A sliding sleeve single flow valve type anti-flowback steam huff and puff injection string

Abstract

The present application belongs to the technical field of oil production engineering, and discloses a sliding sleeve single-flow valve type anti-backflow steam huff and puff injection pipe column. The sliding sleeve single-flow valve type anti-backflow steam huff and puff injection pipe column comprises, in sequence, an expansion pipe, a heat insulation pipe A, a sliding sleeve type steam injection valve, a heat insulation pipe B, a single-flow valve type steam injection valve, a heat insulation pipe C and a plug, heat-sensitive packers are arranged on the outer walls of the heat insulation pipe A and the heat insulation pipe B, a steam injection channel is arranged in the pipe column, and the problem of energy loss caused by steam entering the steam injection pipe column during the soaking well stage is solved. The sliding sleeve single-flow valve type anti-backflow steam huff and puff injection pipe column can prevent steam from flowing back after steam injection, avoids heat from being scattered in non-production layers, is beneficial to crude oil production, and improves heat utilization rate.

Description

Technical Field

[0001] This invention belongs to the field of oil production engineering technology. It relates to a sliding sleeve single-flow valve type anti-backflow steam injection tubing string. Background Technology

[0002] Shuguang Oilfield currently relies primarily on steam injection for oil production, with staged steam injection being the main method. However, during the well-closing phase, the lack of a shut-off valve allows steam to flow back into the tubing, causing heat to dissipate into non-productive layers and resulting in significant energy loss. Although nitrogen injection insulation technology is employed, it is currently only used in the annulus, and inadequate sealing leads to poor insulation performance. Insulating jackets are used on the surface, but due to frequent use and improper installation, some energy is lost, hindering crude oil production. Summary of the Invention

[0003] To overcome the shortcomings of existing technologies, this invention provides a sliding-sleeve single-flow valve type anti-backflow steam injection string, solving the problem of energy loss caused by steam entering the injection string during the well-closing stage. It prevents steam backflow after injection, avoiding heat dissipation in non-producing formations, which is beneficial to crude oil production and improves heat utilization.

[0004] The above-mentioned objective of this invention is achieved through the following technical solution: A sliding-sleeve single-flow valve type anti-backflow steam injection column includes a telescopic pipe, a heat insulation pipe A, a sliding-sleeve steam injection valve, a heat insulation pipe B, a single-flow valve type steam injection valve, a heat insulation pipe C, and a plug connected in sequence; the outer walls of the heat insulation pipe A and the heat insulation pipe B are respectively provided with thermally sensitive packers; the column is provided with a steam injection channel; The sliding sleeve type steam injection valve includes a valve body A, with an internal channel for the main steam injection channel. A sliding sleeve is located in the central area of ​​the valve body A. The sliding sleeve is connected to the valve body A by a shear pin. A ball seat is located inside the sliding sleeve. The ball seat is connected to the sliding sleeve by a locking pin. Holes are opened at the upper and lower ends of the valve body A, respectively, and these holes connect to the steam injection channel A. Two steam injection channels A are provided. A valve seat A is located inside the steam injection channel A, and a valve cover A is located at the end of the steam injection channel A. A valve cover A is located between the valve cover A and the valve seat A. The sliding sleeve type steam injection valve is also equipped with a valve ball C. The sliding sleeve and the hole on valve body A are in relative movable contact connection; when valve ball C enters the main steam injection channel from the tubing string; valve ball C contacts the ball seat, and when the pressure reaches the shearing pressure of the shearing pin, the sliding sleeve slides down; the sliding sleeve and the hole on valve body A are no longer in contact connection; the main steam injection channel is connected to the steam injection channel A; The single-flow steam injection valve includes a valve body B, with an internal channel of the valve body B being the main steam injection channel. Holes are opened at the upper and lower ends of the valve body B, which are connected to the steam injection channels B respectively. There are two steam injection channels B. A valve seat B is provided inside the steam injection channel B, and a valve cover B is provided at the end of the steam injection channel B. A valve cover B is provided between the valve cover B and the valve seat B.

