipe string joint body 71', on which a Y-type pipe string first port 701', a Y-type pipe string second port 702' and a Y-type pipe string third port 703' are arranged, and a Y-type pipe string working cylinder 72' is arranged between the Y-type pipe string first port 701' and the Y-type pipe string second port 702', and a Y-type pipe string check valve 73' is arranged on the channel where the Y-type pipe string third port 703' is located. During normal production, a Y-type pipe string plug 13' needs to be used to be put into the Y-type pipe string working cylinder 72' and block the Y-type pipe string second port 702' to prevent the fluid from flowing back after the electric pump is pressurized. Therefore, the fluid enters the Y-type pipe string third port 703' under the action of the electric pump, and flows out of the Y-type pipe string first port 701' into the oil pipe to reach the wellhead. If the pipe string is used for fracturing, it is theoretically feasible to remove the Y-type pipe string plug 13', but during the fracturing process, the proppant in the fracturing fluid will accumulate on the Y-type pipe string check valve 73', which may cause the electric pump to be unable to lift the fluid during subsequent production operations, posing a certain risk. Furthermore, the Y-type pipe string joint body 71' is generally used in conjunction with a production sleeve. In the prior art, the opening of the production sleeve is mostly done by wire operation, which not only increases the overall workload, but also is inconvenient to operate.

[0005] Therefore, the existing technology cannot realize the more efficient return flow method of using electric pump string for fracturing and directly starting the electric pump for return flow after fracturing. Moreover, if the method of replacing the fracturing string with electric pump return flow after fracturing is adopted, there are many shortcomings: the return flow efficiency is low due to the long time of well repair, the cost of offshore well repair is high, and there is a risk of reservoir damage in the well repair process, which will affect the fracturing effect. Therefore, how to make full use of electric pumps to achieve efficient return flow and long-term production without affecting the fracturing effect is a problem that people in this field need to solve. Summary of the invention

[0006] The object of the present invention is to provide an electric pump fracturing production integrated pipe string and an implementation method thereof, so as to realize the fracturing production integrated operation and achieve the effects of efficient flowback and long-term production by using an electric pump.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] The integrated pipe string for electric pump fracturing production includes:

[0009] Oil pipes;

[0010] A joint assembly is provided with a main channel and a secondary channel, and the two ends of the main channel are respectively provided with a first port and a second port, the secondary channel is provided with a third port, the oil pipe is connected to the first port, and the joint assembly has at least a fracturing state and a production state. When in the fracturing state, the first port is connected to the second port, and the main channel and the secondary channel are not connected. When in the production state, the first port is connected to the secondary channel, and the first port and the second port are not connected.

[0011] A production sleeve assembly, a tubing packer and a bottom fracturing tubing, wherein the production sleeve assembly is disposed between the second port and the bottom fracturing tubing and connected to the bottom fracturing tubing, and the tubing packer is located outside the bottom fracturing tubing to seal the annulus between the casing and the bottom fracturing tubing.

[0012] As an option, the joint assembly includes a joint body and a movable sleeve, the main channel and the secondary channel are both arranged in the joint body, and the movable sleeve is arranged in the main channel and can cover the outlet of the secondary channel.

[0013] As an option, the movable sleeve includes a sleeve body and a first seal, and the first seal sleeve is arranged on the outside of the sleeve body and located between the sleeve body and the inner wall of the main channel.

[0014] Optionally, a plug is also included, which can push the movable sleeve to move in the main channel until the secondary channel is connected to the main channel and the second opening is blocked.

[0015] Optionally, the joint assembly further includes a one-flow valve, which is disposed on the secondary channel.

[0016] Optionally, the production sleeve assembly includes a sealing joint, a pressure relief joint and a production sleeve, and the production sleeve assembly has an open state and a closed state. When in the closed state, the production sleeve is sealed on the through hole of the sealing joint; when in the open state, the production sleeve is located at the bottom of the pressure relief joint.

[0017] Optionally, a soluble ball is also included, and the soluble ball can push the production sleeve from the sealing joint to the bottom of the pressure relief joint in the production sleeve.

[0018] Optionally, it also includes an electric pump unit and a cable. The electric pump unit is arranged at the entrance of the secondary channel. One end of the cable is electrically connected to the electric pump unit, and the other end is connected to the control system of the wellhead.

[0019] Optionally, the method further comprises a cable packer, which is located outside the oil pipe and seals the annulus between the casing and the oil pipe.

