Casting and fishing electric pump anti-airlock fracturing production integrated pipe column and operation method

Abstract

The invention discloses an anti-airlock fracturing production integrated tubular column of a throwing and fishing electric pump and an operation method. The device comprises an outer sleeve; the tie-back barrel, the drilling liner hanger and the lower inner sleeve are sequentially connected from top to bottom; a differential pressure sliding sleeve is arranged at the toe end of the lower inner sleeve; the upper inner casing pipe is sequentially provided with a large-drift-diameter hydraulic control sliding sleeve, a deep well large-drift-diameter subsurface safety valve, a large-drift-diameter hydraulic control stratum isolation valve, a tie-back casing pipe anchor and an insertion seal from top to bottom. A plurality of bridge plugs are pumped into the lower inner casing pipe in batches through the upper inner casing pipe and used for conducting clustering perforation fracturing operation; the electric pump pipe column is sequentially provided with a composite pipe cable, a production packer and an electric pump unit from top to bottom; the electric pump pipe column is arranged in the inner upper casing pipe through the composite pipe cable, and the production packer is located above the large-drift-diameter hydraulic control sliding sleeve. The device has the beneficial effects that multi-layer-section separate layer fracturing of one pipe column can be achieved, after fracturing, the pipe column is immovable, manual lifting is rapidly conducted, and the phenomenon that a well killing fluid pollutes a reservoir is prevented.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas well engineering, and particularly relates to a fishing and electric pump anti-gas-lock fracturing production integrated string and an operation method thereof. Background Art

[0002] With the continuous development of offshore oil and gas resources, more and more reserves have been put into use. Therefore, research on enhancing the production rate of low-permeability reserves and improving the development effect of low-permeability oil reservoirs is particularly urgent. According to technical research at home and abroad, the large-scale fracturing technology is still the mainstream means to solve the problems of low production and low efficiency in offshore low-permeability reservoirs. However, there are still two major technical problems that need to be solved in the current traditional fracturing production operation methods: First, the pipe string needs to be tripped in and out multiple times during the construction process, generally 3-5 times, and the construction time is long; Second, the pipe string needs to be washed and pressured during tripping in and out, which causes secondary pollution to the reservoir and seriously affects the fracturing production effect; Third, the existing fracturing production integrated string can only fracture in the tubing and cannot directly fracture in the casing, resulting in a low construction displacement.

[0003] In view of this, an integrated string and an operation method for fishing and electric pump anti-gas-lock fracturing production are urgently needed in offshore oilfields to solve the above problems. Summary of the Invention

[0004] The purpose of the present invention is to provide a fishing and electric pump anti-gas-lock fracturing production integrated string, which is provided with an outer casing, a tie-back cylinder, a liner hanger, a lower inner casing, an upper inner casing, a large-diameter hydraulic sliding sleeve, a deep-well large-diameter downhole safety valve, a large-diameter hydraulic formation isolation valve, a tie-back casing anchor, an insert seal, a plurality of bridge plugs and an electric pump string, and can realize multi-stage layered fracturing with one trip of the string, quickly switch to artificial lift production without moving the string after fracturing, and prevent the reservoir from being polluted by the kill fluid.

[0005] The purpose of the present invention is to provide an operation method for a fishing and electric pump anti-gas-lock fracturing production integrated string, which can realize multi-stage layered fracturing with one trip of the string, quickly switch to artificial lift production without moving the string after fracturing, and prevent the reservoir from being polluted by the kill fluid.

[0006] To achieve the above purpose, the present invention adopts the following technical solutions, including:

[0007] The outer casing is run in after the wellbore is drilled and cemented in the well.

[0008] The tie-back cylinder, the liner hanger and the lower inner casing are connected in sequence from top to bottom, are used to be run into the outer casing, are suspended at the lower end of the outer casing through the liner hanger, and are set, released and cemented; a differential pressure sliding sleeve is provided at the toe end of the lower inner casing.

