A screen pipe for sand control completion of a heavy oil thermal recovery well and a use method thereof

Abstract

The present application relates to the technical field of oil exploitation, in particular to a screen pipe for sand prevention and completion of heavy oil thermal recovery well and a use method thereof. The technical scheme is that a valve body is arranged on the upper inner side of the screen pipe, a valve core installation groove is arranged in the middle of the valve body, a valve core is installed in the valve core installation groove, springs and compression springs are respectively installed at the two ends of the valve core, an outer pipe is sleeved on the outer wall of the valve body, the lower end of the outer pipe is connected to the upper end of a side flow protection sleeve through a transition sleeve, a polygonal wire is arranged outside the support rib, a pressing cap is installed at the lower end of the side flow protection sleeve, and a high-temperature-resistant sealing gasket and a guide sleeve are installed at the lower part of the pressing cap. The beneficial effects are that the valve body, the valve core, the springs and the compression springs form throttling control of steam injection and liquid and water control production; the lower part of the side flow protection sleeve is freely telescopic and can be adjusted according to the temperature difference, and the combination of the side flow protection sleeve and the polygonal wire realizes long-term sand prevention, so that balanced steam injection, liquid and water control production and long-term sand blocking of the entire oil layer section can be realized through each screen pipe.

Description

Technical Field

[0001] This invention relates to the field of petroleum extraction technology, and in particular to a screen pipe for sand control and completion of heavy oil thermal recovery wells and its application method. Background Technology

[0002] Currently, heavy oil reservoirs are the main battleground for stabilizing and increasing oil production. Because most heavy oil reservoirs are shallow, have loosely cemented formations, and are prone to sand production, early sand control well completion is necessary. To extend the effectiveness of sand control wells, the current common sand control technology uses screen pipes + gravel packing to form a high-permeability gravel layer + screen pipe sand control layer. Simultaneously, due to the poor fluidity of heavy oil at formation temperatures, heavy oil wells often employ thermal recovery methods such as steam injection, well shut-in, and steam huff and puff for production. The specific process is as follows: (1) Steam injection stage: High-temperature and high-pressure steam at about 300°C is injected through the gasoline injection pipe, through the screen pipe and gravel layer into the oil layer, increasing the oil layer temperature and reducing the viscosity of crude oil; (2) Well shut-in stage: The injection is stopped and the well is shut in, allowing the high-temperature and high-pressure steam to diffuse to the deep part of the oil layer and increase the steam coverage area; (3) Production stage: Crude oil heated and reduced in viscosity by steam is produced from the oil layer and flows through the gravel layer and screen pipe into the wellbore; (4) Multiple rounds of steam injection and spitting: (1) to (3) above constitute one round of steam injection and spitting. When the thermal efficiency of this round decreases, the next round of steam injection and spitting is carried out. This multi-round steam injection and spitting and screen pipe + gravel filling early sand control completion method provides strong technical support for the effective exploitation of heavy oil reservoirs. However, in the process of application, the following problems still need to be solved: (1) The problem of balanced steam injection effect: Due to the high temperature and high pressure sealing at around 300℃, the layered balanced steam injection technology is not yet mature, and the number of steam injection valves for layered steam injection is limited. Under high temperature steam injection, it is difficult to intelligently adjust the steam injection in each layer of the well. If balanced control can be achieved in each screen pipe, the existing problem of uneven steam injection can be effectively solved, thereby improving the balanced steam effect of the oil layer.

[0003] (2) The problem of short service life of screen pipes: Existing screen pipes used in thermal recovery wells all adopt the conventional sand control screen pipe approach, which is not very targeted and has a short service life. For example, the patented "High-strength Steam Injection Thermal Recovery Screen Pipe" (ZL2011101389367) consists of couplings, centralizers, base pipes, welded rings, precision filter layers, spiral filter layers, and coarse filter layers. The precision filter layer, spiral filter layer, and coarse filter layer are installed sequentially from the inside to the outside on the base pipe. The two ends of the precision filter layer, spiral filter layer, and coarse filter layer are sealed and fixed to the base pipe by welded rings. First, the outer sand control layer is made of stainless steel and is welded and fixed to the base pipe at both ends. The base pipe is usually made of low carbon alloy steel such as N80. The thermal expansion rate of the outer sand control layer is different from that of the base pipe. During the steam injection and extraction of thermal recovery wells, due to the large temperature difference, the sand control layer is easily damaged by expansion and contraction and tension. Meanwhile, during multiple rounds of steam injection and production, the dense gravel filling layer outside the screen pipe will be broken up. This type of base pipe with holes and a sand-blocking layer on the outside allows the injected and produced hot fluid to directly erode the weak sand-blocking layer through the holes. As a result, the sand-blocking layer is easily damaged by the hot fluid carrying sand during implementation, leading to a short service life of the sand-blocking screen pipe.