[0020] The implementation method of the electric pump fracturing production integrated tubing string includes:

[0021] The electric pump fracturing production integrated pipe string is lowered into a preset position in the casing;

[0022] Ensure that the joint assembly is in the fracturing state and the production sleeve assembly is in the closed state to carry out fracturing construction;

[0023] When adopting self-spraying production, keep the above state unchanged and continue production;

[0024] When artificial lift production is adopted, the soluble ball is put in to switch the closed state of the production sleeve assembly to the open state, the plug is put in to switch the fracturing state of the joint assembly to the production state, and the electric pump unit is started for production.

[0025] Beneficial effects of the present invention:

[0026] In the present invention, by setting the main channel and the secondary channel of the joint assembly, and setting the production sleeve assembly, the tubing string packer and the bottom fracturing string, the oil well fracturing and production operations of a single tubing string can be realized, and it is ensured that the operations of each other are not affected by each other. Specifically, the main channel of the joint assembly is provided with a first opening and a second opening, and the oil pipe is connected to the first opening to ensure smooth communication between the joint assembly and the oil pipe. Furthermore, the joint assembly has a fracturing state and a production state. In the fracturing state, the first port is connected to the second port, and the main channel is not connected to the secondary channel, so that the fracturing fluid can enter the bottom of the well in the main channel without polluting the secondary channel. Under the setting of the production sleeve assembly and the bottom fracturing string, the fracturing fluid can be accurately delivered to efficiently complete the fracturing operation, and its backflow operation can be realized in the main channel to avoid the residue of fracturing fluid in the secondary channel; in the production state, the first port is connected to the secondary channel, and the first port and the second port are not connected. In conjunction with the production sleeve assembly and the string packer, oil and gas cannot enter the bottom of the main channel, that is, oil and gas can only enter through the secondary channel and then be introduced into the oil pipe to achieve efficient production. This not only avoids the need to replace the string to improve operating efficiency, but also avoids damage to the internal components of the string by the fracturing fluid, thereby reducing engineering costs.

[0027] On the other hand, the present invention also provides an implementation method of an electric pump fracturing production integrated tubing, which can not only realize fracturing and production operations of the tubing separately and avoid the complicated operation of replacing the tubing, but also can arbitrarily switch the status of internal components of the tubing during self-flowing production or artificial lifting production to adapt to a variety of production situations, further improving the operation quality and efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the structure of a common electric pump string in the prior art described in an embodiment of the present invention;

[0029] Figure 2 It is a partial structural schematic diagram of a Y-type electric pump pipe string in the prior art described in an embodiment of the present invention;

[0030] Figure 3 It is a schematic diagram of the structure of the electric pump fracturing production integrated pipe string according to an embodiment of the present invention;

[0031] Figure 4 It is a structural schematic diagram of a first opening being connected to a second opening in an electric pump fracturing production integrated pipe string according to an embodiment of the present invention;

[0032] Figure 5 It is a schematic structural diagram of a plugger plugging between a first opening and a second opening in an electric pump fracturing production integrated pipe string according to an embodiment of the present invention;

[0033] Figure 6 It is a structural schematic diagram of a first port connected to a third port in an electric pump fracturing production integrated pipe string according to an embodiment of the present invention;

[0034] Figure 7 It is a partial cross-sectional view of a production sleeve assembly in an electric pump fracturing production integrated tubing string according to an embodiment of the present invention;

[0035] Figure 8 It is a partial cross-sectional view of the soluble ball-linked production sleeve in the electric pump fracturing production integrated pipe string according to an embodiment of the present invention when it moves to the bottom of the pressure relief joint.

[0036] In the figure:

[0037] 1'-common tubing; 2'-common tubing safety valve; 3'-common tubing cable packer; 4'-common tubing annulus vent valve; 5'-common tubing hydraulic control pipeline; 6'-common tubing landing joint; 7'-common tubing check valve; 8'-common tubing centrifugal pump; 9'-common tubing separator; 10'-common tubing liquid inlet; 11'-common tubing protector; 12'-common tubing motor; 13'-common tubing cable; 100'-casing; 200'-formation;

[0038] 701'-Y-type pipe string first port; 702'-Y-type pipe string second port; 703'-Y-type pipe string third port; 71'-Y-type pipe string joint body; 72'-Y-type pipe string working cylinder; 73'-Y-type pipe string check valve; 13'-Y-type pipe string plug;