[0009] The upper inner casing is successively provided with a large-diameter hydraulic sliding sleeve, a deep-well large-diameter downhole safety valve, a large-diameter hydraulic formation isolation valve, a tie-back casing anchor and an insertion seal from top to bottom; after the outer casing is lowered, the insertion seal arranged at the lower end of the upper inner casing is used to cooperate with the tie-back cylinder to achieve sealing and positioning, so as to realize the butt joint of the upper inner casing and the lower inner casing;

[0010] A plurality of bridge plugs are respectively pumped into the lower inner casing in batches through the upper inner casing and are used for cluster perforation and fracturing operations respectively; the electric pump string is successively provided with a composite cable, a production packer and an electric pump unit from top to bottom; the electric pump string is lowered into the upper inner casing through the composite cable, and the production packer is located above the large-diameter hydraulic sliding sleeve; the electric pump string is used for auxiliary flowback and production;

[0011] Wherein, the large-diameter hydraulic sliding sleeve, the deep-well large-diameter downhole safety valve and the large-diameter hydraulic formation isolation valve are respectively connected with a first hydraulic control pipeline, a second hydraulic control pipeline and a third hydraulic control pipeline for real-time opening and closing; the inner diameters of the large-diameter hydraulic sliding sleeve, the deep-well large-diameter downhole safety valve, the large-diameter hydraulic formation isolation valve, the tie-back casing anchor, the insertion seal, the tie-back cylinder and the liner hanger are all larger than those of the bridge plugs.

[0012] Preferably, the outer diameters of the upper inner casing and the lower inner casing are 5.5 inches; the outer diameter of the outer casing is 9.625 inches.

[0013] Preferably, the inner diameter of the large-diameter hydraulic sliding sleeve is consistent with that of the tie-back casing anchor, and the maximum internal pressure borne by the large-diameter hydraulic sliding sleeve is 10,000 psi.

[0014] Preferably, the inner diameter of the deep-well large-diameter downhole safety valve is consistent with that of the upper inner casing, which can meet the requirement of a depth of 3,000 m, and the maximum internal pressure borne is 10,000 psi.

[0015] Preferably, the inner diameter of the large-diameter hydraulic formation isolation valve is consistent with that of the tie-back casing anchor, which can meet the requirement of a depth of 3,000 m, and the maximum internal pressure borne is 10,000 psi.

[0016] A method for an integrated string operation of fishing electric pump anti-gas-lock fracturing production, which applies the integrated string of fishing electric pump anti-gas-lock fracturing production described in any one of the above, includes the following steps:

[0017] Step 1: Connect the tie-back cylinder, the liner hanger and the lower inner casing in sequence from top to bottom, lower them into the outer casing, and hang them in the outer casing through the liner hanger, and then set, release and cement;

[0018] Step 2: A large-diameter hydraulic sliding sleeve, a deep-well large-diameter downhole safety valve, a large-diameter hydraulic formation isolation valve, a tie-back casing anchor and an insert seal are successively arranged on the upper inner casing from top to bottom; the upper inner casing is lowered into the outer casing; the seal and positioning are realized by the cooperation of the insert seal arranged at the lower end of the upper inner casing and the tie-back cylinder, thereby realizing the docking of the upper inner casing and the lower inner casing.

[0019] Step 3: Pressurize the upper inner casing after successful docking to open the differential pressure sliding sleeve, so that the lower inner casing is communicated with the formation, connect the perforating gun with the bridge plug; electrically connect the staged ignition device with the perforating gun and the bridge plug respectively; then the perforating gun and the bridge plug are lowered into the lower inner casing through the upper inner casing by means of pumping, and then the bridge plug is set and released by the staged ignition device, the perforating gun is lifted to the upper perforating position, and then perforation operations are carried out by the staged ignition device. After the perforation operation is completed, the perforating gun is withdrawn, and only the bridge plug remains at the bottom of the well.

[0020] Step 4: Inject fracturing fluid into the upper inner casing, the fracturing fluid enters the lower inner casing from the upper inner casing, and enters the formation through the perforation holes to realize the volume fracturing operation of the lowest layer.