[0004] (3) The problem of formation water coning and ridgeing in heavy oil extraction: Compared with the fluidity of heavy oil crude oil, formation water has better fluidity. Therefore, the problem of formation water coning and ridgeing in heavy oil extraction is particularly prominent, which leads to rapid water incoming of heavy oil thermal wells, serious water flooding of oil reservoirs, and reduced production capacity of thermal wells, or even abandonment. Summary of the Invention

[0005] The purpose of this invention is to address the aforementioned deficiencies in existing technologies by providing a screen pipe for sand control completion in heavy oil thermal recovery wells and its usage method. On one hand, it allows injected steam to pass through the valve core, and then through the sand control layer formed by the support ribs, polygonal wire, and sideflow protective sleeve, to be evenly delivered to the oil layer, reducing damage to the sand control layer and extending its service life. On the other hand, the valve body, valve core, spring, and compression spring form a throttling control for steam injection and liquid / water production. Furthermore, the upper end of the sideflow protective sleeve is welded and fixed to the lower joint of the transition sleeve, while the lower part freely expands and contracts with temperature differences. During large temperature differences in steam injection and discharge, this prevents tearing and damage to the sand control layer formed by the sideflow protective sleeve, polygonal wire, and support ribs, further extending its service life.

[0006] This invention relates to a screen pipe for sand control and completion in heavy oil thermal recovery wells. The technical solution includes a base pipe, a coupling, a lifting sub, a valve body, an outer pipe, a valve core, a spring, a compression spring, a sideflow protection sleeve, polygonal wire, support ribs, a pressure cap, a high-temperature resistant sealing gasket, a guide sleeve, and a transition sleeve. The upper end of the base pipe is connected to the lower end of the valve body, and the upper end of the valve body is connected to the coupling via the lifting sub. The valve body has a valve core mounting groove in its middle, in which the valve core is installed. A spring is installed at the outer end of the valve core, and a compression spring is installed at the inner end of the valve core. An outer pipe is fitted over the outer wall of the valve body, and the lower end of the outer pipe is connected to the upper end of the sideflow protection sleeve via a transition sleeve. Support ribs are fitted over the outside of the base pipe, and polygonal wire is installed outside the support ribs. A polygonal wire is wound around a side-flow protective sleeve, on which multiple side-flow holes are evenly distributed. A pressure cap is installed at the lower end of the side-flow protective sleeve, and a high-temperature resistant sealing gasket is installed below the pressure cap. A guide sleeve is installed below the high-temperature resistant sealing gasket. The pressure cap, high-temperature resistant sealing gasket, and guide sleeve form a dynamically adjustable sealing system that adapts to temperature differences between the outer tube, transition sleeve, and side-flow protective sleeve. When steam is injected, the valve core moves outward to compress the spring, achieving a balanced flow of steam into the annulus between the valve body and the outer tube. After being evenly distributed by the support ribs, the polygonal wire, and the side-flow protective sleeve, the steam enters the formation. During production, the produced water pushes the valve core inward to reduce the flow channel, thereby controlling the amount of liquid flowing into the screen tube.

[0007] Preferably, the valve core includes a valve core body, a valve core control head, a spring sleeve, a spring mounting post, a spring mounting groove, and a compression spring mounting groove. The spring mounting groove is installed on the upper side of the valve core body, the spring mounting post is installed at the center of the spring mounting groove, and the spring sleeve is installed on the outer side. The spring is installed on the spring mounting groove and the spring mounting post. A compression spring mounting groove is provided at the center of the lower side of the valve core body for installing a compression spring. A downwardly extending valve core control head is fixed at the center of the compression spring mounting groove. The valve core control head has a frustum-shaped conical structure and is used to connect with the central liquid passage hole of the valve core mounting groove.

[0008] Preferably, the valve core mounting groove has a central liquid passage hole at its center, and a valve core support platform is provided on the upper step of the central liquid passage hole, with multiple support columns distributed on the surface of the valve core support platform.

[0009] Preferably, multiple support columns are distributed in a spiral structure on the upper surface of the valve core support platform.

[0010] Preferably, multiple support columns are distributed on the upper surface of the valve core support platform and are provided with multiple liquid passage notches. When the valve core body is pressed down on the valve core support platform, the liquid passage is formed by the support of the valve core support platform. The liquid flows along the cavity between the support columns and the liquid passage notches to the central liquid passage hole and then enters the screen tube.