[0039] 1-Oil pipe; 2-Safety valve; 3-Cable packer; 4-Annulus vent valve; 5-Hydraulic control pipeline; 6-Landing joint; 7-Joint assembly; 8-Electric pump unit; 9-Cable; 10-Production sleeve assembly; 11-Tube packer; 12-Bottom fracturing string; 13-Plug; 14-Soluble ball; 15-Oil casing annulus;

[0040] 701-first port; 702-second port; 703-third port; 71-connector body; 72-movable sleeve; 721-sleeve body; 722-first seal; 73-check valve;

[0041] 131-plug body; 132-second seal;

[0042] 101-sealing joint; 1011-through hole; 102-pressure relief joint; 103-production sleeve; 1031-first pressure relief hole; 1032-second pressure relief hole. DETAILED DESCRIPTION

[0043] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar parts or parts having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0044] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection, it can be a mechanical connection or an electrical connection, it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] In the description of the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include the first feature being in direct contact with the second feature, or may include the first feature being in contact with the second feature through another feature between them instead of being in direct contact. Moreover, a first feature being "above", "above" and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0046] At present, in the field of low-permeability oil and gas reservoir development, fracturing technology is the main technology in the development process. Generally, for fracturing operations, on-site construction mainly includes test fracturing, main fracturing and flowback. Among them, flowback is a very important link in fracturing operations. Whether the flowback is timely and efficient often directly determines the success or failure of fracturing. At present, the main methods of flowback are roughly self-flowing and artificial lifting. For normal pressure and low-pressure reservoirs, it is difficult to flow back by self-flowing due to insufficient energy of the formation's own flowback. Artificial lifting is often required. Artificial lifting mainly uses continuous tubing gas lift to achieve flowback without moving the pipe column, but the equipment requires a certain operating space, and it is difficult to operate on offshore platforms with narrow space, and this type of technology is difficult to achieve long-term continuous operation. However, as an offshore efficient artificial lifting technology that uses electric pumps, it is restricted by the fact that its pipe column cannot meet the needs of fracturing operations.

[0047] like Figure 1 The structure diagram of the common electric pump string is shown, which mainly includes common string oil pipe 1', common string safety valve 2', common string cable packer 3', common string annulus vent valve 4', common string hydraulic control pipeline 5', common string landing joint 6', common string check valve 7', common string centrifugal pump 8', common string separator 9', common string liquid inlet 10', common string protector 11', common string motor 12' and common string cable 13', and the whole string is inserted in the casing 100', and the bottom is located in the formation 200'. In the common electric pump string, due to the installation of the common string check valve 7', fluid cannot be injected through the common string oil pipe 1', and fracturing operation cannot be performed. However, if the setting of the ordinary tubing check valve 7' is cancelled, so that fluid can be injected into the ordinary tubing oil pipe 1', it is necessary to inject high-pressure, high-flow fracturing fluid containing a support agent (quartz sand or ceramsite) into the ordinary tubing oil pipe 1' during fracturing, and the fracturing fluid must pass through the ordinary tubing centrifugal pump 8' and the ordinary tubing separator 9' before it can enter the formation 200'. In this process, the fracturing fluid will not only cause serious erosion to the impeller and guide wheel of the ordinary tubing centrifugal pump 8', causing it to be scrapped, but will also erode the ordinary tubing cable 13' and cause its insulation failure. Furthermore, the high pressure generated by the third pumping of the fracturing fluid will also directly act on the casing 100', and the casing has a relatively low pressure bearing capacity and is difficult to meet the fracturing requirements.

[0048] like Figure 2The structure diagram of the Y-type electric pump pipe string is shown. Similarly, the Y-type electric pump pipe string is installed with a Y-type joint, including a Y-type pipe string joint body 71', on which a Y-type pipe string first port 701', a Y-type pipe string second port 702' and a Y-type pipe string third port 703' are arranged, and a Y-type pipe string working cylinder 72' is arranged between the Y-type pipe string first port 701' and the Y-type pipe string second port 702', and a Y-type pipe string check valve 73' is arranged on the channel where the Y-type pipe string third port 703' is located. During normal production, a Y-type pipe string plug 13' needs to be used to be put into the Y-type pipe string working cylinder 72' and block the Y-type pipe string second port 702' to prevent the fluid from flowing back after the electric pump is pressurized. Therefore, the fluid enters the Y-type pipe string third port 703' under the action of the electric pump, and flows out of the Y-type pipe string first port 701' into the oil pipe to reach the wellhead. If the pipe string is used for fracturing, it is theoretically feasible to remove the Y-type pipe string plug 13', but during the fracturing process, the proppant in the fracturing fluid will accumulate on the Y-type pipe string check valve 73', which may cause the electric pump to be unable to lift the fluid during subsequent production operations, and there is a certain risk. Furthermore, the Y-type pipe string joint body 71' is generally used in conjunction with the production sleeve. In the prior art, the opening of the production sleeve is mostly done by wire operation, which not only increases the overall workload, but also is inconvenient to operate.

