Hydraulic injection-production integrated oil production process tubing and setting method

Abstract

A hydraulic injection-production integrated oil production process tubing and setting method relates to the field of oil production technology. It includes an oil-water separator, an injection pump, a production pump, bridge packers, and a sealing mechanism. Each bridge packer has a bridge-shaped channel, and these channels are connected by a double-layer process pipe. The setting mechanism within each bridge packer is a hydraulic setting mechanism. There are two bridge packers. During setting, the injection pump is activated. Under the action of the injection pump, the pressure in the sealed space above the injection pump continuously increases, which in turn pushes the hydraulic setting mechanism within each packer, causing the packer to set. This invention creatively proposes a novel hydraulic setting approach, utilizing the pressure generated by the injection pump to achieve hydraulic setting of the packers. This not only eliminates the problems of tubing and sucker rod wear caused by mechanical setting, as well as the low reliability of setting, but also eliminates the need for surface pressure testing equipment, reducing operating costs.

Description

Technical Field

[0001] This invention relates to the field of efficient oilfield exploitation, and in particular to hydraulic injection-production integrated oil production process tubing and setting method. Background Technology

[0002] In offshore and onshore oil drilling and extraction, it is often necessary to inject water into the formation to increase oil production. In traditional technology, water, as an oil displacement agent, is injected into the formation through a separate injection well, and then extracted along with crude oil through production wells. The drawbacks of this injection and extraction method are that the volume of produced fluid is large, the proportion of ineffective production is high, and the extracted fluid needs to be separated again on the surface, which is a very large amount of work.

[0003] To address the aforementioned issues, engineers designed a co-well injection and production process. For example, patent document CN101025080B discloses a co-well injection and production method. The tubing structure employed includes an oil-water separator, an injection pump, a production pump, a packer with a bridge-type channel, and a sealing mechanism to isolate the injection and production pumps. During operation, liquid seeps out from the produced layer and moves upwards. After being separated by the oil-water separator, the separated water enters the inner cavity of the bridge-type packer and then, under the action of the injection pump, passes laterally through the packer into the injection layer. The separated oil flows upwards through the bridge-type channel within the packer and is then pumped to the surface by the production pump.

[0004] The disadvantages of the aforementioned prior art are as follows: Due to the presence of the sealing mechanism, even if the plunger of the production pump is not lowered, the hydraulic pressure from the ground cannot be transmitted along the tubing to the area below the sealing mechanism. In other words, the prior art cannot use the hydraulic setting principle to set the packer; only a mechanical setting method can be used. However, during mechanical setting, the tubing string is prone to bending under mechanical pressure, leading to uneven wear of the sucker rod and tubing. Furthermore, when multiple packers are used in series, the setting reliability of the mechanical setting method is far inferior to that of the hydraulic setting method.

[0005] Therefore, this invention aims to design a hydraulically set bridge packer that can be applied to the same-well injection and production process scenario, thereby realizing a hydraulically set same-well injection and production process tubing. Summary of the Invention

[0006] This invention provides a hydraulic injection-production integrated oil production process tubing string and setting method. The purpose is to provide a unique method to achieve hydraulic setting based on the tubing string structure in existing same-well injection-production technology, thereby avoiding the problems of tubing and sucker rod wear and low setting reliability that exist when mechanical setting is applied to same-well injection-production technology.

[0007] The technical problem solved by this invention is achieved by the following technical solution: This invention provides a hydraulic injection-production integrated oil production process string, including an oil-water separator, an injection pump, a production pump, a bridge packer I, a bridge packer II, a bridge packer III, and a sealing mechanism. Each of the bridge packers I, II, and III is provided with a bridge channel. An injection channel is also provided on the bridge packer corresponding to the downhole injection layer. The bridge channels in each bridge packer are connected by a double-layer process pipe.

[0008] The bridge packer used in the hydraulic injection-production integrated oil production process tubing adopts hydraulic setting, and the pressure of hydraulic setting comes from the injection pump.

[0009] The injection channel is equipped with a blocking structure, which can block the injection channel during hydraulic setting to prevent hydraulic leakage. After setting is completed, the blocking structure can release the blockage of the injection channel, thereby allowing the injection channel to open.

