Horizontal well breathing type production tubular column capable of producing sand moderately and oil extraction method

Abstract

The invention discloses a proper sand production horizontal well breathing type production pipe column and an oil extraction method.The production pipe column comprises an oil pipe, a branch pipe, a punching oil pipe and an electric pump unit, the oil pipe is hung in a sleeve through an oil pipe hanger, a packer is arranged on the oil pipe and used for packing the sleeve, and a deflation valve is arranged on the packer; the Y-TOOL is connected to the lower part of the oil pipe, and is connected with the electric pump unit and the branch pipe; a hydraulic control sliding sleeve is arranged on the branch pipe and used for controlling opening and closing of the branch pipe. A punching oil pipe is arranged on the horizontal well section and penetrates through the whole perforation sand prevention section, and the tail end of the branch pipe is connected with the punching oil pipe. According to real-time production condition monitoring, the opening or closing state of the branch pipe channel is controlled through the hydraulic control pipeline by adopting the pressing or pressure relief action, and positive circulation sand washing of the shaft, stratum washing and blockage removal and recovery of the productivity of the oil production well can be achieved without steel wire operation and pump starting and stopping operation. The method reduces the influence of frequent pump starting and stopping, shaft pressure change and the like on the lifting performance of the electric pump unit.

Description

Technical Field

[0001] The present invention relates to the technical field of oil production operations, and in particular to a breathing production string for a moderately sanded horizontal well and an oil production method. Background Art

[0002] Existing horizontal wells generally use electric pump production strings for oil production operations, and the electric pump unit is hung at a position above 60 degrees of well inclination. There are the following defects: (1) In muddy and loose reservoirs, the migration of particles or mud and sand will cause the long horizontal section of the wellbore to be buried by mud and sand or blocked in the near-wellbore area, affecting the oil well production capacity; (2) The existing production string cannot be used for long horizontal section wellbore circulation sand flushing; (3) The existing production string adopts the design of working barrel and Y plug, and the pump hanging position of the electric pump unit cannot meet the production requirements of well inclination greater than 60 degrees; (4) In the process of unblocking the formation, the electric pump unit's lifting electrical performance is easily damaged by the start-stop pump, wellbore pressure and flow rate changes, resulting in well lying. It is often necessary to restore oil well production through well repair operations. In addition, it is difficult to flush and unblock the horizontal section of the wellbore. The traditional production string design and well repair operation method are not effective, which greatly limits the release of production capacity of muddy and loose reservoirs. Summary of the Invention

[0003] The purpose of this application is to provide a breathing production string and oil production method for a horizontal well with moderate sand production, so as to solve the problems raised in the above background technology.

[0004] To achieve the above objectives, this application provides the following technical solutions:

[0005] A breathing production string for a moderately sanding horizontal well comprises an oil pipe, a branch pipe, a perforated oil pipe and an electric pump unit. The oil pipe is hung in a casing by a oil pipe hanger. A packer is provided on the oil pipe, which is used to isolate the casing and is provided with an air release valve. A Y-TOOL is connected to the bottom of the oil pipe, and the Y-TOOL is connected to the electric pump unit and the branch pipe. A hydraulically controlled sliding sleeve is provided on the branch pipe, and the hydraulically controlled sliding sleeve is used to control the opening and closing of the branch pipe. A perforated oil pipe is set in the horizontal well section to pass through the entire perforation and sand control section, and the end of the branch pipe is connected to the perforated oil pipe.

[0006] Optionally, the outlet of the electric pump unit is provided with a check valve.

[0007] Optionally, a self-resetting check valve is installed at the end of the perforated oil pipe, and the self-resetting check valve is connected to the perforated oil pipe through an oil pipe thread.

[0008] Optionally, a pipe shoe is installed on the perforated oil pipe below the self-resetting check valve through the oil pipe thread.

[0009] Optionally, the hydraulic control sleeve adopts an outer cover type single-line hydraulic control sleeve.