[0049] Therefore, the existing technology cannot realize the more efficient return flow method of using electric pump string for fracturing and directly starting electric pump for return flow after fracturing. Moreover, if the method of replacing the fracturing string with electric pump return flow after fracturing is adopted, there are many shortcomings: the return flow efficiency is low due to the long time of well repair, the cost of offshore well repair is high, and there is a risk of reservoir damage in the well repair process, which will affect the fracturing effect. Therefore, how to make full use of electric pumps to achieve efficient return flow and long-term production without affecting the fracturing effect is a problem that people in this field need to solve.

[0050] The technical solution of this embodiment is further explained below with reference to the accompanying drawings and through specific implementation methods.

[0051] like Figure 3-Figure 8As shown, this embodiment provides an electric pump fracturing production integrated tubing string and an implementation method thereof. In this embodiment, the electric pump fracturing production integrated tubing includes an oil pipe 1, a joint assembly 7, a production sleeve assembly 10, a tubing string packer 11 and a bottom fracturing tubing string 12. The joint assembly 7 is provided with a main channel and a secondary channel, and the two ends of the main channel are respectively provided with a first port 701 and a second port 702. The oil pipe 1 is connected to the first port 701. The joint assembly 7 has at least a fracturing state and a production state. When in the fracturing state, the first port 701 is connected to the second port 702, and the main channel and the secondary channel are not connected. When in the production state, the first port 701 is connected to the secondary channel, and the first port 701 and the second port 702 are not connected. The production sleeve assembly 10 is arranged between the second port 702 and the bottom fracturing tubing string 12, and is connected to the bottom fracturing tubing string 12. The tubing string packer 11 is located outside the bottom fracturing tubing string 12 to seal the annulus between the casing and the bottom fracturing tubing string 12.

[0052] On the other hand, the implementation method of the electric pump fracturing production integrated tubing string includes:

[0053] The electric pump fracturing production integrated pipe string is lowered into the preset position in the casing; the joint assembly 7 is ensured to be in the fracturing state, and the production sleeve assembly 10 is in the closed state, and the fracturing construction is carried out; when the self-flowing production is adopted, the above state is maintained unchanged for production; when the artificial lifting production is adopted, the soluble ball 14 is put in to switch the closed state of the production sleeve assembly 10 to the open state, and the plug 13 is put in to switch the fracturing state of the joint assembly 7 to the production state, and the electric pump unit 8 is started for production.

[0054] Specifically, in this embodiment, by setting the main channel and the secondary channel of the joint assembly 7, and setting the production sleeve assembly 10, the tubing string packer 11 and the bottom fracturing string 12, the oil well fracturing and production operations of a single tubing string can be realized, and it is ensured that the operations are not affected by each other. Specifically, the main channel of the joint assembly 7 is provided with a first opening 701 and a second opening 702, and the oil pipe 1 is connected to the first opening 701 to ensure smooth communication between the joint assembly 7 and the oil pipe 1. Furthermore, the joint assembly 7 has a fracturing state and a production state. In the fracturing state, the first port 701 is connected to the second port 702, and the main channel and the secondary channel are not connected, so that the fracturing fluid can enter the bottom of the well in the main channel without polluting the secondary channel, and under the setting of the production sleeve assembly 10 and the bottom fracturing string 12, the fracturing fluid can be accurately delivered to efficiently complete the fracturing operation, and can realize its backflow operation in the main channel to avoid the residue of fracturing fluid in the secondary channel; in the production state, the first port 701 is connected to the secondary channel, and the first port 701 and the second port 702 are not connected, and the production sleeve assembly 10 and the string packer 11 are used to make it impossible for oil and gas to enter the bottom of the main channel, that is, oil and gas can only enter in the secondary channel and then be introduced into the oil pipe 1 to achieve efficient production. This not only avoids the need to replace the string to improve the operating efficiency, but also avoids the damage of the fracturing fluid to the internal components of the string, so as to reduce the engineering cost. On the other hand, this embodiment also provides an implementation method of an electric pump fracturing production integrated tubing string, which can not only realize fracturing and production operations on the tubing string separately and avoid the complicated operation of replacing the tubing string, but also can arbitrarily switch the status of the internal components of the tubing string during self-flowing production or artificial lift production to adapt to a variety of production situations, further improving the operation quality and efficiency.

