Integrated process pipe column and process flow for chemical flooding downward return oil well

Abstract

The invention relates to the technical field of oil field oil production engineering, in particular to an integrated process pipe column for a chemical flooding downward return oil well and a process flow. The device comprises an oil pipe, a casing pipe is arranged outside the oil pipe, the oil pipe is connected with an integrated tool string, the integrated tool string comprises a hanging packer, a blowout prevention switch, a plugging packer, a pressure buffer, a pressure trepanning detonation device, a perforating gun string, a double-ignition tail acoustic bullet and a dynamic negative pressure device, the hanging packer comprises a releasing tool, and the releasing tool is connected with the plugging packer. The suspension packer is connected with an oil pipe through a release, and a dynamic negative pressure device is arranged at the bottom of the oil pipe. According to the integrated process pipe column and the process flow for the chemical-flooding downward-returning oil well, the process pipe column can achieve the process of integrating hole patching, plugging and blowout prevention, blowout prevention and plugging are achieved, overflow-free rapid operation in the whole process of lifting and delivering the pipe column and descending a pump is achieved, one trip of lifting and descending the plugging pipe column is reduced, and the production efficiency is improved. And the cost of well killing or under-pressure operation is saved.

Description

Technical Field

[0001] The invention relates to the technical field of oil field production engineering, and in particular to an integrated process pipe column and process flow for chemical drive oil return wells. Background Art

[0002] The up-down return plugging process is the main technology for the development of chemical flooding return layers in Class II oil layers of oil fields. The main construction procedures for oil well return are hole patching, plugging, and pumping. However, the wellhead pressure is generally high after hole patching. There are two main ways to plug and pump the pipe: one is to circulate the well through solid-free well killing fluid after hole patching, and the conventional minor repair team completes the plugging and pumping, but the cost of high-density solid-free well killing fluid is high; the other is to use pressure operation construction to complete the plugging and pumping after hole patching, but the operation cost is high and the construction period is long. Therefore, in view of the above shortcomings, the present invention provides an integrated process pipe column and process flow for chemical flooding return oil wells. Summary of the invention

[0003] 1. Technical issues to be resolved: The present invention provides an integrated process pipe column and process flow for chemical drive oil return wells, so as to overcome the problem in the prior art that a conventional minor repair team cannot pump down a pump in time due to high wellhead pressure after the chemical drive oil return wells are refilled, and can realize environmentally friendly, efficient and low-cost construction of plugging and pumping down a pressure-free well after the chemical drive oil return wells are refilled.

[0004] (II) Technical solution: In order to solve the above technical problems, the present invention provides an integrated process string for chemical flooding oil return wells, comprising: The oil pipe has a casing on the outside, and the oil pipe is connected to an integrated tool string, which includes a hanging packer, a blowout preventer, a plugging packer, a pressure buffer, a pressure hole-opening detonator, a perforating gun string, a double-fire tail bomb and a dynamic negative pressure device. The bottom of the hanging packer is connected to the blowout preventer through a thread, the blowout preventer is connected to the plugging packer through a thread, the bottom end of the plugging packer is connected to the pressure buffer through a thread, the bottom end of the pressure buffer is the pressure hole-opening detonator, the bottom end of the pressure hole-opening detonator is connected to the perforating gun string through a thread, the perforating gun string is connected to the double-fire tail bomb through a thread, and the double-fire tail bomb is connected to the dynamic negative pressure device through a thread.

[0005] Preferably, the suspension packer comprises a release handle, and the suspension packer is connected to the oil pipe via the release handle.

[0006] Preferably, the bottom of the oil pipe is a dynamic negative pressure device.

[0007] Preferably, the dynamic negative pressure device is provided with a negative pressure device, and the dynamic negative pressure device absorbs the explosion pressure of the patching hole in real time through the negative pressure device.

[0008] Preferably, a detonator is provided inside the pressure hole opening detonator. When the pressure in the oil pipe reaches a certain value, the pressure hole opening detonator ignites the perforating gun string through the detonator.

