An integrated screen pipe for fracturing and acidizing oil production

Abstract

This utility model discloses an integrated screen pipe for fracturing and acidizing oil production, including a central pipe and an outer sleeve. A Tesla valve groove is provided on the portion of the central pipe's outer wall covered by the outer sleeve. The Tesla valve groove includes a main flow channel and a branch channel located on the side of the main flow channel. The main flow channel is spiral-shaped. The central pipe has a forward flow hole communicating with the main flow channel, and the outer sleeve has a reverse flow hole communicating with the main flow channel. The branch channel ensures that the direction from the forward flow hole to the reverse flow hole is the forward flow direction. The spiral-shaped Tesla valve groove on the cylindrical surface of the central pipe of this utility model achieves unidirectional flow restriction, enabling rapid forward injection and flow restriction or even shut-off during reverse injection. This effectively avoids the risks of overflow and blowout caused by sudden increases in fracturing, and can limit and stabilize flow during oil and gas production, ensuring the safe extraction of oil reservoirs.

Description

Technical Field

[0001] This utility model relates to the field of petroleum development technology, specifically to an integrated screen pipe for fracturing and acidizing oil production. Background Technology

[0002] The well completion methods used in oil and gas field development include: perforation completion, open hole completion, liner completion, and gravel packing completion. Among these, perforation completion is the most widely used. In perforation completion, the oil layer casing is first run into the well, cemented, and then perforated into the production layer. After removing the oil layer tools, a sand control screen is run downhole for sand control. However, with the continuous development of oil fields, existing sand control screens, especially in multi-layer sand control or horizontal well sections, cannot control the flow of produced fluid in layers or sections, failing to achieve layered or segmented production. This leads to an increase in the water content of the produced fluid after a period of production following sand control, affecting the normal production of other oil layers.

[0003] Loose sandstone oil and gas reservoirs often face the problem of sand production at the bottom of the well during the development process. For older wells that have been in operation for a period of time, severe formation sand production can lead to screen blockage or failure, affecting production and even causing the well to be abandoned. In this case, secondary fracturing and production enhancement operations need to be carried out in the older well.

[0004] In related technologies, fracturing using screened tubing is commonly employed, followed by chemical or mechanical sand control after damage to the old screened tubing. This approach is prone to problems such as short sand control lifespan and small wellbore diameter, significantly impacting well quality and becoming a major obstacle to increased production in loose sandstone oil and gas reservoirs. Currently, some solutions utilize pre-fabricated fracturing sleeves in the completion string. While this avoids screened tubing fracturing, conventional tubing cannot effectively isolate different producing layers during fracturing, resulting in low efficiency and affecting fracturing effectiveness; therefore, improvements are needed.

[0005] Announcement No. CN221682952U discloses a Tesla water control screen tube. The front end of the screen tube's main body base tube is provided with an external connector, and the rear end is equipped with a filter unit. A guide tube is installed on one side of the filter unit, and a Tesla valve is installed on the right side of the guide tube. A coupling is installed on the right side connector of the Tesla valve. The right side of the inner connecting tube of the Tesla valve is provided with a Tesla valve body. The surface of the Tesla valve body is provided with one or more water control grooves and one or more liquid inlet holes. An external guide sleeve is installed on the outside of the Tesla valve body, and the external guide sleeve and the right side connection body of the Tesla valve body are connected.

[0006] Publication No. CN116181282A discloses an intelligent well completion inflow control device and method based on a Tesla valve. The device includes an outer screen pipe, with tubing located inside the screen pipe. A one-way valve with a distribution plate is installed at one end of the screen pipe, and a Tesla valve flow channel is installed at the outlet of the one-way valve. The outlet of the Tesla valve is located inside the tubing. When reservoir fluid flows to the Tesla valve, its reverse flow-limiting characteristic is utilized. Due to the dominant inertial force of water and its high flow velocity, the Tesla valve flow channel structure restricts the inflow. Meanwhile, the viscous force of oil plays a dominant role, causing most of the oil to flow into the Tesla valve, thereby achieving water control.

[0007] The two existing technologies mentioned above use annular fluid flow, and the flow area is limited by the wellbore size. This patent increases the flow area by increasing the number of forward and reverse flow holes, and the flow area is not limited.

[0008] Publication No.: CN118088125A discloses a control device suitable for segmented water control and gas production in gas wells, including: a water control and gas production control device, comprising a support base pipe, a fixed installation groove, a Tesla valve type water controller, a gas flow and drag reduction groove, and a support base pipe outlet.

[0009] The aforementioned prior art uses modular Tesla valve units, and its spiral arrangement cannot change the number of modules on a device, which is fundamentally different from the spiral shape of the mainstream channel in this patent.

[0010] In summary, the technical solutions, technical problems to be solved, and beneficial effects of the above-disclosed technologies are all different from those of this utility model. For more technical features, technical problems to be solved, and beneficial effects of this utility model, the above-disclosed technical documents do not provide any technical inspiration. Utility Model Content

[0011] In order to overcome the shortcomings of the existing technology and solve at least one of the technical problems mentioned in the background art, this utility model provides an integrated screen pipe for fracturing and acidizing oil production.