[0010] Optionally, the branch pipe includes a first branch pipe and a second branch pipe arranged in sequence, the outer cover type single-pipeline hydraulic control sleeve is installed between the first branch pipe and the second branch pipe, and the outer cover type single-pipeline hydraulic control sleeve is located below the bottom depth position of the electric pump unit; the hydraulic control pipeline of the outer cover type single-pipeline hydraulic control sleeve extends to the wellhead, and the outer cover type single-pipeline hydraulic control sleeve is opened or closed at the wellhead by pressurizing or releasing pressure.

[0011] An oil production method for the aforementioned moderate sand production horizontal well breathing production string comprises the following steps:

[0012] Create the aforementioned horizontal well breathing production string;

[0013] During the pump start-up period, the hydraulic control sleeve controls the branch pipe passageway, and the well fluid is lifted to the wellhead by the electric pump unit. Based on the oil well production monitoring situation, the oil production system is adjusted, and a breathing sand flushing and blockage removal cycle is formulated.

[0014] In the mid-production stage, if the wellbore is buried by mud and sand or the area near the wellbore is blocked, adjust the production frequency of the electric pump unit and reduce the lifting head;

[0015] Keep the air release valve fully open. After the hydraulic control sleeve controls the branch pipe to open, adopt the tubing positive circulation flushing method. The flushing fluid flows through the tubing, branch pipe, hydraulic control sleeve, and flows out from the horizontal section of the perforated tubing to flush the mud and sand in the wellbore. The mud and sand are mixed with the flushing fluid and returned to the surface through the casing and tubing annulus. If the positive circulation is blocked, reverse circulation is used to flush the well and flush the sand. The flushing fluid enters from the casing, passes through the air release valve, packer, annulus A, sand control string and perforated tubing annulus, self-resetting check valve and perforated tubing, and enters the tubing. The mud, sand and flushing fluid are returned to the surface from the tubing.

[0016] Adjust the opening of the bleed valve. After the hydraulically controlled sliding sleeve controls the branch pipe to open, the unblocking fluid flows through the tubing, branch pipe, and hydraulically controlled sliding sleeve using a positive tubing squeeze method, and then flows out from the perforated tubing in the horizontal section, completing flushing and unblocking of the near-wellbore area.

[0017] After the passage of the hydraulically controlled sliding sleeve control branch pipe is closed, the production frequency of the electric pump unit is restored, the lifting head is increased, and the well fluid is lifted to the wellhead.

[0018] In summary, the technical effects and advantages of the present invention are as follows: the moderately sanding horizontal well breathing production tubing and oil production method of the present invention proposes an efficient working plan for releasing the production capacity of oil wells in mud-rich and loose reservoirs, solves the problem of long horizontal sections of wellbores being buried by mud and sand or being blocked in the near-wellbore area, affecting the production capacity of oil wells, avoids the problem of electric pump units being affected by the start-stop pump, wellbore pressure and flow rate changes affecting the lifting electrical performance, resulting in lying wells, reduces the cost of moving tubing string well repair operations, and has better benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 This is a schematic structural diagram of a horizontal well breathing production string in one embodiment of the present invention;

[0021] Figure 2 Schematic diagram of the flow of an oil production method in one embodiment of the present invention.

[0022] Among them: 1. Packer; 2. Hydraulic control sliding sleeve; 3. Downhole safety valve; 4. Air release valve; 5. Oil pipe; 6. Electric pump unit; 7. Perforated oil pipe; 8. Self-resetting check valve; 9. Casing; 10. Y-TOOL; 11. Branch pipe; 12. Pipe shoe; 13. First branch pipe; 14. Second branch pipe; 15. Sand control string. DETAILED DESCRIPTION

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0024] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0025] This embodiment proposes a breathing production string for horizontal wells with moderate sand production, such as Figure 1 As shown, the system includes a tubing, branch pipes, perforated tubing, and an electric pump unit. The tubing is suspended within the casing via a tubing hanger. A packer is installed on the tubing to isolate the casing and is equipped with a bleed valve. A Y-TOOL is connected below the tubing, connecting the electric pump unit and the branch pipe. The outlet of the electric pump unit is equipped with a check valve to prevent backflow of well fluid. The Y-TOOL, also known as a Y-connector, is a commercially available product. A hydraulically controlled sliding sleeve is installed on the branch pipe to control its opening and closing. Perforated tubing is installed in the horizontal well section, running through the entire perforation and sand control section. The end of the branch pipe is connected to the perforated tubing. A self-resetting check valve and a pipe shoe are connected below the perforated tubing.