[0005] Furthermore, the telescopic tube is connected to the heat insulation tube A via a threaded connection; Furthermore, the thermal packer is located in the middle area of ​​the outer wall of the insulation tube A; there are two thermal packers, and the two are symmetrically arranged relative to the axis of the tube column; the thermal packer is located in the middle area of ​​the outer wall of the insulation tube B; there are two thermal packers, and the two are symmetrically arranged relative to the axis of the tube column. Furthermore, the steam injection channel B is L-shaped.

[0006] Furthermore, valve seat B is fixedly installed inside steam injection channel B.

[0007] Furthermore, valve body B has an internal thread at one end and an external thread at the other end; the internal and external threads are provided for connection with other adjacent components.

[0008] Furthermore, valve body A has an internal thread at one end and an external thread at the other end; the internal and external threads are provided for connection with other adjacent components.

[0009] Furthermore, the steam injection channel A is L-shaped.

[0010] Furthermore, valve seat A is fixedly installed inside steam injection channel A.

[0011] The advantages of this invention compared to the prior art are: This invention provides a sliding-sleeve single-flow valve type anti-backflow steam injection string, which can prevent steam backflow after injection, avoiding heat dissipation in non-producing formations, thus benefiting crude oil production and improving heat utilization. Using this invention's string does not increase the difficulty of well operations, reduces the surface temperature of the injection wellhead, and increases single-well cycle oil production by 20 tons. Attached Figure Description

[0012] The invention will be further described below with reference to the accompanying drawings. Figure 1 This is a schematic diagram of the sliding sleeve single-flow valve type anti-backflow steam injection pipe string of the present invention.

[0013] Figure 2 This is a cross-sectional view of a single-flow steam injection valve.

[0014] Figure 3 Cross-sectional view of a sliding sleeve type steam injection valve.

[0015] In the diagram: 1. Telescopic pipe, 2. Thermally sensitive packer A, 3. Sliding sleeve type steam injection valve, 4. Thermally sensitive packer B, 5. One-way valve type steam injection valve, 6. Plug, 7. Insulation pipe A, 8. Insulation pipe B, 9. Insulation pipe C, 301. Valve body A, 302. Steam injection passage A, 303. Valve seat A, 304. Valve ball A, 305. Valve cover A, 306. Sealing ring, 307. Set pin, 308. Ball seat, 309. Valve ball C, 310. Sliding sleeve, 501. Valve body B, 502. Main steam injection passage, 503. Steam injection passage B, 504. Valve seat B, 505. Valve ball B, 506. Valve cover B. Detailed Implementation

[0016] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] The present invention is described in detail below through specific embodiments, but this does not limit the scope of protection of the present invention. Unless otherwise specified, the experimental methods used in the present invention are all conventional methods, and the experimental equipment, materials, reagents, etc. used can all be obtained commercially.

[0018] In the description of this invention, it should be noted that the terms "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used only for distinction and should not be construed as indicating or implying relative importance.

[0019] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0020] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. Example