[0011] Preferably, multiple support columns are spirally distributed on the upper surface of the valve core support platform, and multiple liquid passage gaps are provided in the middle of the spirally distributed support columns. When the valve core body is pressed down on the valve core support platform, the spirally distributed valve core support platform supports the flow of liquid through the channel, which flows into the central liquid passage hole along the cavity between the support columns and the liquid passage gaps, and then enters the screen tube.

[0012] Preferably, the aforementioned transition sleeve includes a transition sleeve body, an upper transition sleeve connector, and a lower transition sleeve connector. The transition sleeve body has a circular ring structure. The upper transition sleeve connector is provided at the upper end of the transition sleeve body and has an external thread, which connects to the lower inner wall of the outer tube through the external thread. The lower transition sleeve connector is provided at the lower end of the transition sleeve body for connecting to the upper end of the side flow protection sleeve, the polygonal winding wire, and the support rib. The upper end of the side flow protection sleeve is welded and fixed to the lower transition sleeve connector.

[0013] Preferably, the lower end of the side flow protection sleeve is welded and fixed to the pressure cap. The lower end of the pressure cap is provided with an internal thread and is threaded to the upper end of the guide sleeve through the internal thread. A high-temperature resistant sealing gasket is installed in the cavity between the lower end of the pressure cap and the upper end of the guide sleeve.

[0014] The method for using the screen pipe for sand control completion in heavy oil thermal recovery wells mentioned in this invention includes the following steps: 1. When injecting steam evenly: Steam is injected into the tubing at the surface wellhead. The steam travels along the coupling and lift section to the valve body. Because the injected steam pressure is greater than the spring force, the valve core moves outward and compresses the spring. The steam enters the annulus between the valve body and the outer tubing through the central liquid passage. It is then evenly distributed through the support ribs, polygonal wire, and side flow protection sleeve before being delivered into the formation. This ensures that the steam is injected evenly into the formation, improving the steam uniformity effect of the oil layer. In addition, the upper end of the side flow protection sleeve is welded and fixed to the lower joint of the transition sleeve. The lower part can freely expand and contract with temperature differences. During the large temperature difference process of steam injection and discharge, the sand-proof layer formed by the side flow protection sleeve, polygonal wire, and support ribs is prevented from tearing and being damaged. II. During controlled liquid and water extraction oil production: After steam injection is completed and the well is shut down for a period of time, oil production begins. The produced water from the oil layer enters the annulus between the valve body and the outer pipe along the side flow protective sleeve and the polygonal winding wire. When the sum of the pressure of the produced water and the elastic force of the spring is greater than the elastic force of the compression spring, the valve core moves inward. The lower surface of the valve core body contacts the support column on the surface of the valve core support platform, forming a flow-limiting passage, thereby controlling the amount of produced water flowing into the screen tube.

[0015] The method for using screen pipes for sand control completion in heavy oil thermal recovery wells mentioned in this invention also has a long-term sand control function: Steam is injected through the upper valve core and flows sideways through the sand-proof layer formed by the side-flow protective sleeve, polygonal wire, and support ribs, preventing steam from directly eroding the sand-proof layer and extending its lifespan. Furthermore, under the protection of the side-flow protective sleeve, the polygonal wire forms a dual-stage self-cleaning and erosion-resistant structure, further increasing the erosion resistance of the sand-proof layer.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The base pipe of this invention uses a complete cylindrical pipe, which, together with the valve body and valve core, allows the injected steam to pass smoothly through the valve core and then be evenly delivered to the oil layer through the sand-proof layer formed by the support ribs, polygonal wires, and side flow protective sleeve. This also reduces damage to the sand-proof layer and extends its service life. On the other hand, during water-controlled oil production, the valve core control head and support column located on the lower side of the valve core body form a flow-limiting passage. The valve body, valve core, spring, and compression spring then form a throttling control for steam injection and liquid and water production. Furthermore, the upper end of the side flow protective sleeve is welded and fixed to the lower joint of the transition sleeve, and the lower part can freely expand and contract with temperature differences. During the large temperature difference process of steam injection and discharge, the sand-proof layer formed by the side flow protective sleeve, polygonal wires, and support ribs is prevented from tearing and being damaged. In addition, through the combination of the side flow protective sleeve and polygonal wires, even steam injection, liquid and water control, and long-term sand blocking can be achieved throughout the entire oil layer section through each screen pipe. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 yes Figure 1 Enlarged diagram of part A in the diagram; Figure 3 yes Figure 1 Enlarged schematic diagram of part B in the diagram; Figure 4 This is an enlarged schematic diagram of the valve core mounting groove in the valve body; Figure 5 This is an enlarged schematic diagram of the valve core without the spring and compression spring installed; Figure 6 This is a schematic diagram of the valve core support platform from a top view of the large helical pitch. Figure 7 This is a schematic diagram of the valve core support platform from a top view of the small helical pitch. Figure 8 This is a schematic diagram of the transition sleeve structure; Figure 9 This is an enlarged schematic diagram of the pressure cap and guide sleeve. Figure 10 This is an overall schematic diagram of the steam injection process; Figure 11 This is a schematic diagram of the valve core part when steam is injected; Figure 12 This is an overall schematic diagram of oil production and sand control. Figure 13 This is a schematic diagram of the valve core part used in oil production and sand control. In the diagram: 1. Coupling; 2. Lifting section; 3. Valve body; 4. Outer pipe; 5. Valve core; 6. Spring; 7. Compression spring; 8. Base pipe; 9. Side flow protection sleeve; 10. Polygonal wire winding; 11. Support rib; 12. Pressure cap; 13. High temperature resistant sealing gasket; 14. Guide sleeve; 15. Transition sleeve. 3.1 Valve core mounting groove, 3.2 Central liquid passage hole, 3.3 Valve core support platform, 3.4 Support column, 3.5 Liquid passage notch, 5.1 Valve core body, 5.2 Valve core control head, 5.3 Spring outer sleeve, 5.4 Spring mounting column, 5.5 Spring mounting groove, 5.6 Compression spring mounting groove, 9.1 Side flow hole, 10.1 First included angle, 10.2 Second included angle, 15.1 Transition sleeve body, 15.2 Upper connector of transition sleeve, 15.3 Lower connector of transition sleeve. Detailed Implementation