[0026] In this embodiment, a self-resetting check valve is installed at the end of the perforated tubing, connected to the perforated tubing via tubing threads. This self-resetting check valve is a commercially available product that allows liquid outside the perforated tubing to flow into the tubing through the valve, but prevents liquid inside the tubing from flowing out of the tubing through the valve. The valve ball of the self-resetting check valve can be reset in horizontal well sections.

[0027] In this embodiment, a pipe shoe is installed on the perforated tubing below the self-resetting check valve through the tubing thread. The perforated tubing in the horizontal well section adopts the method of perforation and tubing thread connection. The perforated tubing includes multiple sections of tubing that are sequentially threaded. For example, according to 2-7 / 8″ tubing, the depth of the tubing is 2100m, the tail end of the tubing is blocked, and the flushing displacement is 30m 3 / h (i.e. 720m 3 / d), every 60 meters of oil pipe is perforated for simulation, and the flow rate of the first perforated oil pipe is 74.7m 3 / d, gradually decreasing to the tenth group of perforated oil pipes with a flow rate of 70.8m 3 / d, basically every section can discharge water evenly.

[0028] Specifically, in this embodiment, the hydraulic control sleeve employs a single-line, outer-cover hydraulic control sleeve. This type of sleeve is commercially available. When ground hydraulic pressure applies pressure to the hydraulic control sleeve, the sleeve remains open, thereby opening the branch pipe channel. When the ground hydraulic pressure is released, the sleeve automatically closes, thereby closing the branch pipe channel.

[0029] The branch pipe includes a first branch pipe and a second branch pipe arranged in sequence, the outer cover type single-pipeline hydraulic control sleeve is installed between the first branch pipe and the second branch pipe, and the outer cover type single-pipeline hydraulic control sleeve is located below the bottom depth position of the electric pump unit; the hydraulic control pipeline of the outer cover type single-pipeline hydraulic control sleeve extends to the wellhead, and the outer cover type single-pipeline hydraulic control sleeve is opened or closed by pressurizing or releasing pressure at the wellhead. Pressurizing or releasing pressure on the hydraulic control pipeline to open or close the outer cover type single-pipeline hydraulic control sleeve belongs to the existing technology.

[0030] This embodiment also provides an oil production method for the aforementioned moderate sand production horizontal well breathing production string, such as Figure 1 and 2 As shown, the following steps are included:

[0031] 1) Create the aforementioned horizontal well breathing production string; hang the production tubing in the casing with a tubing hanger, isolate the casing with a packer, and install an air release valve; connect the Y-TOOL, electric pump unit, and branch pipe below the tubing, with a check valve at the outlet of the electric pump unit to prevent backflow of well fluid; install an external cover single-line hydraulic control sliding sleeve on the branch pipe; in the horizontal well section, use perforated tubing to penetrate the entire perforated sand control section, and connect a self-resetting check valve and pipe shoe below the perforated tubing;

[0032] 2) During the pump start-up period, the hydraulic control sleeve controlled the branch pipe passageway, specifically, the hydraulic control line of the outer cover single-line hydraulic control sleeve was in a depressurized state, blocking the branch pipe flow channel below the Y-TOOL. The well fluid was lifted to the wellhead by the electric pump unit. Based on the oil well production monitoring conditions, such as the drop in bottomhole pressure, current fluctuation, and fluid production parameters, as well as the monitoring of sand and mud production at the wellhead, a dynamic analysis was conducted to determine whether there was blockage in the near-wellbore area or wellbore. The oil production system was adjusted in a timely manner, and a breathing sand flushing and blockage removal cycle was established.