[0009] A process flow based on an integrated process string for chemical flooding return wells, comprising: Step S1: determine the target well, connect the oil pipe to the well washing tool string, and wash the target well; Step S2: After the well washing process is completed, the oil pipe is connected to the well cleaning tool string, and the target well is cleaned; Step S3: After the well cleaning process is completed, the integrated tool string is assembled on the ground, the oil pipe is connected to the integrated tool string to form a process string, the length of the string is recorded, and the string is lowered; Step S4: Determine that the pipe string of step S3 is lowered into the designated position, open the blowout prevention switch in the forward direction, use the surface pump truck to pressurize the oil pipe, start the pressure hole opening detonator, ignite the perforating gun string through the pressure hole opening detonator, and start the perforating work; Step S5: After completing the perforation repair described in step S4, the pipe string is lifted to the plugging layer, and the plugging packer at the lower end of the plugging layer is set and the hanging packer at the upper end of the plugging layer is set and released by lifting and lowering; Step S6: After confirming that the hanging packer described in step S5 is released successfully, the oil pipe is pulled out, the bottom end of the oil pump is connected to the poke rod, and the poke rod is lowered into the designated position in the well through the oil pipe, and the blowout prevention switch is turned on; Step S7: confirm that the blowout prevention switch is turned on, lower the pump rod string, perform a pump-holding test and a pressure test on the string, and start the pump and put it into production after passing the test.

[0010] Preferably, the setting and releasing of the suspension packer are judged by observing the load change of the tubing string. After setting and releasing, the tubing string is lowered until the load is reduced by not less than 2 tons, the lowering is stopped, and then the tubing string is lifted up. If the lifting is smooth, it means that the setting and releasing of the suspension packer are successful.

[0011] Preferably, the pressure perforation detonation device is provided with a preset value, and when the pressure in the oil pipe reaches the preset value, the perforating gun string can ignite and perforate.

[0012] Preferably, the blowout preventer is activated by observing the change in casing pressure or opening the casing gate to observe whether there is well fluid outflow. If the casing pressure rises or the casing gate is opened to see if there is well fluid outflow, it means that the blowout preventer is successfully opened.

[0013] (III) Beneficial effects: The present invention provides an integrated process string and process flow for chemical drive oil return wells. The process string can realize an integrated process of perforation repair-plugging-blowout prevention. The perforation of the perforation repair layer is completed by starting a perforating gun string. After the perforation repair, the process string is lifted up and lowered to complete the setting and release of the plugging layer, and the plugging of the plugging layer is realized at the same time. The process string can prevent blowouts and plug, and the whole process of lifting and delivering the string and pumping can be realized without overflow and fast operation, which reduces one trip to lift and lower the plugging string and saves the cost of well killing or pressure operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The present invention is a schematic structural diagram of an integrated process string for a chemical flooding oil return well according to an embodiment of the present invention.

[0015] Among them, 1-oil pipe; 2-suspension packer; 3-blowout preventer switch; 4-plugging packer; 5-pressure buffer; 6-pressure opening detonator; 7-perforating gun string; 8-double-fire tail bomb; 9-dynamic negative pressure device. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by "left", "right", "up", "down", "inside" and "outside" are all based on the directions or positional relationships shown in the accompanying drawings. The purpose is only to facilitate the description of the present invention and simplify the description. It does not indicate or imply that the referred parts must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0018] Figure 1 FIG. 1 is a schematic diagram of the structure of an integrated process string for a chemical flooding oil return well according to an embodiment of the present invention. Figure 1 As shown, the invention provides an integrated process string for chemical flooding oil return wells, including an oil pipe 1, a suspension packer 2, a blowout preventer switch 3, a plugging packer 4, a pressure buffer 5, a pressure perforation detonator 6, a perforating gun string 7, a double-fire tail bomb 8 and a dynamic negative pressure device 9; The outside of the oil pipe 1 is a casing, and the oil pipe 1 is connected to an integrated tool string, which includes a hanging packer 2, a blowout preventer 3, a plugging packer 4, a pressure buffer 5, a pressure hole detonator 6, a perforating gun string 7, a double-fire tail bomb 8 and a dynamic negative pressure device 9. The bottom of the hanging packer 2 is connected to the blowout preventer 3 by a thread, the blowout preventer 3 is connected to the plugging packer 4 by a thread, the bottom end of the plugging packer 4 is connected to the pressure buffer 5 by a thread, the bottom end of the pressure buffer 5 is the pressure hole detonator 6, the bottom end of the pressure hole detonator 6 is connected to the perforating gun string 7 by a thread, the perforating gun string 7 is connected to the double-fire tail bomb 8 by a thread, and the double-fire tail bomb 8 is connected to the dynamic negative pressure device 9 by a thread.