[0055] The specific structure of the electric pump fracturing integrated tubing string in this embodiment is described below.

[0056] like Figure 3 As shown, the electric pump fracturing integrated tubing string in this embodiment includes an oil pipe 1, a safety valve 2, a cable packer 3, an annulus vent valve 4, a hydraulic control pipeline 5, a landing joint 6, a joint assembly 7, an electric pump unit 8, a cable 9, a production sleeve assembly 10, a tubing string packer 11, a bottom fracturing tubing string 12, a plug 13 and a soluble ball 14, and the annulus between the cable packer 3 and the tubing string packer 11 is set as an oil casing annulus 15.

[0057] Specifically, the oil pipe 1 is arranged in four sections and all are arranged in the casing, namely the first section of the oil pipe, the second section of the oil pipe, the third section of the oil pipe and the fourth section of the oil pipe. In this embodiment, one end of the first section of the oil pipe is arranged at the wellhead, and the other end is connected to the second section of the oil pipe through the safety valve 2. A landing joint 6 is arranged between the second section of the oil pipe and the third section of the oil pipe. The end of the third section of the oil pipe away from the second section of the oil pipe is connected to the joint assembly 7. The joint assembly 7 includes a main channel and a secondary channel. Its main channel is connected to the fourth section of the oil pipe, and its secondary channel is connected to the electric pump unit 8. The electric pump unit 8 is connected to the control system of the wellhead through the cable 9. Optionally, a production sleeve assembly 10 is connected between the fourth section of the oil pipe and the bottom fracturing string 12. Further, the cable packer 3 is located on the outside of the second section of the oil pipe to separate the safety valve 2 and the landing joint 6 on both sides and seal the annulus between the casing and the second section of the oil pipe. Optionally, the tubing packer 11 is located outside the bottom fracturing tubing 12 to seal the annulus between the casing and the bottom fracturing tubing 12, thereby setting the annulus between the cable packer 3 and the tubing packer 11 as the oil casing annulus 15 for subsequent production use.

[0058] Optionally, the setting of the safety valve 2 in this embodiment can timely block the oil pipe 1 under abnormal circumstances to prevent oil and gas from being sprayed from the oil pipe 1 to the outside of the wellhead, thereby avoiding safety risks during the operation. For example, the lower end of the first section of the oil pipe is connected to the upper joint of the safety valve 2 by a thread, and the lower joint of the safety valve 2 is connected to the upper section of the second section of the oil pipe by a thread. Further, the safety valve 2 is connected to the hydraulic control line 5, so that when the hydraulic control line 5 is depressurized, the safety valve 2 can be closed to block the first section of the oil pipe and the second section of the oil pipe; when the hydraulic control line 5 is pressurized, the safety valve 2 can be opened to keep the first section of the oil pipe and the second section of the oil pipe unobstructed, so that the hydraulic control line 5 can be used to control the unobstructed or blocked upper part of the oil pipe 1, avoiding safety problems and improving operation efficiency. In other embodiments, other measures can also be taken to control the opening and closing of the safety valve 2, which will not be repeated here.

[0059] like Figure 3As shown, the cable packer 3 is arranged on the outside of the second section of the oil pipe in the oil pipe 1, between the safety valve 2 and the landing joint 6, so as to seal the annulus between the casing and the oil pipe 1, and can protect the upper cable and other structures, and form the oil casing annulus 15 with the string packer 11. Specifically, the string packer 11 is provided with an annulus vent valve 4, and the annulus vent valve 4 is also connected to the hydraulic control pipeline 5, so that the annulus vent valve 4 can be driven to open and close under the control of the hydraulic control pipeline 5, and then the gas in the oil casing annulus 15 can be exported. Exemplarily, when the hydraulic control pipeline 5 applies pressure, the annulus vent valve 4 opens; when the hydraulic control pipeline 5 releases pressure, the annulus vent valve 4 closes. In other embodiments, the specific control relationship can be changed accordingly. Further, the safety valve 2 and the annulus vent valve 4 are both controlled by the hydraulic control pipeline 5, which can not only reduce the investment cost of the hydraulic control system, but also simplify its structure to enhance the reliability of the system.