[0021] Step 5: Connect another bridge plug with the perforating gun and lower it into the lower inner casing by means of pumping, and realize the setting of the bridge plug, the perforation of the perforation section and the volume fracturing according to the operation methods in Step 3 and Step 4; this step is repeated for the fracturing of the third stage and above.

[0022] Step 6: After the last stage of fracturing is completed, close the large-diameter hydraulic formation isolation valve through the third hydraulic control pipeline. Under the condition of pressure-holding and non-kill well, the electric pump string is successively provided with a composite cable, a production packer and an electric pump unit from top to bottom; the electric pump string is lowered into the upper inner casing through the composite cable, and the production packer is set above the large-diameter hydraulic sliding sleeve through the hydraulic control pipeline in the composite cable.

[0023] Step 7: Open the large-diameter hydraulic formation isolation valve through the third hydraulic control pipeline, and confirm that the deep-well large-diameter downhole safety valve is in the open state; start the electric pump unit for auxiliary flowback and production, and the electric pump string extracts the produced oil from the annulus between the composite cable and the upper inner casing; if the produced fluid contains a high content of gas, the large-diameter hydraulic sliding sleeve can be opened at any time through the first hydraulic control pipeline for gas exhaust to prevent the electric pump unit from being gas-locked.

[0024] Preferably, when reverse well flushing is required, the large-diameter hydraulic sliding sleeve and the large-diameter hydraulic formation isolation valve are respectively in the open and closed states through the first hydraulic control pipeline and the third hydraulic control pipeline for well flushing circulation, and the large-diameter hydraulic formation isolation valve can prevent the well flushing fluid from entering the formation and polluting the reservoir.

[0025] Preferably, when a pump inspection is required, first close the large-bore hydraulic formation isolation valve and the deep-well large-bore downhole safety valve through the third hydraulic control pipeline and the second hydraulic control pipeline respectively, then release the production packer through the composite cable, retrieve the production packer and the electric pump unit through the composite cable, and then complete the installation of the new production packer and the electric pump unit through the composite cable.

[0026] Preferably, when the upper inner casing needs to be retrieved later, first open the large-bore hydraulic sliding sleeve through the first hydraulic control pipeline, inject kill fluid into the annulus between the upper inner casing and the outer casing, and the kill fluid enters the upper inner casing through the large-bore hydraulic sliding sleeve to achieve well killing. After successful well killing, lift the upper inner casing and retrieve it from the wellhead.

[0027] Preferably, in step six, the pressure of the pressurized fluid is not higher than the pressure-bearing capacity of the composite cable.

[0028] The beneficial effects of the present invention are as follows: it can achieve multi-stage layered fracturing with a single string of pipes, quickly switch to artificial lift production without moving the pipe string after fracturing, and prevent the kill fluid from contaminating the reservoir. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of an integrated pipe string for fishing electric pump, preventing gas lock and fracturing production according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0030] The following further describes the invention in detail with reference to the drawings, so that those skilled in the art can implement it according to the description in the specification.

[0031] It should be understood that the terms such as "having", "comprising" and "including" used herein do not exclude the presence or addition of one or other elements or their combinations.

[0032] As Figure 1 shown, an integrated pipe string 1 for fishing electric pump, preventing gas lock and fracturing production according to the present invention and its operation method include: an outer casing 110, which is lowered and cemented in the well after the wellbore is drilled;

[0033] A tie-back cylinder 121, a liner hanger 122 and a lower inner casing 123, which are connected in sequence from top to bottom, are used to be lowered into the outer casing 110, and are suspended at the lower end of the outer casing 110 through the liner hanger 122, and are set, released and cemented; a differential pressure sliding sleeve 124 is provided at the toe end of the lower inner casing;