[0021] A sliding-sleeve single-flow valve type anti-backflow steam huff and puff injection tubing, such as Figures 1-3As shown, the tube column includes, in sequence, a telescopic tube 1, a heat insulation tube A 7, a sliding sleeve steam injection valve 3, a heat insulation tube B 8, a one-way valve steam injection valve 5, a heat insulation tube C 9, and a plug 6; the outer walls of the heat insulation tube A 7 and the heat insulation tube B 8 are respectively equipped with thermally sensitive packers; the tube column is equipped with a steam injection channel. The sliding sleeve type steam injection valve 3 includes a valve body A 301, with an internal channel for the main steam injection channel. A sliding sleeve 310 is located in the central area of ​​the valve body A 301. The sliding sleeve 310 is connected to the valve body A 301 by a shear pin. A ball seat 308 is located inside the sliding sleeve 310. The ball seat 308 is connected to the sliding sleeve 310 by a locking pin 307. Holes are opened at the upper and lower ends of the valve body A 301, respectively, to connect to the steam injection channel A 302. Two steam injection channels A 302 are provided. A valve seat A 303 is located inside the steam injection channel A 302. A valve cover A 305 is located at the end of the steam injection channel A 302, and a valve cover A 305 is positioned between the valve cover A 305 and the valve seat A 303. The sliding sleeve type steam injection valve 3 is also equipped with a valve ball C 309. The sliding sleeve 310 and the valve body A 301 are connected to the main channel. The hole on 301 is for relative movable contact connection; when the valve ball C 309 enters the main steam injection channel from the tubing string; the valve ball C 309 contacts the ball seat 308, and when the pressure reaches the shearing pressure of the shearing pin, the sliding sleeve 310 slides down; the sliding sleeve 310 and the hole on the valve body A 301 are no longer in contact connection; the main steam injection channel is connected to the steam injection channel A 302; The single-flow steam injection valve 5 includes a valve body B 501, with a main steam injection channel 502 inside the valve body B 501. Holes are opened at the upper and lower ends of the valve body B 501, which are respectively connected to the steam injection channels B 503. Two steam injection channels B 503 are provided. A valve seat B 504 is provided inside the steam injection channel B 503. A valve cover B 506 is provided at the end of the steam injection channel B 503. The valve cover B 506 is located between the valve seat B 504 and the valve cover B 506.

[0022] Furthermore, the telescopic tube 1 is connected to the heat insulation tube A 7 via a threaded connection; Furthermore, the thermal packer is located in the middle area of ​​the outer wall of the insulation tube A7; there are two thermal packers, and the two are symmetrically arranged relative to the axis of the tube column; the thermal packer is located in the middle area of ​​the outer wall of the insulation tube B8; there are two thermal packers, and the two are symmetrically arranged relative to the axis of the tube column. Furthermore, the steam injection channel B 503 is L-shaped.

[0023] Furthermore, valve seat B 504 is fixedly installed inside steam injection passage B 503.

[0024] Furthermore, valve body B 501 has an internal thread at one end and an external thread at the other end; the internal and external threads are provided for connection with other adjacent components.

[0025] Furthermore, valve body A 301 has an internal thread at one end and an external thread at the other end; the internal and external threads are provided for connection with other adjacent components.

[0026] Furthermore, the steam injection channel A 302 is L-shaped.

[0027] Furthermore, valve seat A 303 is fixedly installed inside steam injection passage A 302. The specific working process of the above-mentioned sliding sleeve single-flow valve type anti-backflow steam huff and puff injection tubing is as follows: During operation, after the sliding sleeve single-flow valve type anti-backflow steam injection string is lowered into the wellbore to the corresponding working position, steam is injected into the string to set the thermal packer. At this time, the steam is injected into the target layer through the steam injection channel B 503 of the single-flow valve type steam injection valve 5.

[0028] After sufficient steam is injected to the design quantity, valve ball C 309 is inserted into the tubing. When the pressure reaches the shearing pressure of the shear pin, slide 310 slides down, opening the steam injection channel A 302. At this time, steam passes through valve ball A 304 and valve cover A 305 to inject the designed steam into the target layer.

[0029] At this time, the valve ball C 309, the ball seat 308, and the sliding sleeve 310 are in common circumferential action. At this time, the pressure on the upper part of the valve ball B 505 is less than the pressure on the lower part. At this time, the valve ball B 505 is in close contact with the valve seat B 504 under the action of the steam below, so that the steam injected into the target layer cannot be backflowed.

[0030] This ensures the amount of steam injected into the target layer, which is beneficial for crude oil production. When the sliding steam injection valve 3 reaches the designed amount of steam, the injection of steam into the tubing stops. At this time, the pressure inside the tubing is less than the pressure outside the tubing. Under the action of the steam, the valve ball A 304 and the valve seat A 303 are in close contact, preventing steam in the target layer from entering the tubing.