[0018] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0019] Example 1, referring to Figures 1-12This invention relates to a screen pipe for sand control and completion in heavy oil thermal recovery wells, comprising a coupling 1, a lifting sub 2, a valve body 3, an outer pipe 4, a valve core 5, a spring 6, a compression spring 7, a base pipe 8, a sideflow protection sleeve 9, a polygonal wire coil 10, a support rib 11, a pressure cap 12, a high-temperature resistant sealing gasket 13, a guide sleeve 14, and a transition sleeve 15. The upper end of the base pipe 8 is connected to the lower end of the valve body 3, and the upper end of the valve body 3 is connected to the coupling 1 via the lifting sub 2. The valve body 3 has a valve core mounting groove 3.1 in the middle, in which the valve core 5 is installed. A spring 6 is installed on the outer end of the valve core 5, and a compression spring 7 is installed on the inner end of the valve core 5. The outer pipe 4 is sleeved on the outer wall of the valve body 3, and the lower end of the outer pipe 4 is connected to the upper end of the sideflow protection sleeve 9 via the transition sleeve 15. A support rib 11 is sleeved on the outside of the base pipe 8, and a polygonal wire coil is installed on the outside of the support rib 11. A polygonal wire 10 is wound around a side flow protective sleeve 9. Multiple side flow holes 9.1 are evenly distributed on the side flow protective sleeve 9. A pressure cap 12 is installed at the lower end of the side flow protective sleeve 9. A high-temperature resistant sealing gasket 13 is installed below the pressure cap 12. A guide sleeve 14 is installed below the high-temperature resistant sealing gasket 13. The pressure cap 12, the high-temperature resistant sealing gasket 13, and the guide sleeve 14 form a dynamically adjustable sealing system that adapts to temperature differences, connecting the outer tube 4, the transition sleeve 15, and the side flow protective sleeve 9. When steam is injected, the valve core 5 moves outward to compress the spring 6, achieving a balanced flow of steam into the annulus between the valve body 3 and the outer tube 4. After passing through the support rib 11, the polygonal wire 10, and the side flow protective sleeve 9, the steam enters the formation. During production, the produced water pushes the valve core 5 inward, reducing the flow channel and controlling the amount of liquid flowing into the screen tube.

[0020] Reference Figure 5 The valve core 5 mentioned in this invention includes a valve core body 5.1, a valve core control head 5.2, a spring sleeve 5.3, a spring mounting post 5.4, a spring mounting groove 5.5, and a compression spring mounting groove 5.6. The spring mounting groove 5.5 is installed on the upper side of the valve core body 5.1, the spring mounting post 5.4 is installed at the center of the spring mounting groove 5.5, and the spring sleeve 5.3 is installed on the outer side. The spring 6 is installed on the spring mounting groove 5.5 and the spring mounting post 5.4. A compression spring mounting groove 5.6 is provided at the lower center of the valve core body 5.1 for installing a compression spring 7. The valve core control head 5.2, which extends downward, is fixed at the center of the compression spring mounting groove 5.6. The valve core control head 5.2 has a frustum conical structure and is used to connect with the liquid passage hole 3.2 at the center of the valve core mounting groove 3.1.