[0034] Upper inner casing 131, which is successively provided with a large-diameter hydraulic sliding sleeve 132, a deep-well large-diameter downhole safety valve 133, a large-diameter hydraulic formation isolation valve 134, a tie-back casing anchor 135 and an insert seal 136 from top to bottom; after being lowered into the outer casing 110, the insert seal 136 provided at the lower end of the upper inner casing 131 is used to cooperate with the tie-back cylinder 121 to achieve sealing and positioning, thereby realizing the docking of the upper inner casing 131 and the lower inner casing 123;

[0035] Multiple bridge plugs 140, which are respectively pumped into the lower inner casing 123 in batches via the upper inner casing 131 and are used for cluster perforation and fracturing operations respectively;

[0036] The electric pump string 150, which is successively provided with a composite cable 151, a production packer 152 and an electric pump unit 153 from top to bottom; the electric pump string 150 is lowered into the upper inner casing 131 through the composite cable 151, and the production packer 152 is located above the large-diameter hydraulic sliding sleeve 132; the electric pump string 150 is used for auxiliary flowback and production;

[0037] Among them, the large-diameter hydraulic sliding sleeve 132, the deep-well large-diameter downhole safety valve 133 and the large-diameter hydraulic formation isolation valve 134 are respectively connected with a first hydraulic control pipeline 161, a second hydraulic control pipeline 162 and a third hydraulic control pipeline 163 for real-time opening and closing; the inner diameters of the large-diameter hydraulic sliding sleeve 132, the deep-well large-diameter downhole safety valve 133, the large-diameter hydraulic formation isolation valve 134, the tie-back casing anchor 135, the insert seal 136, the tie-back cylinder 121 and the liner hanger 122 are all larger than that of the bridge plug 140.

[0038] In another embodiment, the outer diameters of the upper inner casing 131 and the lower inner casing 123 are 5.5 inches; the outer diameter of the outer casing is 9.625 inches.

[0039] In another embodiment, the inner diameter of the large-diameter hydraulic sliding sleeve 132 is the same as that of the tie-back casing anchor 135, and the maximum internal pressure that the large-diameter hydraulic sliding sleeve 132 can withstand is 10000 psi.

[0040] In another embodiment, the inner diameter of the deep-well large-diameter downhole safety valve 133 is the same as that of the upper inner casing 131, which can meet the requirement of a depth of 3000 m, and the maximum internal pressure it can withstand is 10000 psi.

[0041] In another embodiment, the inner diameter of the large-diameter hydraulic formation isolation valve 134 is the same as that of the tie-back casing anchor 135, which meets the requirement of a depth of 3000 m, and the maximum internal pressure it can withstand is 10000 psi.

[0042] A method for integrated operation of a fishing and electric pump anti-gas-lock fracturing production string, applying the fishing and electric pump anti-gas-lock fracturing production string 1 described in any one of the above, includes the following steps:

[0043] Step 1: Connect the tie-back cylinder 121, liner hanger 122, and lower inner sleeve 123 from top to bottom in sequence, lower them into the outer casing 110, and hang them in the outer casing 110 through the liner hanger 122, and then set and release the hanger and cement the well.

[0044] Step 2: A large-diameter hydraulic sliding sleeve 132, a deep-well large-diameter downhole safety valve 133, a large-diameter hydraulic formation isolation valve 134, a tie-back casing anchor 135, and an insert seal 136 are successively arranged on the upper inner casing 131 from top to bottom; lower the upper inner casing 131 into the outer casing 110; realize sealing and positioning through the cooperation of the insert seal 136 arranged at the lower end of the upper inner casing 131 and the tie-back cylinder 121, and further realize the butt joint of the upper inner casing 131 and the lower inner casing 123.

[0045] Step 3: Pressurize the upper inner casing 131 where the butt joint is successful to open the differential pressure sliding sleeve 124, so that the lower inner casing 123 is communicated with the formation; connect the perforating gun with the bridge plug 140; electrically connect the staged ignition device with the perforating gun and the bridge plug 140 respectively; then lower the perforating gun and the bridge plug 140 into the lower inner casing 123 through the upper inner casing 131 by means of pumping, and then realize the setting and releasing of the bridge plug 140 through the staged ignition device, lift the perforating gun to the upper perforating position, and then perform perforating operation through the staged ignition device. After the perforating operation is completed, lift out the perforating gun, and only leave the bridge plug 140 at the bottom of the well.

