A horizontal well oil production balance control string, system and method

Abstract

This invention belongs to the field of oilfield development technology, specifically relating to a horizontal well oil production equalization control string, system, and method. The equalization control string of this invention is organically composed of a guide plug, tailpipe, equalization inflow control tool module, packer, chamfered tubing, and drop packer. The equalization control string, drop packer, production string, and tubing constitute a horizontal well equalization oil production system. This invention overcomes the interference caused by differences in wellbore flow resistance between sections within a formation cluster due to factors such as long horizontal well sections, reservoir heterogeneity, and wellbore trajectory, by segmenting and sealing the perforated sections of the horizontal well. This suppresses injected water breakthrough and bottom water coning, and evenly utilizes the production capacity of each section. The overall assembly and construction of this invention are simple, the operation is straightforward, it enables downhole adaptive control, and once deployed into the well, it remains effective for a long period without human intervention.

Description

Technical Field

[0001] This invention belongs to the field of oilfield development technology, specifically relating to a horizontal well oil production balance control string, system, and method. Background Technology

[0002] Horizontal wells, as an important means to increase single-well production and transform development methods, have been used in various oilfields for many years. Currently, over 80% of PetroChina's proven reserves are low-permeability reservoirs, and horizontal wells are the main technology for effectively utilizing low-quality reservoirs. Horizontal well deployment accounts for 50%–65% of the annual production capacity of oilfields. Horizontal well sections are long, with numerous stimulation sections, resulting in significant interference and production differences between sections and clusters within the same formation. Therefore, there is an urgent need to achieve efficient and balanced oil production in each horizontal section, suppress water injection breakthrough and bottom water coning, evenly utilize the production capacity of each formation, and improve the development effect of horizontal wells.

[0003] Currently, balanced oil production technology may employ packers to seal segmented sections, each equipped with a one-way injection valve and an automatic gas and water control valve. Gas is injected from the surface into each reservoir, driving crude oil along formation pores or fractures to the perforation channels and into the wellbore. Oil, gas, and water then enter the integrated injection-production tubing through the downhole automatic gas and water control valves, and the downhole crude oil is extracted to the surface via natural flow or mechanical extraction. Alternatively, packers can separate oil and water sections, adjusting the flow rates of the distribution nozzles and drain nozzles during pumping to regulate the pressure of oil and water within the reservoir, maintaining a balance between oil and water and improving oil recovery. Another approach involves running a central tubing in a horizontal well section to overcome wellbore pressure drop and friction, limiting the inflow at the heel and releasing production capacity at the toe, thus achieving balanced oil production.

[0004] However, the above-mentioned oil production technologies all suffer from problems such as complex process tubing, the need for manual monitoring and adjustment on the surface, and low levels of automation. Summary of the Invention

[0005] This invention provides a horizontal well oil production balance control string, system, and method. One objective is to provide a device and method that can solve the problems of long horizontal well sections, numerous stimulation sections, prominent interference contradictions between sections and clusters within the layer, and significant differences in production. Another objective is to provide a device and method with a short overall construction cycle, simple operation, and the ability to effectively avoid delays in energy production.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A horizontal well oil production equalization control string includes a guide plug, a tailpipe, an equalization inflow control tool module, a packer, a chamfered tubing, and a drop-out packer; multiple packers are provided, and the multiple packers separate the formation sections; an equalization inflow control tool module is connected between adjacent packers via connecting tubing; the foremost equalization inflow control tool module is connected to one end of the tailpipe, and the other end of the tailpipe is connected to a guide plug; the last equalization inflow control tool module is connected to the drop-out packer via chamfered tubing.

[0007] The packer used is a Y445 cannula packer.

[0008] The packer is a slipless, liquid-expanding packer.

[0009] The balanced inflow control tool module includes an upper connector, a pressure-sensing valve, a sensing chamber, a shape memory alloy spring, an adjusting component, a transmission component, a slide valve, a side bridge inlet, a central flow channel, a housing, and a lower connector. The housing is a tubular structure with a central flow channel. The upper and lower ends of the housing are respectively connected to the upper and lower connectors, and the side walls of the upper and lower connectors are provided with threads for connecting to chamfered oil pipes, connecting oil pipes, or tailpipes. A pressure-sensing valve is connected to the outer side wall of the housing near the upper connector end. A sensing chamber is provided on the housing, and the pressure-sensing valve is connected to the inlet of the sensing chamber. A shape memory alloy spring is connected inside the sensing chamber, one end of which is fixed to the inner side wall of the sensing chamber, and the other end of which is connected to the slide valve through the adjusting component. The slide valve is slidably connected between the housing and the side bridge inlet.