[0021] Reference Figure 4 The valve core mounting groove 3.1 mentioned in this invention has a central liquid passage hole 3.2 at its center, and a valve core support platform 3.3 is provided on the upper step of the central liquid passage hole 3.2. Multiple support columns 3.4 are distributed on the surface of the valve core support platform 3.3.

[0022] Reference Figure 7The multiple support columns 34 mentioned in this invention are spirally distributed on the upper surface of the valve core support platform 33, and multiple liquid passage gaps 35 are provided in the middle of the spirally distributed support columns 34 with small pitch. When the valve core body 51 is pressed down on the valve core support platform 33, the liquid passage is formed by the support of the spirally distributed valve core support platform 33. The liquid flows along the cavity between the support columns 34 and the liquid passage gaps 35 to the central liquid passage hole 32, and then enters the screen tube.

[0023] Reference Figure 8 The transition sleeve 15 mentioned in this invention includes a transition sleeve body 15.1, an upper transition sleeve connector 15.2, and a lower transition sleeve connector 15.3. The transition sleeve body 15.1 has a circular structure. The upper transition sleeve connector 15.2 is provided at the upper end of the transition sleeve body 15.1 and has an external thread, which is connected to the lower inner wall of the outer tube 4 through the external thread. The lower transition sleeve connector 15.3 is provided at the lower end of the transition sleeve body 15.1 for connecting with the upper end of the side flow protection sleeve 9, the polygonal winding wire 10, and the support rib 11. The upper end of the side flow protection sleeve 9 is welded and fixed to the lower transition sleeve connector 15.3.

[0024] Reference Figure 9 The lower end of the side flow protection sleeve 9 mentioned in this invention is welded and fixed to the pressure cap 12. The lower end of the pressure cap 12 is provided with an internal thread and is threaded to the upper end of the guide sleeve 14 through the internal thread. A high temperature resistant sealing gasket 13 is installed in the cavity between the lower end of the pressure cap 12 and the upper end of the guide sleeve 14.

[0025] Additionally, refer to Figure 3 The polygonal wire 10 is wound around the support rib 11, forming a first included angle 10.1 and a second included angle 10.2, forming a two-level self-cleaning and erosion-resistant structure, which further increases the erosion resistance of the wire-wound sand-proof layer.

[0026] Reference Figures 10-13 The method of using the screen pipe for sand control completion in heavy oil thermal recovery wells mentioned in this invention includes the following steps: 1. When injecting steam evenly: Steam is injected into the tubing at the wellhead. The steam travels along the coupling 1 and the lifting sub 2 to the valve body 3. Because the injected steam pressure is greater than the spring force of the spring 6, the valve core 5 moves outward to compress the spring 6. The steam enters the annulus between the valve body 3 and the outer tube 4 through the central liquid passage 3.2, and then flows evenly through the support rib 11, the polygonal wire 10 and the side flow protection sleeve 9 before being sent into the formation. This ensures that the steam is injected evenly into the formation, improving the steam uniformity effect of the oil layer. In addition, the upper end of the side flow protection sleeve 9 is welded and fixed to the lower joint 15.3 of the transition sleeve, and the lower part can freely expand and contract with the temperature difference. During the large temperature difference process of steam injection and discharge, the sand-proof layer formed by the side flow protection sleeve 9, the polygonal wire 10 and the support rib 11 is prevented from tearing and being damaged. II. During controlled liquid and water extraction oil production: After steam injection is completed and the well is shut down for a period of time, oil production begins. When the water production in the oil layer is large, the water flow velocity is high. The water enters the annulus between the valve body 3 and the outer pipe 4 along the side flow protective sleeve 9 and the polygonal winding wire 10. When the sum of the pressure of the water production and the elastic force of the spring 6 is greater than the elastic force of the compression spring 7, the valve core 5 moves inward. The lower surface of the valve core body 5.1 contacts the support column 3.4 on the surface of the valve core support platform 3.3, forming a flow-limiting passage to control the amount of water produced flowing into the screen tube.

[0027] In addition, the present invention also has a long-lasting sand-proof function: Steam is injected through the upper valve core 5 and flows sideways through the sand-proof layer formed by the side-flow protective sleeve 9, the polygonal wire 10, and the support rib 11, preventing steam from directly eroding the sand-proof layer and extending its lifespan. Furthermore, under the protection of the side-flow protective sleeve 9, the polygonal wire 10 forms a dual-stage self-cleaning and erosion-resistant structure, further increasing the erosion resistance of the sand-proof layer.