[0010] As a preferred embodiment, the sealing structure has the following two types:

[0011] The first type of sealing structure includes a baffle plate, which is fixedly installed in the injection channel and blocks the injection channel. After the packer is set, the injection pump continues to work, causing the pressure in the sealed space above it to continue to rise, which in turn crushes the baffle plate and opens the injection channel. The bridge packer using this sealing structure is called a constant pressure injection packer.

[0012] The second type of sealing structure includes a water nozzle and a soluble baffle. Both the water nozzle and the soluble baffle are installed in the injection channel. The soluble baffle is located at one end of the water nozzle. Before the soluble baffle dissolves, the water nozzle blocks the injection channel. The soluble baffle can prevent the water nozzle from sliding. After the soluble baffle dissolves, the water nozzle can slide along the axial direction of the bridge packer 2, thereby connecting the inside and outside of the bridge packer 2, that is, opening the injection channel. The bridge packer 2 using this sealing structure is called a quantitative injection packer.

[0013] As a preferred embodiment, each of the bridge packers is the constant pressure injection packer.

[0014] As a preferred embodiment, each of the bridge packers is the quantitative dispensing packer.

[0015] As a preferred embodiment, there is one and only one constant pressure injection packer, and the constant pressure injection packer corresponds to the injection layer with the worst permeability.

[0016] As a preferred embodiment, after the soluble block dissolves and the water nozzle slides along the axial direction of the metering packer, one end of the water nozzle is connected to the inner cavity of the metering packer through the first connecting hole, and the other end of the water nozzle is connected to the outside of the metering packer through the second connecting hole, thereby forming the injection channel connecting the inside and outside of the metering packer.

[0017] As a preferred embodiment, the sealing mechanism includes a sealing seat, which is fixedly installed on the inner side of the oil pipe. The sucker rod corresponding to the sealing seat is slidably installed in the through hole in the center of the sealing seat and achieves a sealing fit through a sealing element. A necked section is provided on the sucker rod corresponding to the sealing seat, and a guide pin is provided on the outer side of the necked section. Correspondingly, a closed-loop slide is machined on the inner side of the sealing seat.

[0018] When the sucker rod is raised to its highest position during normal operation, the sucker rod is raised further, and the guide pin can slide into the closed-loop slide. After one up-and-down reciprocating motion, it is hooked on the sealing seat. After another up-and-down reciprocating motion, the guide pin can disengage from the sealing seat downwards.

[0019] Both the extraction pump and the injection pump are enclosed by a pump barrel and a plunger. The plunger is inserted into the pump barrel from above. By reciprocating within the pump barrel, the liquid below the extraction pump or the injection pump can be pumped to the top.

[0020] When the guide pin is attached to the sealing seat, the necked section allows a gap to be formed between the sucker rod and the sealing seat. At the same time, the plunger of the production pump disengages upward from the corresponding pump barrel, thereby forming a gap between the pump barrel and the plunger of the production pump. Meanwhile, the plunger of the injection pump remains inside the corresponding pump barrel to ensure a seal between the plunger and the pump barrel.

[0021] This invention also provides a method for setting up a hydraulic injection-production integrated oil production process tubing, comprising the following steps:

[0022] Step 1: Start the surface pumping unit. The pumping unit drives the production pump and injection pump through the sucker rod.

[0023] Step two: After the liquid seeping out of the well is separated by the oil-water separator, the separated water enters the closed space between the injection pump and the sealing mechanism. Then, under the action of pump pressure, it pushes the hydraulic setting mechanism in the bridge packer, so that each bridge packer is set.

[0024] The beneficial effects of this invention are:

[0025] 1. This invention creatively proposes a novel hydraulic setting concept, which utilizes the pressure generated by the injection pump to achieve hydraulic setting of the packer. This not only eliminates the problems of uneven wear on the oil pipe and sucker rod caused by mechanical setting, as well as the low reliability of setting, but also eliminates the need for ground pressure testing equipment, thus reducing operating costs.