[0046] Step 4: Inject fracturing fluid into the upper inner casing 131, the fracturing fluid enters the lower inner casing 123 from the upper inner casing 131, and enters the formation through the perforation holes to realize the volume fracturing operation of the lowest layer.

[0047] Step 5: Connect another bridge plug 140 with the perforating gun, lower it into the lower inner casing by means of pumping, and realize the setting of the bridge plug 140, the perforating of the perforating section, and the volume fracturing according to the operation methods in Step 3 and Step 4; repeat this step for the third stage and above fracturing.

[0048] Step 6: After the last stage of fracturing is completed, close the large-diameter hydraulic formation isolation valve 134 through the third hydraulic control pipeline 163. Under the condition of not killing the well under pressure, the electric pump string 150 is successively provided with a composite cable 151, a production packer 152, and an electric pump unit 153 from top to bottom; lower the electric pump string 150 into the upper inner casing 131 through the composite cable 151, and make the production packer 152 set above the large-diameter hydraulic sliding sleeve 132 through the hydraulic control pipeline in the composite cable 151.

[0049] Step 7: Open the large-diameter hydraulic formation isolation valve 134 through the third hydraulic control pipeline 163, and confirm that the deep-well large-diameter downhole safety valve 133 is in the open state; start the electric pump unit 153 for auxiliary backflow and production, and the electric pump string 150 extracts the produced oil from the annulus between the composite pipe cable 151 and the upper inner casing 131; if the produced fluid contains a high amount of gas, the large-diameter hydraulic sliding sleeve 132 can be opened at any time through the first hydraulic control pipeline 161 for gas exhaust to prevent the electric pump unit 153 from being gas-locked.

[0050] In another embodiment, when well flushing is required, the large-diameter hydraulic sliding sleeve 132 and the large-diameter hydraulic formation isolation valve 134 are respectively in the open and closed states through the first hydraulic control pipeline 161 and the third hydraulic control pipeline 163 to perform a well flushing cycle, and the large-diameter hydraulic formation isolation valve 134 can prevent the well flushing fluid from entering the formation and polluting the reservoir.

[0051] In another embodiment, when a pump inspection is required, first close the large-diameter hydraulic formation isolation valve 134 and the deep-well large-diameter downhole safety valve 133 respectively through the third hydraulic control pipeline 163 and the second hydraulic control pipeline 162, then release the production packer 152 through the composite pipe cable 151, lift out the production packer 152 and the electric pump unit 153 through the composite pipe cable 151, and then complete the installation of the new production packer 152 and the electric pump unit 153 through the composite pipe cable 151.

[0052] In another embodiment, when the upper inner casing 123 needs to be lifted out later, first make the large-diameter hydraulic sliding sleeve 132 in the open state through the first hydraulic control pipeline 161, inject kill fluid into the annulus between the upper inner casing 131 and the outer casing 110, and the kill fluid enters the upper inner casing from the large-diameter hydraulic sliding sleeve 132 to perform well killing. After successful well killing, lift the upper inner casing and remove it from the wellhead.

[0053] In another embodiment, in Step 6, the pressure with pressure is not higher than the pressure-bearing capacity of the composite pipe cable 151.

[0054] In summary, the fishing and electric pump anti-gas-lock fracturing production integrated pipe string 1 and operation method of the present invention can achieve multi-stage stratified fracturing with one trip of the pipe string, quickly switch to artificial lift production without moving the pipe string after fracturing, and prevent the kill fluid from polluting the reservoir.

[0055] Although the embodiments of the present invention have been disclosed as above, it is not limited to only the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the field, additional modifications can be easily made. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the illustrated and described examples here.