[0010] A horizontal well balanced oil production system includes at least a balanced control string, and also includes a dropper string, a production string, and tubing; the dropper string is used for running the balanced control string into the well and for pressurizing and setting it, and is placed inside the tubing during the running and pressurizing and setting of the balanced control string; the production string is used for oil production; during oil production, the production string is placed inside the tubing and is sealed and connected to the dropper packer at the upper end of the balanced control string.

[0011] The production tubing includes a tube, a pump, a sucker rod, and a pumping unit; the upper end of the equalization control tubing is connected to the tubing via the tube; the tubing contains a pump, and the upper end of the pump is connected to the pumping unit via the sucker rod.

[0012] A method for balanced oil production in a horizontal well balanced oil production system includes the following steps. Step 1: Treat the wellbore; The wellbore is cleaned and flushed with sand until it reaches the bottom of the artificial well. Step 2: Assemble the horizontal well production equalization tubing string; Step 3: Lower the assembled horizontal well equalization production string into the target formation within the horizontal well. Step 4: After confirming that the setting depth of the release packer in the equalization control string is correct, insert steel balls. After the balls are delivered to the correct position, pressurize and set the release packer. Step 5: Pressurize to the preset pressure and stabilize for the preset time. Then, pressurize to the preset value and suddenly reduce the pressure to the preset value to release the pressure and remove the release tube. Step 6: Assemble the production tubing and run it into the wellbore to seal it with the release packer at the top of the balance control tubing to form the oil production system; Step 7: Start the pumping unit. If the pressure in a certain section is abnormal, the pressure sensing valve on the balance inflow control module in this section will open, and the well fluid will enter the sensing chamber. When the shape memory alloy spring encounters the high temperature of the well fluid, the slide valve will close, restricting the fluid from entering this layer. Conversely, after the pressure returns to normal, the pressure sensing valve will close, the temperature will drop, the shape memory alloy spring will return to its original state, the slide valve will open, and the produced fluid in this section will re-enter the central flow channel, achieving real-time balanced oil production in the horizontal well section.

[0013] Step five involves pressurizing to a preset pressure of 10 MPa, stabilizing the pressure for 5 minutes, then pressurizing to 12 MPa and then suddenly dropping to 2 MPa to release the grip.

[0014] Beneficial effects: (1) This invention overcomes the interference of wellbore flow resistance differences caused by factors such as long horizontal well sections, reservoir heterogeneity, and wellbore trajectory between clusters within the layer by dividing the perforated sections of the horizontal well section into segments and sealing them. Each segment corresponds to a balanced inflow control tool module, thereby suppressing the breakthrough of injected water and bottom water coning, and uniformly maximizing the production capacity of each layer.

[0015] (2) The present invention is easy to assemble and construct, simple to operate, and can be adaptively controlled downhole. Once it is lowered into the well, it can be effective for a long time without human intervention.

[0016] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1This is a schematic diagram of the structure of the device of the present invention; Figure 2 This is a schematic diagram of the balanced inflow control tool module in this invention.

[0019] In the diagram: 1. Guide plug; 2. Tailpipe; 3. Balanced inflow control module; 4. Packer; 5. Chamfered tubing; 6. Release packer; 7. Insert pipe; 8. Pump; 9. Tubing; 10. Sucker rod; 11. Pumping unit; 12. Upper connector; 13. Pressure sensing valve; 14. Sensing chamber; 15. Memory alloy spring; 16. Adjusting component; 17. Transmission component; 18. Slide valve; 19. Side bridge inlet; 20. Central flow channel; 21. Housing; 22. Lower connector. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] Example 1: according to Figure 1 and Figure 2 The diagram shows a horizontal well oil production equalization control string, including a guide plug 1, a tailpipe 2, an equalization inflow control tool module 3, a packer 4, a chamfered tubing 5, and a drop-out packer 6. Multiple packers 4 are provided, and these packers 4 separate the formation sections. An equalization inflow control tool module 3 is connected between adjacent packers 4 via connecting tubing. The foremost equalization inflow control tool module 3 is connected to one end of the tailpipe 2, and the other end of the tailpipe 2 is connected to the guide plug 1. The last equalization inflow control tool module 3 is connected to the drop-out packer 6 via the chamfered tubing 5.

[0022] In actual use, the design of the guide plug 1 ensures the overall sealing of the pipeline.