[0026] In order to achieve hydraulic setting of packers under the structural limitations of existing injection and production process tubing, this invention adds baffles or soluble baffles to the existing bridge packers. During setting, the setting pressure will not leak from the injection channel of the bridge packer. After setting, the injection channel can be opened by crushing the baffles or dissolving the soluble baffles to achieve injection into the injection layer.

[0027] 2. In this invention, by setting a constant pressure injection packer with a baffle-type sealing mechanism, the injection channel can be immediately opened by high pressure after the packer is set, thereby enabling rapid production after the packer is set, shortening the construction cycle and reducing the impact of construction on production.

[0028] Meanwhile, the present invention places the constant pressure injection packer in the injection layer with the lowest permeability, so that the injection layer receives preferential injection, which helps to ensure the balance of injection between each injection layer.

[0029] 3. In this invention, the quantitative injection packer is equipped with a sealing structure including a water nozzle and a soluble baffle. Within 1-3 days after construction is completed, the soluble baffle inside the quantitative injection packer dissolves, opening the injection channel and enabling injection. Simultaneously, by replacing water nozzles with different diameters, the injection volume at each injection layer can be independently adjusted, achieving stratified water injection based on injection and production within the same well.

[0030] 4. This invention improves the sealing mechanism in the prior art by setting a closed-loop slide in the sealing seat and a guide pin in the necked part of the sucker rod, so that the sucker rod string can be suspended on the sealing seat. At the same time as suspension, a gap appears at both the production pump and the sealing mechanism. After the gap appears, the ground pressure equipment is connected to the upper end of the tubing string, and hydraulic setting can be achieved through the ground pressure source, thereby improving the adaptability to different working conditions. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0032] Figure 2 This is a schematic diagram of the quantitative dispensing packer.

[0033] Figure 3 yes Figure 2 A magnified view of a portion of point A in the middle.

[0034] Figure 4 This is a schematic diagram of a constant pressure injection packer.

[0035] Figure 5 yes Figure 4 A magnified view of a section at point B.

[0036] Figure 6 This is a schematic diagram of the structure of the extraction pump, sealing mechanism, and injection pump during normal production.

[0037] Figure 7 This is a schematic diagram of the structure of the extraction pump, sealing mechanism, and injection pump during ground pressurization.

[0038] Figure 8 It is a plan view of closed-loop slides in 6 or 7.

[0039] In the diagram: 1. First connecting hole; 2. Water nozzle; 3. Second connecting hole; 4. Soluble baffle; 5. Baffle plate; 6. Tubing; 7. Production pump; 8. Quantitative injection packer; 9. Sealing mechanism; 10. Constant pressure injection packer; 12. Non-injection bridge packer; 13. Produced layer; 14. Injection pump; 15. Oil-water separator; 16. Double-layer process pipe; 17. Sucker rod; 18. Bridge channel; 19. Pump barrel; 20. Plunger; 21. Sealing seat; 22. Seal; 23. Closed-loop slide; 24. Neck section; 25. Guide pin. Detailed Implementation

[0040] The present invention will be further described below with reference to the accompanying drawings.

[0041] like Figure 1 As shown, this embodiment includes an oil-water separator 15, an injection pump 14, a production pump 7, a bridge packer, and a sealing mechanism 9. Both the injection pump 14 and the production pump 7 are conventional plunger-type oil pumps, each consisting of a pump barrel 19 and a plunger 20. There are at least two bridge packers to seal the upper and lower sides of a single injection layer. Each bridge packer contains a bridge channel 18, and the bridge packer corresponding to the downhole injection layer also has an injection channel. The bridge channels 18 within each bridge packer are connected via a double-layer process pipe 16, forming a packer group. The upper end of the packer group is connected to the pump barrel 19 of the production pump 7, and the lower end is connected to the pump barrel 19 of the injection pump 14. The oil-water separator 15 is connected below the pump barrel 19 of the injection pump 14. The bridge packers contain bridge channels 18, and the bridge channels 18 within each bridge packer are connected via the interlayer of the double-layer process pipe 16. The plunger 20 in the injection pump 14 and the plunger 20 in the production pump 7 are connected in series via the sucker rod 17. The sealing mechanism 9 is located between the production pump 7 and the packer assembly to seal the outer space of the sucker rod 17, thereby blocking the upper end of the packer assembly. After the blockage, the liquid pumped upward by the injection pump 14 can only enter laterally into the injection channels on the metering packer 8 and the constant pressure injection packer 10, and then enter the injection layer.