[0028] Example 2: A screen pipe for sand control and completion of heavy oil thermal recovery wells mentioned in this invention includes a coupling 1, a lifting sub 2, a valve body 3, an outer pipe 4, a valve core 5, a spring 6, a compression spring 7, a base pipe 8, a sideflow protection sleeve 9, a polygonal wire coil 10, a support rib 11, a pressure cap 12, a high-temperature resistant sealing gasket 13, a guide sleeve 14, and a transition sleeve 15. The upper end of the base pipe 8 is connected to the lower end of the valve body 3. The upper end of the valve body 3 is connected to the coupling 1 through the lifting sub 2. The valve body 3 has a valve core mounting groove 3.1 in the middle, and the valve core 5 is installed in the valve core mounting groove 3.1. A spring 6 is installed on the outer end of the valve core 5, and a compression spring 7 is installed on the inner end of the valve core 5. The outer pipe 4 is sleeved on the outer wall of the valve body 3. The lower end of the outer pipe 4 is connected to the upper end of the sideflow protection sleeve 9 through the transition sleeve 15. A support rib 11 is sleeved on the outside of the base pipe 8, and multiple wire coils are installed on the outside of the support rib 11. A polygonal wire 10 is used, and a side flow protection sleeve 9 is installed outside the polygonal wire 10. Multiple side flow holes 9.1 are evenly distributed on the side flow protection sleeve 9. A pressure cap 12 is installed at the lower end of the side flow protection sleeve 9, a high-temperature resistant sealing gasket 13 is installed at the lower part of the pressure cap 12, and a guide sleeve 14 is installed below the high-temperature resistant sealing gasket 13. The pressure cap 12, the high-temperature resistant sealing gasket 13, and the guide sleeve 14 form a follow-up regulating sealing system that changes with temperature difference, so that the outer tube 4, the transition sleeve 15, and the side flow protection sleeve 9 can be formed. When steam is injected, the valve core 5 moves outward to compress the spring 6, so that the steam flows evenly into the annulus between the valve body 3 and the outer tube 4. After passing through the support rib 11, the polygonal wire 10, and the side flow protection sleeve 9 for even distribution, the steam enters the formation. During production, the produced water pushes the valve core 5 inward to reduce the flow channel and control the amount of liquid flowing into the screen tube.

[0029] The difference from Example 1 is: The multiple support columns 3.4 mentioned in this embodiment are distributed on the upper surface of the valve core support platform 3.3 and are provided with multiple liquid passage gaps 3.5. When the valve core body 5.1 is pressed down on the valve core support platform 3.3, the liquid passage is formed by the support of the valve core support platform 3.3. The liquid flows along the cavity between the support columns 3.4 and the liquid passage gaps 3.5 to the central liquid passage hole 3.2 and then enters the screen tube.

[0030] Example 3: A screen pipe for sand control and completion in heavy oil thermal recovery wells mentioned in this invention includes a coupling 1, a lifting sub 2, a valve body 3, an outer pipe 4, a valve core 5, a spring 6, a compression spring 7, a base pipe 8, a sideflow protection sleeve 9, a polygonal wire coil 10, a support rib 11, a pressure cap 12, a high-temperature resistant sealing gasket 13, a guide sleeve 14, and a transition sleeve 15. The upper end of the base pipe 8 is connected to the lower end of the valve body 3. The upper end of the valve body 3 is connected to the coupling 1 through the lifting sub 2. The valve body 3 has a valve core mounting groove 3.1 in the middle, and the valve core 5 is installed in the valve core mounting groove 3.1. A spring 6 is installed on the outer end of the valve core 5, and a compression spring 7 is installed on the inner end of the valve core 5. The outer pipe 4 is sleeved on the outer wall of the valve body 3. The lower end of the outer pipe 4 is connected to the upper end of the sideflow protection sleeve 9 through the transition sleeve 15. A support rib 11 is sleeved on the outside of the base pipe 8, and multiple wire coils are installed on the outside of the support rib 11. A polygonal wire 10 is used, and a side flow protection sleeve 9 is installed outside the polygonal wire 10. Multiple side flow holes 9.1 are evenly distributed on the side flow protection sleeve 9. A pressure cap 12 is installed at the lower end of the side flow protection sleeve 9, a high-temperature resistant sealing gasket 13 is installed at the lower part of the pressure cap 12, and a guide sleeve 14 is installed below the high-temperature resistant sealing gasket 13. The pressure cap 12, the high-temperature resistant sealing gasket 13, and the guide sleeve 14 form a follow-up regulating sealing system that changes with temperature difference, so that the outer tube 4, the transition sleeve 15, and the side flow protection sleeve 9 can be formed. When steam is injected, the valve core 5 moves outward to compress the spring 6, so that the steam flows evenly into the annulus between the valve body 3 and the outer tube 4. After passing through the support rib 11, the polygonal wire 10, and the side flow protection sleeve 9 for even distribution, the steam enters the formation. During production, the produced water pushes the valve core 5 inward to reduce the flow channel and control the amount of liquid flowing into the screen tube.