[0023] In practical applications, multiple packers 4 and one drop packer 6 separate the layers. The number of packers 4 is determined according to the requirements of horizontal segment separation. The drop packer 6 is located above the inclination point and serves to lock and anchor the entire equilibrium control string.

[0024] A balanced inflow control module 3 is provided between each pair of packers 4. During operation, when the pressure exceeds the upper limit of the balanced inflow control module 3, the module is closed, restricting the fluid in this section from entering the tubing and allowing other layers to produce capacity.

[0025] This invention overcomes the interference caused by differences in wellbore flow resistance between segments within a layer cluster due to factors such as long horizontal well sections, reservoir heterogeneity, and wellbore trajectory. It suppresses injected water breakthrough and bottom water coning, and evenly utilizes the production capacity of each layer.

[0026] The horizontal well balanced oil production device of this invention is easy to assemble and construct, simple to operate, and features downhole adaptive control. Once deployed, it remains effective for a long time without human intervention.

[0027] Example 2: according to Figure 1 The horizontal well oil production balance control string shown differs from that in Embodiment 1 in that the drop-out packer 6 is a Y445 type insertion packer.

[0028] Furthermore, the packer 4 is a slipless, liquid-expanding packer.

[0029] In actual use, the drop packer 6 adopts the Y445 type insert packer. If the pump fails and needs to be replaced, the insert 7 is lifted from the ground together during pump inspection. The parts below the packer remain in the wellbore. After replacing the entire pump, the insert 7 is reinserted into the packer to reassemble the production tubing.

[0030] Packer 4 is a slipless, liquid-expanding packer, which facilitates effective sealing and subsequent removal.

[0031] Example 3: according to Figure 1 and Figure 2 The horizontal well oil production equalization control string shown differs from Embodiment 1 in that: the equalization inflow control tool module 3 includes an upper connector 12, a pressure sensing valve 13, a sensing cavity 14, a shape memory alloy spring 15, an adjusting component 16, a transmission component 17, a slide valve 18, a lateral bridge inlet 19, a central flow channel 20, a housing 21, and a lower connector 22; the housing 21 is a tubular structure with a central flow channel 20; the upper and lower ends of the housing 21 are respectively connected to the upper connector 12 and the lower connector 22, and the side walls of the upper connector 12 and the lower connector 22 are provided with... It is provided with threads for connection to the chamfered oil pipe 5, connecting oil pipe or tail pipe 2; a pressure sensing valve 13 is connected to the outer wall of the housing 21 near the upper connector 12; a sensing chamber 14 is provided on the housing 21, and the pressure sensing valve 13 is connected to the inlet of the sensing chamber 14; a shape memory alloy spring 15 is connected inside the sensing chamber 14, one end of the shape memory alloy spring 15 is fixed to the inner side wall of the sensing chamber 14, and the other end of the shape memory alloy spring 15 is connected to the slide valve 18 through the adjusting member 16; the slide valve 18 is slidably connected between the housing 21 and the side bridge inlet 19.

[0032] In actual use, when the pressure in a certain section is abnormal, the pressure sensing valve 13 opens, and the well fluid enters the sensing chamber 14. When the shape memory alloy spring 15 encounters the high temperature of the well fluid, the slide valve 18 closes, restricting the fluid from entering this layer. Conversely, when the pressure returns to normal, the pressure sensing valve 13 closes, the temperature drops, the shape memory alloy spring 15 returns to its original state, the slide valve 18 opens, and the produced fluid in this section enters the central flow channel 20 again through the lateral bridge inlet 19, achieving real-time balanced oil production in the horizontal well section.

[0033] Example 4: Reference Figure 1 and Figure 2 A horizontal well balanced oil production system includes at least a balanced control string, and also includes a dropper string, a production string, and tubing 9; the dropper string is used for running the balanced control string into the well and for pressurizing and setting it, and is placed inside the tubing 9 during the running of the balanced control string and pressurizing and setting it; the production string is used for oil production; during oil production, the production string is placed inside the tubing 9 and is sealed and connected to the dropper packer 6 at the upper end of the balanced control string.

[0034] Furthermore, the production string includes a tubing 7, an oil pump 8, a sucker rod 10, and an oil pumping unit 11; the upper end of the equalization control string is connected to the oil pipe 9 through the tubing 7; the oil pipe 9 is equipped with an oil pump 8, and the upper end of the oil pump 8 is connected to the oil pumping unit 11 through the sucker rod 10.