[0060] like Figure 4-Figure 6 As shown, the joint assembly 7 in this embodiment includes a joint body 71, a movable sleeve 72 and a check valve 73, and the joint body 71 is provided with a first port 701, a second port 702 and a third port 703. Specifically, the main channel and the secondary channel of the joint body 71 are both provided on the joint body 71, and one end of the main channel facing the third section of the oil pipe is provided as the first port 701, and the other end thereof is provided as the second port 702, the inlet of the secondary channel is provided as the third port 703, and the outlet of the secondary channel is connected to the main channel and is located between the first port 701 and the second port 702. Exemplarily, the secondary channel is provided in an L-shape, the longer side of the secondary channel is provided in parallel with the main channel, and both are provided along the axial direction of the oil pipe 1, and the shorter side of the secondary channel is provided perpendicularly to the main channel and is connected to the main channel.

[0061] Furthermore, the third section of the oil pipe 1 is connected to the first port 701, and the fourth section of the oil pipe is connected to the second port 702, so as to form a passage of the oil pipe 1. Optionally, the electric pump unit 8 is arranged on the third port 703 at the entrance of the secondary channel, one end of the cable 9 is electrically connected to the electric pump unit 8, and the other end is connected to the control system of the wellhead, so that the start and stop of the electric pump unit 8 can be controlled at the wellhead, so as to pressurize the casing annulus 15 to realize artificial lift production.

[0062] Optionally, the joint assembly 7 in this embodiment has at least a fracturing state and a production state. When it is in the fracturing state, the first port 701 is connected to the second port 702, and the main channel is not connected to the secondary channel; when it is in the production state, the first port 701 is connected to the secondary channel, and the first port 701 and the second port 702 are not connected, so as to adapt to different working conditions of fracturing and production and avoid mutual influence between pipelines. Specifically, the movable sleeve 72 is arranged in the main channel and can be sealed at the outlet of the secondary channel to realize the connection and disconnection between the main channel and the secondary channel, thereby completing the switching setting between the fracturing state and the production state.

[0063] like Figure 4 As shown, specifically, the movable sleeve 72 includes a sleeve body 721 and a first seal 722, and the first seal 722 is sleeved on the outside of the sleeve body 721 and is located between the sleeve body 721 and the inner wall of the main channel. Exemplarily, when the movable sleeve 72 is in the initial position, it covers the outlet of the secondary channel and is fixed there by a shear pin or a shear ring, and two first seals 722 are provided, which are respectively located at the upper and lower positions of the outlet of the secondary channel, so that not only the sealing between the sleeve body 721 and the main channel can be ensured, but also the secondary channel can be sealed to prevent the residual part of the fluid from entering the secondary channel when the fluid passes through the main channel.

[0064] like Figure 5 and Figure 6 As shown, further, the plug 13 includes a plug body 131 and a second seal 132. Optionally, the second seal 132 is located below the plug body 131, and the plug body 131 can move in the main channel, push the movable sleeve 72 to move to the secondary channel to communicate with the main channel, and block at the second port 702. Exemplarily, after the plug 13 is put into the oil pipe 1, the plug 13 can move smoothly into the main channel and abut against the sleeve body 721, and the channel below the plug 13 is sealed by the second seal 132. Further, under the pressure difference effect after the wellhead is pressurized, the plug 13 can be linked to the movable sleeve 72 to cut off the shear pin or shear ring, thereby removing the restriction and moving to the bottom of the main channel, so that the outlet of the secondary channel is connected to the main channel, that is, the first port 701 can be connected to the third port 703, and the fluid can enter the oil pipe 1 through the secondary channel and the main channel in sequence from the third port 703 to complete the artificial lift operation.

[0065] Combination Figure 3-Figure 6As shown, the check valve 73 is arranged on the secondary channel to play a one-way flow guiding role. Specifically, the inlet of the check valve 73 is connected to the third port 703, and the outlet of the check valve 73 is connected to the outlet of the secondary channel, that is, the fluid in the secondary channel can only flow from the third port 703 to the outlet of the secondary channel, and this process is irreversible. Exemplarily, combined with the setting of the electric pump unit 8, oil and gas can enter from the third port 703 under the action of the electric pump unit 8, enter the main channel through the check valve 73 and the outlet of the secondary channel, and then flow through the first port 701 into the oil pipe 1 to achieve oil and gas production.

