Tubular column device capable of meeting simultaneous reinjection of water produced by single well

Abstract

The utility model belongs to the technical field of natural gas extraction, and relates to a tubular column device capable of meeting simultaneous reinjection of water produced by a single well. Comprising a production casing, an outer pipe and an inner pipe, and the production casing can play a role in providing borehole protection and supporting a well body wall. The water inlet hole is located below the lower packer, and formation water of the first target layer enters the inner pipe through the water inlet hole to be discharged. The upper packer is arranged above a second target layer, the lower packer is arranged below the second target layer, and reinjection formation water enters the space among the production casing pipe, the outer pipe, the upper packer and the lower packer through the inner pipe and the drainage hole and is finally drained into the second target layer through the water outlet hole. Wherein the inserting pipe is matched with the lower packer in a sealing mode and used for separating a discharging channel and a reinjection channel of formation water. According to the utility model, the separated formation water can be reinjected into the shallow layer of the original well, so that the reinjection work amount of the formation water is greatly reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of natural gas exploitation, and relates to a pipe string device capable of simultaneously reinjecting produced water from a single well. Background Art

[0002] For gas reservoirs that have already seen water, a common water management strategy is to significantly increase the drainage rate of individual wells to protect the reservoir and improve its recovery rate. However, where to go with this large amount of produced formation water remains a thorny issue.

[0003] At present, the method for treating formation water is often to lead the produced water to the reinjection well for reinjection. For gas reservoirs whose producing layers are the Cretaceous Brazil Formation and the Bashkirk Formation, since the Cretaceous Brazil Formation and the Bashkirk Formation are both above 7000m in depth, if the produced formation water is reinjected into the above two layers, a very high pumping pressure is required. The existing surface equipment is basically unable to meet the requirements of reinjecting formation water into the Cretaceous Brazil Formation and the Bashkirk Formation. Therefore, the produced formation water is generally reinjected into the shallow Neogene Kuqa Formation at a depth of 3000m.

[0004] For reinjection wells, single wells that have failed exploration are preferably perforated in the shallow layer, and injection pipes are run to reinject formation water. Alternatively, new wells can be drilled to the shallow layer and used as reinjection wells. However, both of these methods require the operation or drilling of a single well, as well as the construction of a surface water pipeline. Drilling new wells to the shallow layer is also a significant engineering effort.

[0005] In summary, in the prior art, single wells that have failed in exploration and newly drilled wells are used as reinjection wells for reinjecting formation water, which has the problem of large engineering workload. Utility Model Content

[0006] The purpose of the utility model is to provide a tubing device that can meet the simultaneous reinjection of water produced by a single well, so as to solve the technical problem of large engineering workload in the prior art of using single wells that have failed in exploration and newly drilled wells as reinjection wells for formation water. The utility model can reinject the separated formation water into the shallow layer of the original well, greatly reducing the engineering workload of reinjection of formation water.

[0007] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0008] The utility model discloses a pipe string device capable of simultaneously reinjecting produced water from a single well, comprising a production casing, an outer pipe passing through the production casing, and an inner pipe passing through the outer pipe;

[0009] An upper packer and a lower packer are provided between the production casing and the outer pipe, a cannula seal is provided between the outer pipe and the inner pipe, a plurality of drainage holes are provided on the outer pipe, the drainage holes are located between the upper packer and the lower packer, the cannula seal is located below the plurality of drainage holes, a water outlet hole and a water inlet hole are provided on the production casing, the water outlet hole is located between the upper packer and the lower packer, and the water inlet hole is located below the lower packer.

[0010] Furthermore, the production casing, outer pipe and inner pipe are coaxially arranged.

[0011] Furthermore, a perforated short section is sleeved on the outer tube, and a plurality of drainage holes are opened on the perforated short section.

[0012] Furthermore, there is a gap between the production casing and the outer pipe, and there is a gap between the outer pipe and the inner pipe.

[0013] Furthermore, the cannula seal is located between the perforated sub and the lower packer.

[0014] Furthermore, the top outlet of the inner tube is flush with the top inlet of the outer tube.

[0015] Furthermore, the top outlet of the inner tube is higher than the top inlet of the outer tube.

[0016] Furthermore, the top outlet of the inner tube is connected to a water storage device.

[0017] Furthermore, the top inlet of the outer tube is connected to the outlet of the water injection pump, and the inlet of the water injection pump is connected to the water storage device.