[0035] In practical use, the wellbore is first cleaned and sand-washed until the bottom of the artificial well is reached. Then, the horizontal well production equalization string is assembled. Next, the assembled horizontal well production equalization string is run into the target formation within the horizontal well. After confirming the setting depth of the release packer 6 in the equalization control string is correct, a steel ball is inserted. Once the ball is in place, the release packer 6 is pressure-set. The pressure is increased to a preset 10 MPa and then stabilized for 5 minutes. Afterward, the pressure is increased to 12 MPa and then suddenly dropped to 2 MPa to release the packer. The release string is then removed. Finally, the production string is assembled and run into the well. The inner tube is sealed to the upper end of the equalization control string and the release packer 6 to form an oil production system. Then, the pumping unit 11 is started. If the pressure in a certain section is abnormal, the pressure sensing valve 13 on the equalization inflow control tool module 3 in this section opens, and the well fluid enters the sensing chamber 14. When the shape memory alloy spring 15 encounters the high temperature well fluid, the slide valve 18 closes, restricting the fluid in this layer from entering. Conversely, after the pressure returns to normal, the pressure sensing valve 13 closes, the temperature drops, the shape memory alloy spring 15 returns to its original state, the slide valve 18 opens, and the produced fluid in this section re-enters the central flow channel 20, achieving real-time equalization oil production in the horizontal well section.

[0036] This invention overcomes the interference caused by differences in wellbore flow resistance between sections within a layer cluster due to factors such as long horizontal well sections, reservoir heterogeneity, and wellbore trajectory. It also suppresses injected water breakthrough and bottom water coning, and evenly utilizes the production capacity of each layer.

[0037] The invention is easy to assemble and construct, simple to operate, and can be adaptively controlled downhole. Once deployed, it can remain effective for a long time without human intervention.

[0038] Example 5: Reference Figure 1 and Figure 2 A method for balanced oil production in a horizontal well balanced oil production system includes the following steps. Step 1: Treat the wellbore; The wellbore is cleaned and flushed with sand until it reaches the bottom of the artificial well. Step 2: Assemble the horizontal well production equalization tubing string; Step 3: Lower the assembled horizontal well equalization production string into the target formation within the horizontal well. Step 4: After confirming that the setting depth of the release packer 6 in the equalization control string is correct, insert the steel ball. After the ball is delivered to the correct position, pressurize and set the release packer 6. Step 5: Pressurize to the preset pressure and stabilize for the preset time. Then, pressurize to the preset value and suddenly reduce the pressure to the preset value to release the pressure and remove the release tube. Step 6: Assemble the production tubing and lower it into the wellbore to seal it with the release packer 6 at the upper end of the equalization control tubing to form the oil production system; Step 7: Start the pumping unit 11. If the pressure in a certain section is abnormal, the pressure sensing valve 13 on the balance inflow control tool module 3 in this section will open, and the well fluid will enter the sensing chamber 14. When the shape memory alloy spring 15 encounters the high temperature of the well fluid, the slide valve 18 will close, restricting the fluid from entering this layer. Conversely, after the pressure returns to normal, the pressure sensing valve 13 will close, the temperature will drop, the shape memory alloy spring 15 will return to its original state, the slide valve 18 will open, and the produced fluid in this section will re-enter the central flow channel 20, achieving real-time balanced oil production in the horizontal well section.

[0039] Furthermore, step five involves pressurizing to a preset pressure of 10 MPa, stabilizing the pressure for 5 minutes, then pressurizing to 12 MPa and then suddenly dropping to 2 MPa to release the grip.

[0040] In practical use, this invention overcomes the interference of wellbore flow resistance differences caused by factors such as long horizontal well sections, reservoir heterogeneity, and wellbore trajectory between inter-layer clusters by segmenting and sealing the perforated sections of the horizontal well section. It also suppresses injected water breakthrough and bottom water coning, and evenly utilizes the production capacity of each layer.

[0041] The invention is easy to assemble and construct, simple to operate, and can be adaptively controlled downhole. Once deployed, it can remain effective for a long time without human intervention.

[0042] Where there is no conflict, those skilled in the art can combine the relevant technical features in the above examples according to the actual situation to achieve the corresponding technical effects. Specific details of the various combinations will not be elaborated here.

[0043] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0044] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0045] The above description is merely a preferred embodiment of the present invention. The present invention is not limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. Any simple modifications, equivalent variations, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the present invention.