[0042] In this embodiment, three bridge packers are provided. The lowest bridge packer is called the non-injection bridge packer 12, which is used to isolate the produced layer 13 and the injection layer and does not have an injection function. The other two bridge packers are equipped with injection channels, which serve to isolate the formation and inject.

[0043] The above structure already exists in the prior art cited in the background section, and will not be described again here.

[0044] The main innovation of this invention lies in the fact that the bridge packer used in the hydraulic injection-production integrated oil production process tubing employs hydraulic setting. This invention creatively proposes a novel hydraulic setting approach, utilizing the pressure generated by the injection pump 14 to achieve hydraulic setting of the packer. This not only eliminates the problems of uneven wear on the tubing 6 and sucker rod 17 caused by mechanical setting, as well as the low reliability of setting, but also eliminates the need for surface pressurization equipment, reducing operating costs.

[0045] like Figure 2 As shown in Figure 4, a sealing structure is provided on the injection channel. The sealing structure can block the injection channel during hydraulic setting, thereby preventing hydraulic leakage. During setting, the injection pump 14 is started. Under the action of the injection pump 14, the pressure in the sealed space above the injection pump 14 continuously accumulates and increases, which in turn pushes the hydraulic setting mechanism in each packer, so that the packer is set. After setting, each packer can isolate the injection layer in the formation so that the water separated by the oil-water separator 15 can be directed into the injection layer. After setting is completed, the sealing structure can release the blockage of the injection channel, thereby opening the injection channel.

[0046] In this embodiment, the blocking mechanism has the following two optional structures:

[0047] The first type, such as Figure 4 , 5 As shown, the sealing structure includes a baffle 5, which is fixedly installed in the injection channel and blocks the injection channel. After the packer is set, the injection pump 14 continues to work, causing the pressure in the sealed space above it to continue to rise, which in turn crushes the baffle 5 and opens the injection channel. The bridge packer using this sealing structure is called a constant pressure injection packer 10.

[0048] After setting, the injection pump 14 continues to operate, and a pressure higher than the setting pressure ruptures the baffle 5, releasing the blockage of the injection channel and allowing the injection channel to quickly become open. Therefore, the first type of sealing structure is characterized by its ability to quickly put into production after the packer is set, shortening the construction cycle and reducing the impact of construction on production.

[0049] The second type, such as Figure 2 , 3As shown, the sealing structure includes a water nozzle 2 and a soluble baffle 4. Both the water nozzle 2 and the soluble baffle 4 are disposed in the injection channel. The soluble baffle 4 is located at one end of the water nozzle 2. Before the soluble baffle 4 dissolves, the water nozzle 2 blocks the injection channel, and the soluble baffle 4 can prevent the water nozzle 2 from sliding. The bridge-type packer using this sealing structure is called a metered dispensing packer 8.

[0050] After the soluble block 4 dissolves and the water nozzle 2 slides axially along the quantitative injection packer 8, one end of the water nozzle 2 communicates with the inner cavity of the quantitative injection packer 8 through the first connecting hole 1, and the other end of the water nozzle 2 communicates with the outside of the quantitative injection packer 8 through the second connecting hole 3, thus forming the injection channel connecting the inside and outside of the quantitative injection packer 8. After the work is completed, within 1-3 days after the completion of the construction, the soluble block 4 can be dissolved by the downhole liquid. After dissolution, the injection channel is opened, and injection is realized. At the same time, by replacing the water nozzle 2 with different diameters, the injection volume of each injection layer can be adjusted independently, and stratified water injection can be achieved on the basis of injection and production in the same well.

[0051] It should be noted that the two sealing structures mentioned above only modify the structure of the injection channel of the existing bridge packer, and do not improve the other structures of the bridge packer. Therefore, the other structures of the bridge packer will not be described in detail.