[0018] Furthermore, a pressure sensor is provided between the production casing and the outer pipe, and the pressure sensor is connected to a data collection component.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The utility model includes a production casing, an outer pipe and an inner pipe. The production casing can provide wellbore protection and provide support for the wellbore wall. The water inlet hole is located below the lower packer, and the formation water of the first target layer enters the inner pipe through the water inlet hole and is discharged. The upper packer is placed above the second target layer, and the lower packer is placed below the second target layer. The reinjected formation water enters the space between the production casing, the outer pipe, the upper packer and the lower packer through the inner pipe and the drainage hole, and is finally discharged into the second target layer through the water outlet hole. The intubation seal cooperates with the lower packer to separate the discharge channel and the reinjection channel of the formation water. The utility model can reinject the separated formation water into the shallow layer of the original well, greatly reducing the engineering workload of the reinjection of the formation water.

[0021] 2. The casing, outer tube and inner tube of the utility model are coaxially arranged, which is convenient for installation and maintenance and improves the overall stability and reliability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0023] Among them: 1. Production casing; 2. Outer pipe; 3. Inner pipe; 4. Upper packer; 5. Perforated short joint; 6. Intubation seal; 7. Lower packer; 8. First target layer; 9. Second target layer. DETAILED DESCRIPTION

[0024] In order to help those skilled in the art better understand the present invention, 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 embodiments described 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 making creative efforts should fall within the scope of protection of the present invention.

[0025] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0026] The present invention is described in further detail below with reference to the accompanying drawings:

[0027] See also Figure 1 The utility model discloses a pipe string device capable of simultaneously reinjecting produced water from a single well, comprising a production casing 1. The production casing 1 can provide wellbore protection and provide support for the wellbore wall.

[0028] An outer pipe 2 is passed through the production casing 1 , and an inner pipe 3 is passed through the outer pipe 2 . The inner pipe 3 is used to extract formation water from the first target layer 8 , and the gap between the outer pipe 2 and the inner pipe 3 is used to reinject formation water into the second target layer 9 .

[0029] An upper packer 4 and a lower packer 7 are provided between the production casing 1 and the outer pipe 2. A cannula seal 6 is provided between the outer pipe 2 and the inner pipe 3. The outer pipe 2 is provided with a plurality of drainage holes, the drainage holes being located between the upper packer 4 and the lower packer 7, and the cannula seal 6 being located below the drainage holes. The production casing 1 is provided with a water outlet and a water inlet, the water outlet being located between the upper packer 4 and the lower packer 7. The upper packer 4 is positioned above the second target layer 9, and the lower packer 7 is positioned below the second target layer 9. Reinjected formation water enters the space between the production casing 1, the outer pipe 2, the upper packer 4, and the lower packer 7 through the drainage holes, and is finally discharged into the second target layer 9 through the water outlet. The water inlet is located below the lower packer 7. Formation water in the first target layer 8 enters the inner pipe 3 through the water inlet and is discharged. The cannula seal 6, in conjunction with the lower packer 7, is used to separate the discharge channel and the reinjection channel for formation water.

[0030] To sum up, the water inlet hole on the production casing 1 and the inner tube 3 constitute the discharge channel of the formation water; the outer tube 2 and the inner tube 3 form the first reinjection space in the annular space above the insert seal 6, and the space between the production casing 1, the outer tube 2, the upper packer 4 and the lower packer 7 forms the second reinjection space. The first reinjection space, the drainage hole, the second reinjection space and the water outlet hole constitute the reinjection channel of the formation water; the insert seal 6 cooperates with the lower packer 7 to separate the discharge channel and the reinjection channel of the formation water.

[0031] In specific use, the formation water of the first target layer 8 is discharged to the surface through the discharge channel, collected and separated, and then injected into the second target layer 9 through the reinjection channel. The utility model can reinject the separated formation water into the shallow layer of the original well, greatly reducing the engineering workload of the formation water reinjection.

[0032] Example 1:

[0033] See also Figure 1 This embodiment discloses a pipe string device capable of simultaneously reinjecting produced water from a single well, comprising a production casing 1, an outer pipe 2 passing through the production casing 1, and an inner pipe 3 passing through the outer pipe 2;

[0034] An upper packer 4 and a lower packer 7 are provided between the production casing 1 and the outer pipe 2, a cannula seal 6 is provided between the outer pipe 2 and the inner pipe 3, a plurality of drainage holes are provided on the outer pipe 2, the drainage holes are located between the upper packer 4 and the lower packer 7, the cannula seal 6 is located below the plurality of drainage holes, a water outlet hole and a water inlet hole are provided on the production casing 1, the water outlet hole is located between the upper packer 4 and the lower packer 7, and the water inlet hole is located below the lower packer 7.