[0031] The difference from Example 1 is: Reference Figure 6 Multiple support columns 3.4 are distributed on the upper surface of the valve core support platform 3.3 in a spiral structure with a large pitch.

[0032] During oil production, when the water production in the oil layer is large, the high flow velocity of the produced water causes two main effects: first, the valve core 5 moves inward, reducing the flow passage between the valve core 5 and the valve body 3; second, multiple support columns 3.4 are distributed in a spiral structure on the upper surface of the valve core support platform 3.3, and under the action of high speed and swirling water, they adsorb the valve core 5, and cooperate with the compression spring 7 and the spring 6 to control the amount of liquid flowing into the screen tube.

[0033] The above description is merely a partial preferred embodiment of the present invention. Any person skilled in the art can modify the above-described technical solutions or modify them into equivalent technical solutions. Therefore, any simple modifications or equivalent transformations made based on the technical solutions of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A screen pipe for sand control and completion in heavy oil thermal recovery wells, comprising a base pipe (8), characterized in that: It also includes a coupling (1), a lifting section (2), a valve body (3), an outer tube (4), a valve core (5), a spring (6), a compression spring (7), a side flow protection sleeve (9), a polygonal wire (10), a support rib (11), a pressure cap (12), a high-temperature resistant sealing gasket (13), a guide sleeve (14), and a transition sleeve (15). The upper end of the base tube (8) is connected to the lower end of the valve body (3), and the upper end of the valve body (3) is connected to the coupling (1) through the lifting section (2). (3) has a valve core mounting groove (3.1) in the middle, and a valve core (5) is installed in the valve core mounting groove (3.1). A spring (6) is installed on the outer end of the valve core (5), and a compression spring (7) is installed on the inner end of the valve core (5). An outer tube (4) is sleeved on the outer wall of the valve body (3). The lower end of the outer tube (4) is connected to the upper end of the side flow protection sleeve (9) through a transition sleeve (15). A support rib (11) is sleeved on the outside of the base tube (8). A polygonal wire is installed on the outside of the support rib (11). 10), a side flow protection sleeve (9) is installed outside the polygonal wire (10). Multiple side flow holes (9.1) are evenly distributed on the side flow protection sleeve (9). A pressure cap (12) is installed at the lower end of the side flow protection sleeve (9). A high temperature resistant sealing gasket (13) is installed at the lower part of the pressure cap (12). A guide sleeve (14) is installed below the high temperature resistant sealing gasket (13). The outer tube (4), transition sleeve (15) and The side flow protection sleeve (9) forms a follow-up adjustment sealing system that changes with temperature difference; when steam is injected, the valve core (5) moves outward to squeeze the spring (6), so that the steam flows evenly into the annulus between the valve body (3) and the outer tube (4), and then enters the formation after being evenly distributed by the support rib (11), the polygonal winding wire (10) and the side flow protection sleeve (9); during production, the produced water pushes the valve core (5) to move inward to reduce the flow channel and realize the control of the amount of liquid flowing into the screen tube.

2. The screen pipe for sand control and completion of heavy oil thermal recovery wells according to claim 1, characterized in that: The valve core (5) includes a valve core body (5.1), a valve core control head (5.2), a spring sleeve (5.3), a spring mounting post (5.4), a spring mounting groove (5.5), and a compression spring mounting groove (5.6). The spring mounting groove (5.5) is installed on the upper side of the valve core body (5.1), the spring mounting post (5.4) is installed at the center of the spring mounting groove (5.5), and the spring sleeve (5.3) is installed on the outer side. The spring (6) is installed on the spring mounting groove (5.5) and the spring mounting post (5.4). A compression spring mounting groove (5.6) is provided at the center of the lower side of the valve core body (5.1) for installing a compression spring (7). A downwardly extending valve core control head (5.2) is fixed at the center of the compression spring mounting groove (5.6). The valve core control head (5.2) is a frustum conical structure for connecting with the central liquid passage hole (3.2) of the valve core mounting groove (3.1).

3. The screen pipe for sand control and completion of heavy oil thermal recovery wells according to claim 2, characterized in that: The valve core mounting groove (3.1) has a central liquid passage hole (3.2) at its center, and a valve core support platform (3.3) is provided on the upper step of the central liquid passage hole (3.2). Multiple support columns (3.4) are distributed on the surface of the valve core support platform (3.3).

4. The screen pipe for sand control and completion of heavy oil thermal recovery wells according to claim 3, characterized in that: Multiple support columns (3.4) are distributed in a spiral structure on the upper surface of the valve core support platform (3.3).