[0031] Because the amount of steam inside the tubing is much less than that in a conventional steam injection tubing, steam waste is reduced. This is beneficial for crude oil production and reduces heat transfer to non-productive layers.

[0032] When the well in the production zone has been shut down for a certain period of time, as the temperature decreases, the thermal packer retracts, allowing the annular space of the oil and casing to be connected vertically. When the annular space of the oil and casing is lowered to a level suitable for tubing string operation, the steam injection tubing string is pulled out and the production tubing string is lowered in, and the crude oil officially enters the production stage. Application Example 1 The specific application example of the sliding sleeve single-flow valve type anti-backflow steam huff and puff injection tubing provided in Example 1 in actual production is as follows: During operation, after the sliding sleeve single-flow valve type anti-backflow steam injection string is lowered into the wellbore to the corresponding working position, steam is injected into the string to set the thermal packer. At this time, the steam is injected into the target layer through the steam injection channel B 503 of the single-flow valve type steam injection valve 5.

[0033] After sufficient steam is injected to the design quantity, valve ball C 309 is inserted into the tubing. When the pressure reaches the shearing pressure of the shear pin, slide 310 slides down, opening the steam injection channel A 302. At this time, steam passes through valve ball A 304 and valve cover A 305 to inject the designed steam into the target layer.

[0034] At this time, the valve ball C 309, the ball seat 308, and the sliding sleeve 310 are in common circumferential action. At this time, the pressure on the upper part of the valve ball B 505 is less than the pressure on the lower part. At this time, the valve ball B 505 is in close contact with the valve seat B 504 under the action of the steam below, so that the steam injected into the target layer cannot be backflowed.

[0035] This ensures the amount of steam injected into the target layer, which is beneficial for crude oil production. When the sliding steam injection valve 3 reaches the designed amount of steam, the injection of steam into the tubing stops. At this time, the pressure inside the tubing is less than the pressure outside the tubing. Under the action of the steam, the valve ball A 304 and the valve seat A 303 are in close contact, preventing steam in the target layer from entering the tubing.

[0036] Because the amount of steam inside the tubing is much less than that in a conventional steam injection tubing, steam waste is reduced. This is beneficial for crude oil production and reduces heat transfer to non-productive layers.

[0037] When the well in the production zone has been shut down for a certain period of time, as the temperature decreases, the thermal packer retracts, allowing the annular space of the oil and casing to be connected vertically. When the annular space of the oil and casing is lowered to a level suitable for tubing string operation, the steam injection tubing string is pulled out and the production tubing string is lowered in, and the crude oil officially enters the production stage.

[0038] Shu 1-38-K044, in the previous cycle, conventional layered steam injection was used. The first layer injected 1200 cubic meters of steam at a pressure of 11 MPa, and the second layer injected 800 cubic meters of steam at a pressure of 9 MPa. During the well-clogging stage, the wellhead temperature was maintained between 100-360 degrees Celsius. However, due to the action of the downhole packer, the temperature of the annular space of the casing was the same as that of the outside. In the previous cycle, it produced 800 tons of oil in 100 days. In this cycle, the same tubing string was used. The first layer injected 1100 cubic meters of steam at a pressure of 11 MPa, and the second layer injected 900 cubic meters of steam at a pressure of 8.5 MPa. During the well-clogging stage, the wellhead temperature was maintained between 40-70 degrees Celsius. In this cycle, it has produced 912 tons of oil in 110 days, achieving the expected results. The present invention provides a sliding sleeve single-flow valve type anti-backflow steam injection string, which can prevent steam backflow after steam injection, avoid heat dissipation in non-productive layers, benefit crude oil production, and improve heat utilization.