[0019] In the integrated process string, the suspension packer 2, the blowout preventer 3, the plugging packer 4, the pressure buffer 5, the pressure opening detonator 6, the perforating gun string 7, the double-fire tail bomb 8 and the dynamic negative pressure device 9 together constitute an integrated tool string, the oil pipe 1 is connected to the integrated tool string, the suspension packer 2 includes a release handle, the suspension packer 2 is connected to the oil pipe 1 through the release handle, and the bottom of the oil pipe 1 is the dynamic negative pressure device 9.

[0020] In actual application, the dynamic negative pressure device 9 is provided with a negative pressure device, and the dynamic negative pressure device 9 absorbs the blasting pressure of the hole patching in real time through the negative pressure device. The pressure buffer 5 can reduce the impact of the blasting pressure of the hole patching. The pressure hole opening detonator 6 is provided with a detonator inside, and the pressure hole opening detonator 6 ignites the perforating gun string 7 through the detonator.

[0021] In the integrated process string, the perforating gun string 4 is arranged with the number of clusters and the number of holes according to the on-site requirements, the hole shape is circular, and the hole arrangement trajectory is a spiral trajectory.

[0022] The present invention also proposes a process flow based on an integrated process string for chemical flooding oil return wells, comprising: Step S1: determine the target well, connect the oil pipe to the well washing tool string, and wash the target well; Step S2: After the well washing process is completed, the oil pipe is connected to the well cleaning tool string, and the target well is cleaned; Step S3: After the well cleaning process is completed, the integrated tool string is assembled on the ground, the oil pipe is connected to the integrated tool string to form a process string, the length of the string is recorded, and the string is lowered; Step S4: Determine that the pipe string of step S3 is lowered into the designated position, open the blowout prevention switch in the forward direction, use the surface pump truck to pressurize the oil pipe, start the pressure hole opening detonator, ignite the perforating gun string through the pressure hole opening detonator, and start the perforating work; Step S5: After completing the perforation repair described in step S4, the pipe string is lifted to the plugging layer, and the plugging packer at the lower end of the plugging layer is set and the hanging packer at the upper end of the plugging layer is set and released by lifting and lowering; Step S6: After confirming that the hanging packer described in step S5 is released successfully, the oil pipe is pulled out, the bottom end of the oil pump is connected to the poke rod, and the poke rod is lowered into the designated position in the well through the oil pipe, and the blowout prevention switch is turned on; Step S7: confirm that the blowout prevention switch is turned on, lower the pump rod string, perform a pump-holding test and a pressure test on the string, and start the pump and put it into production after passing the test.

[0023] It should be noted that the hanging packer 2 can be both set and released. In this process flow, by observing the load changes of the process string, it is possible to determine whether the hanging packer 2 has completed setting and releasing. In actual application, when the process string is set and released, the string is lowered until the load is reduced by not less than 2 tons, and the lowering is stopped. Then the string is lifted up. If the lifting is smooth, it means that the hanging packer is successfully set and released.

[0024] In this process, a preset value is set inside the pressure hole opening detonator 6. When the pressure in the oil pipe reaches the preset value, the perforating gun string 7 can ignite and perforate. In actual application, the oil pipe 1 is pressurized by a ground pump truck. When the oil pipe pressure reaches a certain value, the impact piston in the pressure hole opening detonator hits the detonator, and the detonator enables the perforating gun string 7 to ignite and perforate, and then start the perforation work.

[0025] In the tubing string of this process, the blowout preventer 3 is in the closed state, isolating the high-pressure fluid at the bottom of the well at the lower end of the plugging string, without overflow at the wellhead, and the delivery string is pulled out. The bottom end of the oil pump is connected to the poke rod, and after being lowered into the designated position in the well through the oil pipe 1, the blowout preventer 3 is opened. By observing the change in casing pressure or opening the casing gate to observe whether there is well fluid flowing out, it can be judged whether the blowout preventer 3 is opened successfully. If the casing pressure rises or well fluid flows out when the casing gate is opened, it means that the blowout preventer switch is opened successfully.