[0035] Preferably, the production casing 1, outer pipe 2 and inner pipe 3 are coaxially arranged, which facilitates installation and maintenance and improves the overall stability and reliability of the system.

[0036] Preferably, a perforated nipple 5 is sleeved on the outer tube 2 , and a plurality of drainage holes are opened on the perforated nipple 5 .

[0037] Preferably, there is a gap between the production casing 1 and the outer pipe 2 , and there is a gap between the outer pipe 2 and the inner pipe 3 .

[0038] Preferably, the cannula seal 6 is located between the perforated sub 5 and the lower packer 7 .

[0039] Preferably, the top outlet of the inner tube 3 is flush with the top inlet of the outer tube 2 .

[0040] Preferably, the top outlet of the inner tube 3 is higher than the top inlet of the outer tube 2 .

[0041] Preferably, the top outlet of the inner tube 3 is connected to a water storage device.

[0042] Preferably, the top inlet of the outer tube 2 is connected to the outlet of the water injection pump, and the inlet of the water injection pump is connected to the water storage device.

[0043] Preferably, a pressure sensor is provided between the production casing 1 and the outer pipe 2, and the pressure sensor is connected to a data collection component.

[0044] Based on the above structure, the specific method of using the utility model is as follows:

[0045] A water outlet hole and a water inlet hole are opened on the production casing 1. The water outlet hole corresponds to the second target layer 9, and the water inlet hole corresponds to the first target layer 8. The outer pipe 2 and the inner pipe 3 are installed.

[0046] An upper packer 4 is placed above the second target layer 9, and a lower packer 7 is placed below the second target layer 9. A perforated sub 5 is installed on the outer pipe 2. The perforated sub 5 has a plurality of drainage holes. The perforated sub 5 is located between the upper packer 4 and the lower packer 7. A cannula seal 6 is installed between the outer pipe 2 and the inner pipe 3. The cannula seal 6 is located between the perforated sub 5 and the lower packer 7.

[0047] The formation water of the first target layer 8 enters the production casing 1 through the water inlet hole on the production casing 1. Due to the sealing effect of the cannula seal 6 and the lower packer 7, the formation water is discharged to the water storage device on the surface through the inner pipe 3. After passing through the separator on the ground, the natural gas and the formation water are separated;

[0048] The separated formation water is discharged into the space between the outer pipe 2 and the inner pipe 3 and the drainage holes on the perforated nipple 5 into the space between the production casing 1, the outer pipe 2, the upper packer 4 and the lower packer 7, and finally injected into the second target layer 9 through the water outlet hole on the production casing 1.

[0049] Example 2:

[0050] This embodiment discloses a tubing string device capable of simultaneously reinjecting produced water from a single well, comprising: an outer tube 2, an inner tube 3 and a perforated sub 5. The outer tube 2 is sleeved on the outside of the inner tube 3, and the two are concentric. The outer tube 2 is not connected to the inner tube 3. The inner tube 3 is used to extract formation water from a first target layer 8, and the outer tube 2 is used to reinject the formation water into a second target layer 9. The perforated sub 5 is arranged on the outer tube 2 and is located at a corresponding position of the second target layer 9. The perforated sub 5 is used to discharge the formation water reinjected by the outer tube 2.

[0051] Specifically, the inner tube 3 is arranged in the outer tube 2, and there is a certain distance between the outer wall of the inner tube 3 and the inner wall of the outer tube 2. The length relationship between the outer tube 2 and the inner tube 3 is not limited. The inner tube 3 can be longer than the outer tube 2, or the outer tube 2 can be longer than the inner tube 3, or the two are equal. The perforated short section 5 is arranged on the outer tube 2 and is located at the position of the outer tube 2 corresponding to the second target layer 9. During the setting process, the nozzle of the inner tube 3 close to the ground needs to be higher than the nozzle of the outer tube 2, or the nozzles of the inner tube 3 and the outer tube 2 are level, in order to prevent the inner tube 3 and the outer tube 2 from affecting each other. The position relationship of the nozzles of the inner tube 3 and the outer tube 2 away from the ground is not limited. The nozzle of the inner tube 3 can be inside the outer tube 2, or the nozzle of the inner tube 3 can be outside the outer tube 2, or the nozzles of the two are level, and there is no specific limitation. The inner tube 3 and the outer tube 2 can be disconnected by providing a cannula seal 6 between them, or by placing the opening of the inner tube 3 outside the outer tube 2. It should be noted that the disconnection between the outer tube 2 and the inner tube 3 here refers to the fact that during the process of extracting stratum water by the inner tube 3, the formation water transported in the inner tube 3 cannot enter the outer tube 2. At the same time, the formation water reinjected in the outer tube 2 cannot enter the inner tube 3 during the reinjection process.