Claims

1. A cast-in-place electric pump anti-gas lock fracturing production integrated pipe string, characterized in that: include: An outer casing, which is lowered into the well after the wellbore is drilled and sealed in the well; The tie-back tube, the liner hanger and the lower inner casing are connected in sequence from top to bottom, and are used to be lowered into the outer casing, and are hung on the lower end of the outer casing through the liner hanger, and are set, dropped and cemented; a differential pressure sleeve is provided at the toe end of the lower inner casing; The upper inner casing is provided with a large-diameter hydraulically controlled sliding sleeve, a deep well large-diameter downhole safety valve, a large-diameter hydraulically controlled formation isolation valve, a tie-back casing anchor and an insert seal in sequence from top to bottom; after the outer casing is lowered, the insert seal arranged at the lower end of the upper inner casing cooperates with the tie-back tube to achieve sealing and positioning, thereby achieving the docking of the upper inner casing and the lower inner casing; A plurality of bridge plugs are pumped into the lower inner casing in batches through the upper inner casing for performing cluster perforation and fracturing operations respectively; The electric pump string is provided with a composite pipe cable, a production packer and an electric pump unit in order from top to bottom; the electric pump string is lowered into the inner upper casing through the composite pipe cable, and the production packer is located above the large-diameter hydraulic control sliding sleeve; the electric pump string is used for auxiliary flowback and production; Among them, the large-diameter hydraulically controlled sliding sleeve, deep-well large-diameter downhole safety valve, and large-diameter hydraulically controlled formation isolation valve are respectively connected to the first hydraulically controlled pipeline, the second hydraulically controlled pipeline, and the third hydraulically controlled pipeline for real-time opening and closing; the inner diameters of the large-diameter hydraulically controlled sliding sleeve, deep-well large-diameter downhole safety valve, large-diameter hydraulically controlled formation isolation valve, tieback casing anchor, insert seal, tieback tube, and tail pipe hanger are all larger than the bridge plug.

2. The integrated tubular column for fracturing production with electric pump for casting and fishing and preventing gas lock according to claim 1 is characterized in that: The outer diameters of the upper inner sleeve and the lower inner sleeve are 5.5 inches; the outer diameter of the outer sleeve is 9.625 inches.

3. The integrated tubular column for fracturing production with electric pump for casting and fishing and preventing gas lock according to claim 1 is characterized in that: The inner diameter of the large-diameter hydraulic control sleeve is consistent with the inner diameter of the tieback casing anchor, and the maximum bearing internal pressure of the large-diameter hydraulic control sleeve is 10,000 psi.

4. The integrated tubular column for fracturing production with electric pump for casting and fishing and preventing gas lock according to claim 1 is characterized in that: The inner diameter of the deep well large-diameter downhole safety valve is consistent with the inner diameter of the upper inner casing, which can meet the requirements of a depth of 3000m and withstand a maximum internal pressure of 10000psi.

5. The integrated tubular column for fracturing production with electric pump for casting and fishing and preventing gas lock according to claim 1 is characterized in that: The inner diameter of the large-diameter hydraulically controlled formation isolation valve is consistent with the inner diameter of the tieback casing anchor, meeting the 3000m depth requirement and withstanding a maximum internal pressure of 10,000psi.