[0066] Generally speaking, when the movable sleeve 72 is in the initial position, the joint assembly 7 is in the fracturing state, and the fracturing fluid can be transported and returned through the main channel, so that the fracturing fluid can directly reach the formation, and will not enter the secondary channel to block the check valve 73, affecting the subsequent electric pump production operation. Similarly, when the movable sleeve 72 opens the outlet of the secondary channel under the linkage of the plug 13 and blocks the second port 702, the joint assembly 7 is in the production state, the secondary channel is connected to the main channel, and the oil and gas can be pumped to the wellhead under the action of the check valve 73 and the electric pump unit 8.

[0067] Combination Figure 3 , Figure 7 and Figure 8 As shown, the production sleeve assembly 10 is disposed between the second through port 702 and the bottom fracturing string 12, and its two ends are respectively connected to the fourth section of the oil pipe and the bottom fracturing string 12. Specifically, the production sleeve assembly 10 includes a sealing joint 101, a pressure relief joint 102 and a production sleeve 103, and the sealing joint 101 is provided with a through hole 1011, and the production sleeve 103 is provided with a first pressure relief hole 1031 and a second pressure relief hole 1032. Optionally, in this embodiment, the production sleeve assembly 10 has an open state and a closed state. When in the closed state, the production sleeve 103 is sealed on the through hole 1011 of the sealing joint 101, so that the through hole 1011 is isolated by the production sleeve 103, and the production sleeve assembly 10 is not connected to the casing annulus 15, thereby facilitating fracturing operations; when in the open state, the production sleeve 103 is located at the bottom of the pressure relief joint 102, so that the first pressure relief hole 1031 and the second pressure relief hole 1032 can be connected to the formation, thereby releasing the pressure into the formation, and opening the through hole 1011, so that the formation, the production sleeve assembly 10, and the casing annulus 15 are interconnected, so that oil and gas can enter the casing annulus 15 through the production sleeve assembly 10, thereby realizing production operations.

[0068] Optionally, in this embodiment, by dropping the soluble ball 14 and applying pressure difference at the wellhead, the soluble ball 14 pushes the production sleeve 103 from the sealing joint 101 to the bottom of the pressure relief joint 102 in the production sleeve 103, thereby realizing the switching of the closed state and the open state of the production sleeve assembly 10. The soluble ball 14 can be dissolved under the action of specific liquid materials, thereby avoiding the use and recovery of tools such as wire ropes, thereby improving the operating efficiency while ensuring the function of the production sleeve assembly 10.

[0069] like Figure 3 As shown, in this embodiment, the bottom fracturing string 12 is connected to the production sleeve assembly 10 and can extend into the formation, so that the fracturing fluid is transmitted to the bottom fracturing string 12 to achieve the fracturing operation. The specific fracturing method is not repeated here. Optionally, the string packer 11 is arranged outside the bottom fracturing string 12, and can be surrounded with the cable packer 3 to form an oil casing annulus 15, so that oil and gas cannot enter the oil casing annulus 15 at will, and the fracturing fluid will not corrode the cable 9 and other components in the oil casing annulus 15.

[0070] The following is a description of the implementation method of the electric pump fracturing production integrated tubing string in this embodiment.

[0071] The implementation method of the electric pump fracturing production integrated tubing in this embodiment includes lowering the electric pump fracturing production integrated tubing into a preset position in the casing; ensuring that the joint assembly 7 is in a fracturing state and the production sleeve assembly 10 is in a closed state, and performing fracturing construction; when self-flowing production is adopted, the above state is maintained unchanged for production; when artificial lifting production is adopted, the soluble ball 14 is put in to switch the closed state of the production sleeve assembly 10 to the open state, and the plug 13 is put in to switch the fracturing state of the joint assembly 7 to the production state, and the electric pump unit 8 is started for production. Specifically, during specific production operations, if the bottom hole pressure is sufficient, there is no need to put in the soluble ball 14 and the plug 13, and the main pipeline can be used to complete the self-flowing production; if the bottom hole pressure is insufficient and artificial pressurization is required, the soluble ball 14 and the plug 13 are put in order as described above, the production sleeve assembly 10 is opened, and the secondary channel and the main channel are connected, so that the oil and gas in the formation can enter the oil casing annulus 15, and enter the inlet of the check valve 73 of the secondary channel under the action of the electric pump unit 8, and flow out from the first port 701 into the oil pipe 1, so as to realize the oil production operation at the wellhead. For example, in this embodiment, the return operation can also be carried out by artificial lifting production. The specific method is the same as the production operation, which will not be repeated here.