[0039] The embodiments described above are merely preferred embodiments of the present invention, and not all feasible embodiments of the present invention. For those skilled in the art, any obvious modifications made without departing from the principles and spirit of the present invention should be considered to be included within the scope of protection of the claims. Although the present invention has been described above with reference to embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the present invention. In particular, as long as there is no technical conflict, the features in the embodiments disclosed in the present invention can be combined with each other in any way. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A sliding-sleeve single-flow valve type anti-backflow steam huff and puff injection string, characterized in that, The tube column includes, in sequence, a telescopic tube (1), a heat insulation tube A (7), a sliding steam injection valve (3), a heat insulation tube B (8), a single-flow steam injection valve (5), a heat insulation tube C (9), and a plug (6); the outer walls of the heat insulation tube A (7) and the heat insulation tube B (8) are respectively equipped with heat-sensitive packers; the tube column is equipped with a steam injection channel; The sliding sleeve type steam injection valve (3) includes a valve body A (301), the internal channel of the valve body A (301) is the main steam injection channel, and a sliding sleeve (310) is provided in the central area of ​​the valve body A (301); the sliding sleeve (310) is connected to the valve body A (301) by a shear pin; a ball seat (308) is provided inside the sliding sleeve (310); the ball seat (308) is connected to the sliding sleeve (310) by a set pin (307); holes are opened at the upper and lower ends of the middle of the valve body A (301), and the holes are respectively connected to the steam injection channel A (302); two steam injection channels A (302) are provided; a valve seat A (303) is provided inside the steam injection channel A (302), and the steam injection channel... The end of channel A (302) is provided with valve cover A (305), and valve cover A (305) is provided between valve seat A (303); the sliding steam injection valve (3) is also equipped with valve ball C (309); the sliding sleeve (310) and the hole opened on the valve body A (301) are in relative movable contact connection; when the valve ball C (309) enters the main steam injection channel from the tubing; the valve ball C (309) contacts the ball seat (308), and when the pressure reaches the shearing pressure of the shearing pin, the sliding sleeve (310) slides down; the sliding sleeve (310) and the hole opened on the valve body A (301) are no longer in contact connection; the main steam injection channel is connected to the steam injection channel A (302); The single-flow steam injection valve (5) includes a valve body B (501), the internal channel of the valve body B (501) is the main steam injection channel (502), and holes are opened at the upper and lower ends of the valve body B (501) respectively, which are connected to the steam injection channels B (503); two steam injection channels B (503) are provided; a valve seat B (504) is provided inside the steam injection channel B (503), and a valve cover B (506) is provided at the end of the steam injection channel B (503), and a valve cover B (506) is provided between the valve cover B (506) and the valve seat B (504); The telescopic tube (1) is connected to the heat insulation tube A (7) by a thread; The thermal packer is set in the middle area of ​​the outer wall of the heat insulation tube A (7); there are two thermal packers, and the two are symmetrically arranged relative to the axis of the tube column.

2. The sliding sleeve single-flow valve type anti-backflow steam huff and puff injection string as described in claim 1, characterized in that, Steam injection channel B (503) is L-shaped.

3. The sliding sleeve single-flow valve type anti-backflow steam injection string as described in claim 2, characterized in that, Valve seat B (504) is fixedly installed inside the steam injection channel B (503).

4. The sliding sleeve single-flow valve type anti-backflow steam injection string as described in claim 3, characterized in that, The valve body B (501) has an internal thread at one end and an external thread at the other end; the internal and external threads are provided for connection with other adjacent components.

5. A sliding-sleeve single-flow valve type anti-backflow steam injection string as described in claim 4, characterized in that, The valve body A (301) has an internal thread at one end and an external thread at the other end; the internal and external threads are provided for connection with other adjacent components.

6. The sliding sleeve single-flow valve type anti-backflow steam injection string as described in claim 5, characterized in that, Steam injection channel A (302) is L-shaped.

7. A sliding-sleeve single-flow valve type anti-backflow steam injection string as described in claim 6, characterized in that, Valve seat A (303) is fixedly installed inside the steam injection channel A (302).

8. A sliding-sleeve single-flow valve type anti-backflow steam injection string as described in claim 7, characterized in that, The thermal packer is set in the middle area of ​​the outer wall of the heat insulation tube B (8); there are two thermal packers, and the two are symmetrically arranged relative to the axis of the tube column.

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