[0052] In practice, all bridge packers can be set as either constant pressure injection packers 10 or quantitative injection packers 8. However, the best implementation is that there is only one constant pressure injection packer 10, and the constant pressure injection packer 10 corresponds to the injection layer with the worst permeability, so that the injection layer is given priority injection, which helps to ensure the balance of injection between each injection layer.

[0053] like Figure 6 , 7 As shown in Figure 8, in this embodiment, the sealing mechanism 9 includes a sealing seat 21, which is fixedly installed on the inner side of the oil pipe 6. The sucker rod 17 corresponding to the sealing seat 21 is slidably installed in the through hole in the center of the sealing seat 21 and achieves sealing cooperation through the sealing element 22. A necking section 24 is provided on the sucker rod 17 corresponding to the sealing seat 21. A guide pin 25 is provided on the outer side of the necking section 24. Correspondingly, a closed-loop slide 23 is machined on the inner side of the sealing seat 21.

[0054] When the sucker rod 17 is raised to its highest normal operating position, further raising of the sucker rod 17 allows the guide pin 25 to slide into the closed-loop slide 23. After one up-and-down reciprocating motion, it hooks onto the sealing seat 21. After another up-and-down reciprocating motion, the guide pin 25 can disengage from the sealing seat 21. It should be noted that in the prior art, there are various structures that can achieve the disengagement and engagement of two parts through reciprocating motion, as described in reference books or textbooks. The structure composed of the closed-loop slide 23 and the guide pin 25 used in this embodiment is only one type of prior art.

[0055] Both the production pump 7 and the injection pump 14 enclose a pump barrel 19 and a plunger 20. The plunger 20 is inserted into the pump barrel 19 from above. By reciprocating within the pump barrel 19, the plunger 20 can pump the liquid below the production pump 7 or the injection pump 14 to the top. The structure of the production pump 7 or the injection pump 14 described here is the most widely used oil pump structure in the prior art, and will not be elaborated further.

[0056] When the guide pin 25 is attached to the sealing seat 21, the necked section 24 allows a gap to be formed between the sucker rod 17 and the sealing seat 21. At the same time, the plunger 20 of the production pump 7 disengages upward from the corresponding pump barrel 19, thereby forming a gap between the pump barrel 19 and the plunger 20 of the production pump 7. Meanwhile, the plunger 20 of the injection pump 14 remains inside the corresponding pump barrel 19 to ensure a seal between the plunger 20 and the pump barrel 19.

[0057] This invention improves the design of the sealing mechanism 9 in the prior art. By setting a closed-loop slide 23 in the sealing seat 21 and a guide pin 25 in the necked part of the sucker rod 17, the sucker rod 17 can be suspended on the sealing seat 21. At the same time as suspension, gaps appear at both the production pump 7 and the sealing mechanism 9. After the gaps appear, the ground pressure equipment is connected to the upper end of the tubing string 6, and hydraulic setting can be achieved through the ground pressure source, thereby improving the adaptability to different working conditions.

[0058] This invention also provides a method for setting up a hydraulic injection-production integrated oil production process tubing, comprising the following steps:

[0059] Step 1: Start the surface pumping unit. The pumping unit drives the production pump 7 and the injection pump 14 through the sucker rod 17.

[0060] Step 2: After the liquid seeping out from the well is separated by the oil-water separator 15, the separated water enters the closed space between the injection pump 14 and the sealing mechanism 9. Then, under the action of the pump pressure of the injection pump 14, it pushes the hydraulic setting mechanism in the bridge packer, so that each bridge packer is set.