[0026] After successful start-up, it will undergo pump-holding and pressure test tests. Only after passing the tests can it be put into production.

[0027] In this process, the tool string is delivered to the perforation repair layer by using the oil pipe, and the surface pump truck is used to start the pressure perforation detonation device through the oil pipe pressure control, ignite the perforating gun string, and complete the perforation repair. The dynamic negative pressure device and pressure buffer can quickly absorb the perforation repair explosion pressure and reduce the impact of the perforation repair explosion pressure on the tool string. After the perforation repair, the pipe string is lifted to the plugging layer, and the plugging packer at the lower end of the plugging layer and the hanging packer at the upper end of the plugging layer are set and released synchronously by lifting and lowering the oil pipe. After the pump is blocked and the pressure test is qualified, it is put into production. In actual application, the process pipe string is both blowout-proof and plugging, and the whole process of lifting and delivering the pipe string and pumping is realized without overflow and fast operation, which reduces one trip to lift and lower the plugging pipe string and saves the cost of well pressure or pressure operation.

[0028] In actual applications, the wellbore pressure of the chemical flooding oil return well is high after the perforation is repaired, which makes it difficult for the conventional operation team to pump in time. In order to overcome the relevant difficulties, an integrated process string and process flow for chemical flooding oil return wells are proposed. The working principle is described in detail below: In this embodiment, first, the oil pipe 1 is connected to the well-washing tool string, and the well is washed. After the well-washing process is completed, the oil pipe 1 is connected to the well-clearing tool string, and the well is cleared.

[0029] In actual application, after the well cleaning process is completed, an integrated tool string is assembled on the ground. The integrated tool string includes a hanging packer 2, a blowout preventer switch 3, a plugging packer 4, a pressure buffer 5, a pressure opening detonator 6, a perforating gun string 7, a double-fire tail bomb 8 and a dynamic negative pressure device 9. The oil pipe 1 is connected to the entire integrated tool string and combined into a process string. The staff needs to record the length of the string and lower the string.

[0030] In this embodiment, it is determined that the pipe string is lowered into the designated position, the blowout preventer 3 is opened in the positive direction, the oil pipe 1 is pressurized by a ground pump truck, and the pressure hole opening blasting device 6 is turned on. After the pressure gauge of the pressure hole opening blasting device 6 reaches the preset value, the perforating gun string 7 is ignited to achieve ignition perforation, and then the perforation repair work is started. The dynamic negative pressure device 9 can quickly absorb the perforation repair explosion pressure, and the pressure buffer 5 can reduce the impact of the perforation repair explosion pressure.

[0031] In actual application, after completing the hole patching, the pipe string is lifted up to the plugging layer, and the plugging packer 4 at the lower end of the plugging layer is set and sealed by lifting and lowering, and the hanging packer 2 at the upper end of the plugging layer is set and released. After confirming that the hanging packer 2 is released successfully, the oil pipe 1 is pulled out, and the bottom end of the oil pump is connected to the poke rod. After lowering it into the designated position in the well through the oil pipe 1, the blowout preventer 3 is opened, and the blowout preventer 3 is confirmed to be opened. The pump rod string is lowered, and the pipe string is subjected to pump-holding and pressure test. After passing the inspection, the pump is started and put into production.

[0032] In this embodiment, after setting and releasing, the tubing string is lowered until the load is reduced by 2 tons, the lowering is stopped, and then the tubing string is lifted up. The lifting is smooth, indicating that the setting and releasing of the suspension packer are successful.

[0033] The present invention provides an integrated process string and process flow for chemical drive oil return wells. The process string can realize an integrated process of perforation repair-plugging-blowout prevention. The perforation of the perforation repair layer is completed by starting a perforating gun string. After the perforation repair, the process string is lifted up and lowered to complete the setting and release of the plugging layer, and the plugging of the plugging layer is realized at the same time. The process string can prevent blowouts and plug, and the whole process of lifting and delivering the string and pumping can be realized without overflow and fast operation, which reduces one trip to lift and lower the plugging string and saves the cost of well killing or pressure operation.