Claims

1. A horizontal well oil production balance control string, characterized in that: It includes a guide plug (1), a tailpipe (2), a balance inflow control tool module (3), a packer (4), a chamfered tubing (5), and a release packer (6); multiple packers (4) are provided, and multiple packers (4) separate the layers; a balance inflow control tool module (3) is connected between adjacent packers (4) through connecting tubing; the balance inflow control tool module (3) at the foremost end is connected to one end of the tailpipe (2), and the other end of the tailpipe (2) is connected to the guide plug (1); the balance inflow control tool module (3) at the end is connected to the release packer (6) through the chamfered tubing (5); The balanced inflow control tool module (3) includes an upper connector (12), a pressure sensing valve (13), a sensing cavity (14), a shape memory alloy spring (15), an adjusting component (16), a transmission component (17), a slide valve (18), a side bridge inlet (19), a central flow channel (20), a housing (21), and a lower connector (22). The housing (21) is a tubular structure with a central flow channel (20) in the center. The upper and lower ends of the housing (21) are respectively connected to the upper connector (12) and the lower connector (22). The side walls of the upper connector (12) and the lower connector (22) are provided with a connection for connecting with the chamfered oil pipe (5). The oil pipe or tailpipe (2) is connected by a thread; a pressure sensing valve (13) is connected to the outer wall of the housing (21) near the upper connector (12); a sensing cavity (14) is provided on the housing (21), and the pressure sensing valve (13) is connected to the inlet of the sensing cavity (14); a memory alloy spring (15) is connected inside the sensing cavity (14), one end of the memory alloy spring (15) is fixed to the inner wall of the sensing cavity (14), and the other end of the memory alloy spring (15) is connected to the slide valve (18) through the adjusting member (16); the slide valve (18) is slidably connected between the housing (21) and the side bridge inlet (19).

2. The horizontal well oil production balance control string as described in claim 1, characterized in that: The drop-out packer (6) is a Y445 cannula packer.

3. The horizontal well oil production balance control string as described in claim 1, characterized in that: The packer (4) is a self-expanding packer without slips when it comes into contact with liquid.

4. A horizontal well balanced oil production system, characterized in that: It includes at least the balance control string as described in any one of claims 1-3, and further includes a dropout string, a production string, and tubing (9); the dropout string is used for running the balance control string into the well and for pressurizing and setting it, and is placed inside the tubing (9) during the running of the balance control string into the well and for pressurizing and setting it; the production string is used for oil production; during oil production, the production string is placed inside the tubing (9) and is sealed and connected to the dropout packer (6) at the upper end of the balance control string.

5. A horizontal well balanced oil production system as described in claim 4, characterized in that: The production string includes a tube (7), an oil pump (8), a sucker rod (10), and an oil pumping unit (11); the upper end of the equalization control string is connected to the oil pipe (9) through the tube (7); the oil pipe (9) is equipped with an oil pump (8), and the upper end of the oil pump (8) is connected to the oil pumping unit (11) through the sucker rod (10).

6. A method for balanced oil production in a horizontal well balanced oil production system as described in any one of claims 4 or 5, characterized in that: Includes the following steps, Step 1: Treat the wellbore; The wellbore is cleaned and flushed with sand until it reaches the bottom of the artificial well. Step 2: Assemble the horizontal well production equalization tubing string; Step 3: Lower the assembled horizontal well equalization production string into the target formation within the horizontal well. Step 4: After confirming that the setting depth of the release packer (6) in the equalization control string is correct, insert the steel ball and pressurize the release packer (6) after the ball is delivered to the position. Step 5: Pressurize to the preset pressure and stabilize for the preset time. Then, pressurize to the preset value and suddenly reduce the pressure to the preset value to release the pressure and remove the release tube. Step 6: Assemble the production tubing and lower it into the wellbore to seal it with the release packer (6) at the upper end of the equalization control tubing to form the oil production system; Step 7: Start the pumping unit (11). If the pressure in a certain section is abnormal, the pressure sensing valve (13) on the balance inflow control tool module (3) in this section will open, and the well fluid will enter the sensing chamber (14). When the memory alloy spring (15) encounters the high temperature well fluid, the slide valve (18) will close, restricting the fluid in this layer from entering. Conversely, after the pressure returns to normal, the pressure sensing valve (13) will close, the temperature will drop, the memory alloy spring (15) will return to its original state, the slide valve (18) will open, and the produced fluid in this section will re-enter the central flow channel (20) for real-time balanced oil production in the horizontal well section.

7. The balanced oil production method for a horizontal well balanced oil production system as described in claim 6, characterized in that: Step five involves pressurizing to a preset pressure of 10 MPa, stabilizing the pressure for 5 minutes, then pressurizing to 12 MPa and then suddenly dropping to 2 MPa to release the grip.

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