[0033] 3) In the mid-production stage, due to the migration of fine particles or mud and sand in loose muddy reservoirs, the wellbore may be buried in mud and sand, or the near-wellbore area may be blocked, affecting the production capacity of the oil well. By adjusting the production frequency of the electric pump unit and reducing the lifting head, such as 15HZ low-frequency operation, opening the air valve, and controlling the flow rate of the A annulus liquid, i.e., the flushing fluid, the motor can be cooled, and operations such as tubing positive circulation sand flushing and formation flushing and unblocking can be carried out without stopping the pump; the A annulus refers to the annular space between the production tubing and the production casing;

[0034] 4) Keep the bleed valve fully open. After the channel of the hydraulic control sleeve controlling the branch pipe is opened, specifically pressurize the hydraulic control pipeline on the ground to open the channel of the outer cover type single-line hydraulic control sleeve. Then, adopt the positive circulation flushing method of the tubing. The flushing fluid flows through the tubing, branch pipe, outer cover type single-line hydraulic control sleeve, and flows out evenly from the horizontal section of the perforated tubing at a certain flow rate to flush the mud and sand in the wellbore. The mud and sand are mixed with the flushing fluid and returned to the ground from the casing and tubing annulus. For wellbore sand flushing, the positive circulation flushing method is preferred to avoid damage to the electric pump system. If the positive circulation is blocked, try reverse circulation well washing and sand flushing. That is, the flushing fluid enters from the casing, passes through the packer bleed valve, A annulus, sand control string and perforated tubing annulus, self-resetting check valve and perforated tubing, and enters the inside of the tubing. Mud and sand and flushing fluid are returned to the ground from the tubing.

[0035] 5) Adjust the opening of the bleed valve. After the channel of the hydraulic control sleeve controlling the branch pipe is opened, the hydraulic control pipeline is pressurized on the ground. After the channel of the outer cover single pipeline hydraulic control sleeve is opened, the unblocking fluid flows through the oil pipe, branch pipe, and outer cover single pipeline hydraulic control sleeve by positive squeezing of the tubing. It flows out of the perforated tubing in the horizontal section at a certain flow rate and enters the formation, completing the flushing and unblocking of the area near the wellbore and restoring the oil well production capacity.

[0036] 6) After the hydraulic control sleeve closes the branch pipe channel, the hydraulic control line pressure is released. After the cover-type single-line hydraulic control sleeve channel is closed, the production frequency of the electric pump unit is restored, the lifting head is increased, and the well fluid is lifted to the wellhead, achieving horizontal well breathing oil production. The surface sand removal process is applied to production sand removal, multiphase fluid sand removal, and crude oil sand removal, with a sand removal rate of over 98% for particles of 5-6 microns.

[0037] In summary, this embodiment has the following technical effects and advantages:

[0038] 1) The branch pipe channel is hydraulically controlled, eliminating the need for additional wireline operations to remove blockages. Compared with traditional methods, the operation time is higher and the oil well production rate is improved;

[0039] 2) It is suitable for the migration of fine particles or mud and sand in loose muddy reservoirs and other types of reservoirs. It is more applicable to wellbores with long water sections, and can achieve wellbore sand flushing and near-wellbore area flushing and blockage removal, thereby restoring oil well productivity;

[0040] 3) Effectively avoid starting and stopping the pump, changes in wellbore pressure and flow rate, which may cause the electric pump unit to lose its electrical performance and lie in the well;

[0041] 4) Effectively reduce the cost of moving tubing string workover operations, and improve the quality and efficiency of oil well production and operation and maintenance.

[0042] For ease of description, spatially relative terms such as "upper," "lower," "outer," and "inner" are used in the embodiments to describe the relationship of one element or feature relative to another element or feature shown in the figures. It should be understood that these spatial terms are intended to encompass different orientations of the device during use or operation in addition to the orientation shown in the figures. Thus, the exemplary term "lower" encompasses both upper and lower orientations.

[0043] Furthermore, relational terms such as "3" and "4" etc. are merely used to distinguish one component from another having the same name, but do not necessarily require or imply any such actual relationship or order between these components.

[0044] Although the preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments. The above-mentioned specific embodiments are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms of specific changes without departing from the scope of protection of the invention and the claims. These all fall within the scope of protection of the present invention.