[0052] During operation, the inner pipe 3 draws formation water from the first target layer 8 to the surface and injects it into the outer pipe 2 via a surface injection pump. When the reinjected formation water reaches the location where the perforated sub 5 is located in the outer pipe 2, it is released into the second target layer 9 through the holes in the perforated sub 5. The first target layer 8 is the Cretaceous Brazil Formation and the Bashijiqik Formation, and the second target layer 9 is the Neogene Kuche Formation.

[0053] In some embodiments, the tubing structure capable of simultaneously reinjecting produced water from a single well also includes: a cannula seal 6, which is sleeved on the inner tube 3 and located between the inner tube 3 and the outer tube 2. The cannula seal 6 is located below the perforated short section 5. The cannula seal 6 seals the outer tube 2, so that the inner tube 3 and the outer tube 2 are not connected, and the reinjected formation water is above the cannula seal 6.

[0054] Specifically, the cannula seal 6 is sleeved onto the inner tube 3 and seals the gap between the outer wall of the inner tube 3 and the inner wall of the outer tube 2, thereby preventing the inner tube 3 from communicating with the outer tube 2. It can also be understood that the inner tube 3 and the outer tube 2 are connected via the cannula seal 6. During operation, the water injection pump on the surface injects extracted formation water into the outer tube 2. The formation water moves downward in the outer tube and is released at the perforated sub 5. However, due to the limited number of openings in the perforated sub 5 and the limited release rate of the formation water, it is easy for the formation water to not be fully released when passing through the perforated sub 5, and continue to move downward to the first target layer 8, and eventually be sucked out again by the inner tube 3. However, after the cannula seal 6 is installed, the reinjected formation water that has not been fully released will be blocked by the cannula seal 6 and cannot flow back to the first target layer 8. This is why the cannula seal 6 is located below the perforated sub 5. This configuration effectively improves the efficiency of formation water reinjection and reduces unnecessary workflow.

[0055] In some embodiments, the tubing structure that can meet the simultaneous reinjection of produced water from a single well also includes: a production casing 1 and a packer; the production casing 1 is sleeved on the outside of the outer pipe 2, and the production casing 1 is provided with a water outlet at a position corresponding to the second target layer 9, and the reinjected water released at the perforated sub 5 is released into the second target layer 9 through the water outlet; the packer includes an upper packer 4 and a lower packer 7, and the upper packer 4 and the lower packer 7 are both sleeved on the outer pipe 2, the upper packer 4 is provided above the perforated sub 5, and the lower packer 7 is provided below the perforated sub 5, and the upper packer 4 and the lower packer 7 confine the formation water released from the perforated sub 5 between the upper packer 4 and the lower packer 7.

[0056] Specifically, the production casing 1 is sleeved on the outside of the outer pipe 2, and the production casing 1 can provide wellbore protection, wellbore wall support, etc. The upper packer 4 and the lower packer 7 are set in the area between the inner wall of the production casing 1 and the outer wall of the outer pipe 2, and the set position is sealed. It can also be understood that the production casing 1 and the outer pipe 2 are connected by the packer. The upper packer 4, the lower packer 7, the inner wall of the production casing 1 and the outer wall of the outer pipe 2 constitute the release space of the formation water, and the release space corresponds to the position of the second target layer 9. The perforated short section 5 and the cannula seal 6 are both in the corresponding positions of the release space.

[0057] During operation, the perforating sub 5 releases formation water, which is then released into the production casing 1. If no packer is provided, the released formation water will flow downward back to the first target layer 8. The provision of the lower packer 7 can effectively prevent the formation water released by the perforating sub 5 from remaining in the first target layer 8. At the same time, the release of the formation water released by the perforating sub 5 from the hole provided on the production casing 1 into the second target layer 9 is a relatively slow process. The formation water released by the perforating sub 5 can easily accumulate between the production casing 1 and the outer pipe 2 due to the action of the lower packer. The accumulation of a large amount of formation water may affect the stability of the production casing 1, or the accumulated formation water may surge to the ground and cause losses. Therefore, an upper packer is provided to control the formation water only at a position corresponding to the second target layer 9, and a hole is provided on the production casing 1 at this position to release the reinjected formation water.