[0034] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An integrated process string for chemical flooding oil return wells, characterized in that: include: An oil pipe (1), the outside of which is a casing, the oil pipe (1) is connected to an integrated tool string, the integrated tool string comprising a hanging packer (2), a blowout preventer (3), a plugging packer (4), a pressure buffer (5), a pressure hole-opening detonator (6), a perforating gun string (7), a double-fire tail bomb (8) and a dynamic negative pressure device (9), the bottom of the hanging packer (2) is connected to the blowout preventer (3) by a thread, the blowout preventer (3) is connected to the plugging packer (4) by a thread, the bottom end of the plugging packer (4) is connected to the pressure buffer (5) by a thread, the bottom end of the pressure buffer (5) is the pressure hole-opening detonator (6), the bottom end of the pressure hole-opening detonator (6) is connected to the perforating gun string (7) by a thread, the perforating gun string (7) is connected to the double-fire tail bomb (8) by a thread, and the double-fire tail bomb (8) is connected to the dynamic negative pressure device (9) by a thread.

2. The integrated process string for chemical flooding oil return well according to claim 1, characterized in that: The suspension packer (2) comprises a release handle, and the suspension packer (2) is connected to the oil pipe (1) via the release handle.

3. The integrated process string for chemical flooding oil return wells according to claim 1, characterized in that: The bottom of the oil pipe (1) is a dynamic negative pressure device (9).

4. The integrated process string for chemical flooding oil return well according to claim 3, characterized in that: The dynamic negative pressure device (9) is provided with a negative pressure device, and the dynamic negative pressure device (9) absorbs the explosion pressure of the patching hole in real time through the negative pressure device.

5. The integrated process string for chemical flooding oil return well according to claim 1, characterized in that: The pressure hole opening detonating device (6) is provided with a detonator inside, and the pressure hole opening detonating device (6) ignites the perforating gun string (7) through the detonator.

6. A process flow of an integrated process string for chemical flooding oil return wells proposed in any one of claims 1 to 5, comprising: Step S1: determine the target well, connect the oil pipe to the well washing tool string, and wash the target well; Step S2: After the well washing process is completed, the oil pipe is connected to the well cleaning tool string, and the target well is cleaned; Step S3: After the well cleaning process is completed, the integrated tool string is assembled on the ground, the oil pipe is connected to the integrated tool string to form a process string, the length of the string is recorded, and the string is lowered; Step S4: Determine that the pipe string of step S3 is lowered into the designated position, open the blowout prevention switch in the forward direction, use the surface pump truck to pressurize the oil pipe, start the pressure hole opening detonator, ignite the perforating gun string through the pressure hole opening detonator, and start the perforating work; Step S5: After completing the perforation repair described in step S4, the pipe string is lifted to the plugging layer, and the plugging packer at the lower end of the plugging layer is set and the hanging packer at the upper end of the plugging layer is set and released by lifting and lowering; Step S6: After confirming that the hanging packer described in step S5 is released successfully, the oil pipe is pulled out, the bottom end of the oil pump is connected to the poke rod, and the poke rod is lowered into the designated position in the well through the oil pipe, and the blowout prevention switch is turned on; Step S7: confirm that the blowout prevention switch is turned on, lower the pump rod string, perform a pump-holding test and a pressure test on the string, and start the pump and put it into production after passing the inspection.

7. The process according to claim 6, characterized in that: The setting and releasing of the suspension packer (2) are judged by observing the load change of the pipe string. After setting and releasing, the pipe string is lowered until the load is reduced by not less than 2 tons, and then the lowering is stopped. Then the pipe string is lifted up. If the lifting is smooth, it means that the setting and releasing of the suspension packer are successful.

8. The process according to claim 6, characterized in that: The pressure perforation detonation device (6) is provided with a preset value, and when the pressure in the oil pipe reaches the preset value, the perforating gun string (7) can ignite and perforate.

9. The process according to claim 6, characterized in that: The blowout preventer (3) is activated by observing the change in casing pressure or opening the casing gate to observe whether well fluid flows out. If the casing pressure rises or well fluid flows out when the casing gate is opened, it means that the blowout preventer (3) is successfully opened.

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