[0072] Therefore, by using the electric pump fracturing and production integrated tubing string in this embodiment, fracturing and production operations can be completed in the same tubing string, saving the construction costs of replacing pipelines or well repairing in the prior art. The electric pump can be used to achieve efficient return production, which is beneficial to reducing the damage of fracturing fluid to the reservoir. There is no need to move the tubing string after fracturing, avoiding the damage of well washing to the reservoir, thereby completing efficient and high-quality fracturing and production operations.

[0073] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. An integrated pipe string for electric pump fracturing production, characterized in that: include: Oil pipe (1); A joint assembly (7) is provided with a main channel and a secondary channel, and the two ends of the main channel are respectively provided with a first opening (701) and a second opening (702), and the secondary channel is provided with a third opening (703); the oil pipe (1) is connected to the first opening (701), and the joint assembly (7) has at least a fracturing state and a production state. When in the fracturing state, the first opening (701) is connected to the second opening (702), and the main channel and the secondary channel are not connected; when in the production state, the first opening (701) is connected to the secondary channel, and the first opening (701) and the second opening (702) are not connected; A production sleeve assembly (10), a tubing packer (11) and a bottom fracturing tubing string (12), wherein the production sleeve assembly (10) is arranged between the second port (702) and the bottom fracturing tubing string (12) and is connected to the bottom fracturing tubing string (12), and the tubing packer (11) is located outside the bottom fracturing tubing string (12) and seals the annulus between the casing and the bottom fracturing tubing string (12); The joint assembly (7) comprises a joint body (71) and a movable sleeve (72); the main channel and the secondary channel are both arranged in the joint body (71); the movable sleeve (72) is arranged in the main channel and can cover the outlet of the secondary channel.

2. The electric pump fracturing production integrated pipe string according to claim 1, characterized in that: The movable sleeve (72) comprises a sleeve body (721) and a first seal (722), wherein the first seal (722) is sleeved on the outside of the sleeve body (721) and is located between the sleeve body (721) and the inner wall of the main channel.

3. The electric pump fracturing production integrated pipe string according to claim 1, characterized in that: It also includes a plug (13), wherein the plug (13) is capable of pushing the movable sleeve (72) to move in the main channel until the secondary channel is connected to the main channel and the second opening (702) is blocked.

4. The electric pump fracturing production integrated pipe string according to claim 1, characterized in that: The joint assembly (7) further comprises a check valve (73), wherein the check valve (73) is arranged on the secondary channel.

5. The electric pump fracturing production integrated tubing string according to any one of claims 1 to 4, characterized in that: The production sleeve assembly (10) comprises a sealing joint (101), a pressure relief joint (102) and a production sleeve (103). The production sleeve assembly (10) has an open state and a closed state. When in the closed state, the production sleeve (103) is sealed on the through hole (1011) of the sealing joint (101); when in the open state, the production sleeve (103) is located at the bottom of the pressure relief joint (102).

6. The electric pump fracturing production integrated pipe string according to claim 5, characterized in that: It also includes a soluble ball (14), wherein the soluble ball (14) can push the production sleeve (103) from the sealing joint (101) to the bottom of the pressure relief joint (102) in the production sleeve (103).

7. The electric pump fracturing production integrated tubing string according to any one of claims 1 to 4, characterized in that: It also includes an electric pump unit (8) and a cable (9), wherein the electric pump unit (8) is arranged at the entrance of the secondary channel, one end of the cable (9) is electrically connected to the electric pump unit (8), and the other end is connected to a control system at the wellhead.

8. The electric pump fracturing production integrated tubing string according to any one of claims 1 to 4, characterized in that: It also comprises a cable packer (3), which is located outside the oil pipe (1) and seals the annulus between the casing and the oil pipe (1).

9. The method for implementing the integrated pipe string for electric pump fracturing production is characterized in that: include: Lowering the electric pump fracturing production integrated pipe string according to any one of claims 1 to 8 into a preset position in the casing; Ensure that the joint assembly (7) is in a fracturing state and the production sleeve assembly (10) is in a closed state, and perform fracturing construction; When adopting self-spraying production, keep the above state unchanged and continue production; When artificial lifting production is adopted, the soluble ball (14) is put in to switch the closed state of the production sleeve assembly (10) to the open state, the plug (13) is put in to switch the fracturing state of the joint assembly (7) to the production state, and the electric pump unit (8) is started to carry out production.

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