[0058] In some embodiments, the tubing structure that can meet the simultaneous reinjection of water produced from a single well also includes: a pressure sensor, which is arranged in the release space, for detecting the pressure of formation water in the release space, calculating the amount of formation water in the release space by the pressure, and adjusting the power of the injection pump according to the amount of formation water in the release space to prevent the injection rate from being too fast, resulting in damage to the tubing structure that can meet the simultaneous reinjection of water produced from a single well, or the injection rate from being too slow, affecting the working efficiency of formation water reinjection.

[0059] In summary, the present invention extracts formation water from the first target layer 8 through the inner pipe 3, leads the extracted formation water to the surface, and injects the formation water back into the second target layer 9 through the outer pipe 2 via a water injection pump installed on the surface. During the injection process, the injected formation water is released through the perforated sub 5 installed at the corresponding position of the outer pipe 2 and the second target layer. At the same time, the cannula seal 6 is set below the perforated sub 5 and sleeved on the inner pipe 3. The cannula seal 6 blocks the outer pipe 2 and the inner pipe 3 to prevent the injected formation water in the outer pipe 2 from flowing to the pipe mouth of the inner pipe 3 and being extracted back to the surface. The upper packer 4 and the lower packer 7 confine the formation water discharged from the perforated sub 5 to the corresponding position of the second target layer 9 and discharge it through the corresponding water outlet hole on the production casing 1 to prevent the formation water discharged from the perforated sub from rising or flowing back to the first target layer. The utility model directly uses the water-producing well as the reinjection well at the same time, that is, the gas well with strong drainage is separated from the natural gas and formation water by a separator on the ground, so that the water produced by the Cretaceous Brazilian Restructuring Formation and the Bashikiqik Formation is reinjected into the shallow Neogene Kuche Formation of the well, effectively reducing the cost of formation water reinjection.

[0060] The above content is only for explaining the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A tubing string device capable of simultaneously reinjecting produced water from a single well, characterized in that: It comprises a production casing (1), wherein an outer tube (2) is inserted into the production casing (1), and an inner tube (3) is inserted into the outer tube (2); An upper packer (4) and a lower packer (7) are provided between the production casing (1) and the outer pipe (2); a cannula seal (6) is provided between the outer pipe (2) and the inner pipe (3); a plurality of drainage holes are provided on the outer pipe (2); the drainage holes are located between the upper packer (4) and the lower packer (7); the cannula seal (6) is located below the plurality of drainage holes; a water outlet hole and a water inlet hole are provided on the production casing (1); the water outlet hole is located between the upper packer (4) and the lower packer (7); and the water inlet hole is located below the lower packer (7).

2. The tubing string device capable of simultaneously reinjecting produced water from a single well according to claim 1, characterized in that: The production casing (1), outer pipe (2) and inner pipe (3) are coaxially arranged.

3. The tubing string device capable of simultaneously reinjecting produced water from a single well according to claim 2, characterized in that: The outer tube (2) is sleeved with a perforated short section (5), and the perforated short section (5) is provided with a plurality of drainage holes.

4. The tubing string device capable of simultaneously reinjecting produced water from a single well according to claim 2, characterized in that: There is a gap between the production casing (1) and the outer pipe (2), and there is a gap between the outer pipe (2) and the inner pipe (3).

5. The tubing string device capable of simultaneously reinjecting produced water from a single well according to claim 1, characterized in that: The cannula seal (6) is located between the perforated nipple (5) and the lower packer (7).

6. The tubing string device capable of simultaneously reinjecting produced water from a single well according to claim 1, characterized in that: The top outlet of the inner tube (3) is flush with the top inlet of the outer tube (2).

7. The tubing string device capable of simultaneously reinjecting produced water from a single well according to claim 1, characterized in that: The top outlet of the inner tube (3) is higher than the top inlet of the outer tube (2).

8. The tubing string device capable of simultaneously reinjecting produced water from a single well according to claim 1, characterized in that: The top outlet of the inner tube (3) is connected to a water storage device.

9. The tubing string device capable of simultaneously reinjecting produced water from a single well according to claim 1, characterized in that: The top inlet of the outer tube (2) is connected to the outlet of the water injection pump, and the inlet of the water injection pump is connected to the water storage device.

10. The tubing string device capable of simultaneously reinjecting produced water from a single well according to claim 1, characterized in that: A pressure sensor is provided between the production casing (1) and the outer pipe (2), and the pressure sensor is connected to a data collection component.

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