5. The screen pipe for sand control and completion of heavy oil thermal recovery wells according to claim 3, characterized in that: Multiple support columns (3.4) are distributed on the upper surface of the valve core support platform (3.3) and multiple liquid passage gaps (3.5) are provided. When the valve core body (5.1) is pressed down on the valve core support platform (3.3), the liquid passage is formed by the support of the valve core support platform (3.3). The liquid flows along the cavity between the support columns (3.4) and the liquid passage gaps (3.5) into the central liquid passage hole (3.2) and then into the screen tube.

6. The screen pipe for sand control and completion of heavy oil thermal recovery wells according to claim 5, characterized in that: Multiple support columns (3.4) are spirally distributed on the upper surface of the valve core support platform (3.3), and multiple liquid passage gaps (3.5) are provided in the middle of the spirally distributed support columns (3.4). When the valve core body (5.1) is pressed down on the valve core support platform (3.3), the liquid passage is formed by the support of the spirally distributed valve core support platform (3.3). The liquid flows along the cavity between the support columns (3.4) and the liquid passage gaps (3.5) into the central liquid passage hole (3.2) and then into the screen tube.

7. The screen pipe for sand control and completion of heavy oil thermal recovery wells according to claim 6, characterized in that: The transition sleeve (15) includes a transition sleeve body (15.1), an upper transition sleeve connector (15.2), and a lower transition sleeve connector (15.3). The transition sleeve body (15.1) is a circular ring structure. The upper transition sleeve connector (15.2) is provided at the upper end of the transition sleeve body (15.1) and is provided with an external thread, which is connected to the lower inner wall of the outer tube (4) through the external thread. The lower end of the transition sleeve body (15.1) is provided with a lower transition sleeve connector (15.3), which is used to connect with the upper end of the side flow protection sleeve (9), the polygonal winding wire (10), and the support rib (11). The upper end of the side flow protection sleeve (9) is welded and fixed to the lower transition sleeve connector (15.3).

8. The screen pipe for sand control and completion of heavy oil thermal recovery wells according to claim 7, characterized in that: The lower end of the side flow protection sleeve (9) is welded and fixed to the pressure cap (12). The lower end of the pressure cap (12) is provided with an internal thread and is threaded to the upper end of the guide sleeve (14) through the internal thread. A high temperature resistant sealing gasket (13) is installed in the cavity between the lower end of the pressure cap (12) and the upper end of the guide sleeve (14).

9. A method of using a screen pipe for sand control and completion in heavy oil thermal recovery wells as described in claim 8, characterized in that: Includes the following processes:

1. When injecting steam evenly: Steam is injected into the tubing at the wellhead. The steam travels along the coupling (1) and lifting sub (2) to the valve body (3). Since the injected steam pressure is greater than the spring force of the spring (6), the valve core (5) moves outward to squeeze the spring (6). The steam enters the annulus between the valve body (3) and the outer tube (4) through the central liquid passage (3.2). After being evenly distributed through the support rib (11), polygonal wire (10) and side flow protection sleeve (9), the steam is sent into the formation, so that the steam is evenly injected into the formation and the steam balance effect of the oil layer is improved. In addition, the upper end of the side flow protection sleeve (9) is welded and fixed to the lower joint (15.3) of the transition sleeve. The lower part can freely expand and contract with the temperature difference. During the large temperature difference process of steam injection and discharge, the sand-proof layer formed by the side flow protection sleeve (9), polygonal wire (10) and support rib (11) is prevented from tearing and being damaged. II. During controlled liquid and water extraction oil production: After steam injection is completed and the well is shut down for a period of time, oil production begins. The produced water from the oil layer enters the annulus between the valve body (3) and the outer pipe (4) along the side flow protective sleeve (9) and the polygonal winding wire (10). When the sum of the pressure of the produced water and the elastic force of the spring (6) is greater than the elastic force of the compression spring (7), the valve core (5) moves inward. The lower surface of the valve core body (5.1) contacts the support column (3.4) on the surface of the valve core support platform (3.3), forming a flow-limiting passage to control the amount of produced water flowing into the screen pipe.

10. The method of using the screen pipe for sand control and completion in heavy oil thermal recovery wells according to claim 9, characterized in that: It also has a long-lasting sand-proof function: Steam is injected through the upper valve core (5), and the side flow passes through the sand-proof layer formed by the side flow protection sleeve (9), polygonal wire (10) and support rib (11), which prevents steam from directly eroding the sand-proof layer and extends the life of the sand-proof layer. Under the protection of the side flow protection sleeve (9), the polygonal wire (10) forms a dual-stage self-cleaning and erosion-resistant structure, further increasing the erosion resistance of the sand-proof layer.

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