Claims

1. A breathing production string for a moderate sand production horizontal well, characterized by: It includes an oil pipe, a branch pipe, a perforated oil pipe and an electric pump unit. The oil pipe is hung in the casing through a oil pipe hanger. A packer is provided on the oil pipe, which is used to isolate the casing and has an air release valve. A Y-TOOL is connected to the bottom of the oil pipe, and the Y-TOOL is connected to the electric pump unit and the branch pipe. A hydraulically controlled sliding sleeve is provided on the branch pipe, and the hydraulically controlled sliding sleeve is used to control the opening and closing of the branch pipe. A perforated oil pipe is set in the horizontal well section to pass through the entire perforation and sand control section, and the end of the branch pipe is connected to the perforated oil pipe.

2. The moderate sand production horizontal well breathing production string according to claim 1, characterized in that: The outlet of the electric pump unit is provided with a check valve.

3. The moderate sand production horizontal well breathing production string according to claim 1, characterized in that: A self-resetting check valve is installed at the end of the perforated oil pipe, and the self-resetting check valve is connected to the perforated oil pipe through an oil pipe thread.

4. The moderate sand production horizontal well breathing production string according to claim 3, characterized in that: A pipe shoe is installed on the perforated oil pipe below the self-resetting check valve through the oil pipe thread.

5. The moderate sand production horizontal well breathing production string according to claim 1, characterized in that: The hydraulic control sliding sleeve adopts an outer cover type single pipeline hydraulic control sliding sleeve.

6. The moderate sand production horizontal well breathing production string according to claim 5, characterized in that: The branch pipe includes a first branch pipe and a second branch pipe arranged in sequence, the outer cover type single-pipeline hydraulic control sliding sleeve is installed between the first branch pipe and the second branch pipe, and the outer cover type single-pipeline hydraulic control sliding sleeve is located below the bottom depth position of the electric pump unit; the hydraulic control pipeline of the outer cover type single-pipeline hydraulic control sliding sleeve extends to the wellhead, and the outer cover type single-pipeline hydraulic control sliding sleeve is opened or closed by pressurizing or releasing pressure at the wellhead.

7. An oil production method for a breathing production string for a moderate sand production horizontal well according to any one of claims 1 to 6, characterized in that: The following steps are involved: Create a horizontal well breathing production string as described in any one of claims 1-6; During the pump start-up period, the hydraulic control sleeve controls the branch pipe passageway, and the well fluid is lifted to the wellhead by the electric pump unit. Based on the oil well production monitoring situation, the oil production system is adjusted, and a breathing sand flushing and blockage removal cycle is formulated. In the mid-production stage, if the wellbore is buried by mud and sand or the area near the wellbore is blocked, adjust the production frequency of the electric pump unit and reduce the lifting head; Keep the bleed valve fully open. After the hydraulically controlled sliding sleeve controls the branch pipe, a positive circulation flushing method is used for the tubing. The flushing fluid flows through the tubing, branch pipe, and hydraulically controlled sliding sleeve, and flows out from the perforated tubing in the horizontal section to flush out the mud and sand in the wellbore. The mud and sand are mixed with the flushing fluid and then returned to the surface through the annulus of the casing and tubing. If the forward circulation is blocked, reverse circulation is used to flush the well and flush the sand. The flushing fluid enters from the casing, passes through the bleed valve, packer, A annulus, sand control string and perforated tubing annulus, self-resetting check valve and perforated tubing, and enters the tubing. The mud, sand and flushing fluid are returned to the surface from the tubing. Adjust the opening of the bleed valve. After the hydraulically controlled sliding sleeve controls the branch pipe to open, the unblocking fluid flows through the tubing, branch pipe, and hydraulically controlled sliding sleeve using a positive tubing squeeze method, and then flows out from the perforated tubing in the horizontal section, completing flushing and unblocking of the near-wellbore area. After the passage of the hydraulically controlled sliding sleeve control branch pipe is closed, the production frequency of the electric pump unit is restored, the lifting head is increased, and the well fluid is lifted to the wellhead.

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