Claims

1. A hydraulic injection-production integrated oil production process string, comprising an oil-water separator (15), an injection pump (14), a production pump (7), a bridge packer I, a bridge packer II, a bridge packer III, and a sealing mechanism (9), wherein each of the bridge packer I, bridge packer II, and bridge packer III is provided with a bridge channel (18), and an injection channel is simultaneously provided on the bridge packer corresponding to the downhole injection layer, and the bridge channels (18) in each bridge packer are connected by a double-layer process pipe (16), characterized in that: The bridge packer used in the hydraulic injection-production integrated oil production process tubing is set by hydraulic setting, and the pressure of hydraulic setting comes from the injection pump (14). The injection channel is provided with a blocking structure, which can block the injection channel during hydraulic setting to prevent hydraulic leakage. After setting is completed, the blocking structure can release the blockage of the injection channel, thereby allowing the injection channel to conduct. The sealing structure has the following two types: The first type of sealing structure includes a baffle (5), which is fixedly installed in the injection channel. The baffle (5) can break under pressure, thereby opening the injection channel. The bridge packer using this sealing structure is called a constant pressure injection packer (10). The second type of sealing structure includes a water nozzle (2) and a soluble baffle (4). Both the water nozzle (2) and the soluble baffle (4) are set in the injection channel. The soluble baffle (4) is located at one end of the water nozzle (2). Before the soluble baffle (4) dissolves, the water nozzle (2) blocks the injection channel. The soluble baffle (4) can prevent the water nozzle (2) from sliding. After the soluble baffle (4) dissolves, the water nozzle (2) can slide along the axial direction of the bridge packer II, thereby connecting the inside and outside of the bridge packer II, that is, the injection channel is opened. The bridge packer II using this sealing structure is called a quantitative injection packer (8). The sealing mechanism (9) includes a sealing seat (21), which is fixedly installed on the inner side of the oil pipe (6). The sucker rod (17) corresponding to the sealing seat (21) is slidably installed in the through hole in the center of the sealing seat (21) and achieves sealing cooperation through the sealing element (22). A necking section (24) is provided on the sucker rod (17) corresponding to the sealing seat (21). A guide pin (25) is provided on the outer side of the necking section (24). Correspondingly, a closed-loop slide (23) is machined on the inner side of the sealing seat (21). By applying an external force to the sucker rod (17) on the ground to make it reciprocate, the guide pin (25) can be hung in the closed-loop slide (23) or disengaged from the closed-loop slide (23). Both the extraction pump (7) and the injection pump (14) enclose the pump barrel (19) and the plunger (20). The plunger (20) is inserted into the pump barrel (19) from above. By reciprocating within the pump barrel (19) through the plunger (20), the liquid below the extraction pump (7) or the injection pump (14) can be pumped to the top. When the guide pin (25) is attached to the sealing seat (21), the necking section (24) can create a gap between the sucker rod (17) and the sealing seat (21). At the same time, the plunger (20) of the extraction pump (7) moves upward and disengages from the corresponding pump barrel (19), thereby creating a gap between the pump barrel (19) and the plunger (20) of the extraction pump (7). Meanwhile, the plunger (20) of the injection pump (14) remains inside the corresponding pump barrel (19) to ensure a seal between the plunger (20) and the pump barrel (19).

2. The hydraulic injection-production integrated oil production process tubing according to claim 1, characterized in that: There is one and only one constant pressure injection packer (10), and the constant pressure injection packer (10) corresponds to the position of the injection layer with the worst permeability.

3. The hydraulic injection-production integrated oil production process tubing according to claim 1, characterized in that: After the soluble block (4) dissolves and the water nozzle (2) slides along the axial direction of the metering packer (8), one end of the water nozzle (2) is connected to the inner cavity of the metering packer (8) through the first connecting hole (1), and the other end of the water nozzle (2) is connected to the outside of the metering packer (8) through the second connecting hole (3), thereby forming the injection channel connecting the inside and outside of the metering packer (8).

4. A method for setting and sealing a hydraulic injection-production integrated oil production process tubing as described in any one of claims 1-3, characterized in that, The process includes the following: Step 1: Start the oil pumping unit on the ground. The oil pumping unit drives the production pump (7) and the injection pump (14) through the sucker rod (17). Step 2: After the liquid seeping out of the well is separated by the oil-water separator (15), the separated water enters the closed space between the injection pump (14) and the sealing mechanism (9), and then, under the action of the pump pressure, pushes the hydraulic setting mechanism in the bridge packer to set each bridge packer.

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