6. A method for operating an integrated pipe string for fracturing production with an electric pump to prevent gas lock, using the integrated pipe string for fracturing production with an electric pump to prevent gas lock as described in any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1: Connect the tie-back tube, liner hanger and lower inner casing in sequence from top to bottom, lower them into the outer casing, and hang them in the outer casing through the liner hanger, and then hang, release and cement them; Step 2: A large-diameter hydraulically controlled sliding sleeve, a deep-well large-diameter downhole safety valve, a large-diameter hydraulically controlled formation isolation valve, a tieback casing anchor and an insert seal are sequentially arranged on the upper inner casing from top to bottom; the upper inner casing is lowered into the outer casing; the insert seal arranged at the lower end of the upper inner casing cooperates with the tieback tube to achieve sealing and positioning, thereby achieving docking of the upper inner casing and the lower inner casing; Step 3: pressurize the upper inner casing that has been successfully docked, open the differential pressure sleeve, connect the lower inner casing with the formation, and connect the perforating gun to the bridge plug; electrically connect the graded ignition device to the perforating gun and the bridge plug respectively; then, the perforating gun and the bridge plug are lowered into the lower inner casing through the upper inner casing by pumping, and then the bridge plug is set and released by the graded ignition device, and the perforating gun is lifted up to the upper perforating position, and then the perforating operation is performed by the graded ignition device. After the perforating operation is completed, the perforating gun is lifted up, leaving only the bridge plug at the bottom of the well; Step 4: injecting fracturing fluid into the upper inner casing, the fracturing fluid enters the lower inner casing from the upper inner casing, and enters the formation through the perforated holes to achieve volume fracturing operation of the lowest layer; Step 5: connect another bridge plug to the perforating gun, lower it into the lower inner casing by pumping, and implement the setting of the bridge plug, perforation of the perforating section and volume fracturing according to the operation methods in Steps 3 and 4; repeat this step for the third and above fracturing; Step 6: After the last stage of fracturing is completed, the large-diameter hydraulic-controlled formation isolation valve is closed through the third hydraulic-controlled pipeline. In the case of wellbore pressure without well suppression, the electric pump string is provided with a composite pipe cable, a production packer and an electric pump unit from top to bottom in sequence; the electric pump string is lowered into the upper inner casing through the composite pipe cable, and the production packer is seated above the large-diameter hydraulic-controlled sliding sleeve through the hydraulic-controlled pipeline in the composite pipe cable; Step seven, open the large-diameter hydraulic-controlled formation isolation valve through the third hydraulic-controlled pipeline, and confirm that the large-diameter downhole safety valve of the deep well is in the open state; start the electric pump unit for auxiliary return and production, and the electric pump string will produce the produced oil from the annular space between the composite pipe cable and the upper inner casing; if the gas content in the produced fluid is high, the large-diameter hydraulic-controlled sliding sleeve can be opened at any time through the first hydraulic-controlled pipeline to exhaust gas to prevent gas lock of the electric pump unit.

7. The integrated pipe string operation method for throwing and fishing electric pumps to prevent gas lock fracturing production according to claim 6 is characterized in that: When backwashing is required, the large-diameter hydraulic-controlled sliding sleeve and the large-diameter hydraulic-controlled formation isolation valve are respectively opened and closed through the first hydraulic-controlled pipeline and the third hydraulic-controlled pipeline to perform a well-washing cycle. The large-diameter hydraulic-controlled formation isolation valve can prevent the well-washing fluid from entering the formation and contaminating the reservoir.

8. The integrated pipe string operation method for throwing and fishing electric pumps to prevent gas lock fracturing production according to claim 6 is characterized in that: When the pump needs to be inspected, first close the large-diameter hydraulically controlled formation isolation valve and the deep well large-diameter downhole safety valve through the third hydraulic control pipeline and the second hydraulic control pipeline respectively, then unseal the production packer through the composite pipe and cable, lift out the production packer and the electric pump unit through the composite pipe and cable, and then put a new production packer and electric pump unit into operation through the composite pipe and cable.

9. The integrated pipe string operation method for throwing and fishing electric pumps to prevent gas lock fracturing production according to claim 6 is characterized in that: When it is necessary to pull out the upper inner casing at a later stage, the large-diameter hydraulic control sliding sleeve is first opened through the first hydraulic control pipeline, and well killing fluid is injected into the annulus between the upper inner casing and the outer casing. The well killing fluid enters the upper inner casing from the large-diameter hydraulic control sliding sleeve to achieve well killing. After the well killing is successful, the upper inner casing is lifted up and the wellhead is pulled out.

10. The integrated pipe string operation method for throwing and fishing electric pumps to prevent gas lock fracturing production according to claim 6 is characterized in that: In step six, the pressure of the pressurized material is not higher than the pressure bearing capacity of the composite cable.

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