[0012] To achieve the above objectives, the present invention adopts the following technical solution:

[0013] An integrated fracturing and acidizing oil recovery screen includes a central tube, an outer sleeve covering the central tube, and a Tesla valve groove on the portion of the central tube's outer wall covered by the outer sleeve. The Tesla valve groove includes a main flow channel and a branch channel located on the side of the main flow channel. The main flow channel is spiral-shaped. The central tube has a forward flow hole communicating with the main flow channel, and the outer sleeve has a reverse flow hole communicating with the main flow channel. The branch channel makes the direction from the forward flow hole to the reverse flow hole the forward flow direction.

[0014] Furthermore, the Tesla valve recess includes at least one main channel;

[0015] Specifically, one circumference of the main flow channel is connected to at least one forward flow hole and at least one reverse flow hole; the main flow channel has at least one branch channel between the forward flow hole and the adjacent reverse flow hole;

[0016] Specifically, the forward flow holes and reverse flow holes are arranged at intervals, and all forward flow holes and reverse flow holes are evenly distributed in the circumferential direction of the main flow channel.

[0017] Furthermore, the forward flow holes and reverse flow holes are arranged in separate rows, with the number of rows being the same as the number of holes on one circumference of the main flow channel.

[0018] Furthermore, the diversion channel includes a p-type groove, a q-type groove, a b-type groove, and a d-type groove, and the vertical parts of the p-type groove, q-type groove, b-type groove, and d-type groove all coincide with the main channel;

[0019] Specifically, the branch channel located above the main channel and facing downwards in the downstream direction is a p-shaped channel;

[0020] Specifically, the branch channel located below the main channel and facing downwards in the downstream direction is a Q-shaped channel;

[0021] Specifically, the branch channel located above the main channel and facing upwards in the downstream direction is a type B channel;

[0022] Specifically, the branch channel located below the main channel and facing upwards in the downstream direction is a d-shaped channel.

[0023] Furthermore, the main channel is provided with one or both of the following: a p-shaped groove and a q-shaped groove between the forward flow hole and the adjacent upper reverse flow hole;

[0024] Specifically, the main channel is provided with one or both of the following: a type b groove and a type d groove between the forward flow hole and the adjacent lower reverse flow hole.

[0025] Furthermore, the number of forward flow holes and reverse flow holes is the same.

[0026] Furthermore, the forward or reverse flow hole is located at the upper and lower ends of the main flow channel.

[0027] Furthermore, the outer wall of the central tube is provided with a threaded section, the outer sleeve is threadedly connected to the threaded section, the outer sleeve is provided with a radial threaded hole in the corresponding area of ​​the threaded section, and a fastening pin is threadedly connected in the threaded hole to lock the outer sleeve.

[0028] Furthermore, the inner wall of the upper end of the outer sleeve is provided with an inner step, and the outer wall of the upper end of the central tube is provided with an upward positioning step. The threaded section has the positioning step as its upper edge, and the inner step of the outer sleeve is engaged with the positioning step of the central tube.

[0029] Furthermore, the outer wall of the central tube below the threaded section and the inner wall of the outer sleeve below the threaded section achieve a mechanical seal through a clearance fit.

[0030] Compared with the prior art, the present invention has the following advantages:

[0031] 1. The central tube of this utility model features a spiral-shaped Tesla valve groove on its cylindrical surface, which enables unidirectional flow restriction, rapid forward injection, and flow restriction or even shut-off during reverse injection. This effectively avoids the risks of overflow and blowout caused by sudden increases in fracturing, and can limit and stabilize flow during oil well self-flowing oil and gas production, ensuring the safe exploitation of oil reservoirs.

[0032] 2. The groove structure of the Tesla valve of this utility model effectively prevents the intrusion of sand-containing fluids and acts as a sand screen during oil and gas production.

[0033] 3. This utility model improves the sand control effect while also increasing the fluid throughput.

[0034] 4. The selection and combination design of the four groove structures in this utility model improves the applicability of reservoir fluids. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure of an integrated fracturing and acidizing oil recovery screen pipe according to this utility model.

[0036] Figure 2 This is a cross-sectional schematic diagram of an integrated fracturing and acidizing oil recovery screen pipe according to Embodiment 1 of this utility model.

[0037] Figure 3 This is a cross-sectional schematic diagram of an integrated fracturing and acidizing oil recovery screen pipe in Embodiment 3 of this utility model.

[0038] Figure 4 This is a schematic diagram of the Tesla valve groove in Embodiment 1 of this utility model.

[0039] Figure 5 This is a schematic diagram of the Tesla valve groove in Embodiment 3 of this utility model.

[0040] In the figure: central tube 1; forward flow hole 101; Tesla valve groove 102; main flow channel 102l; p-type groove 102p; q-type groove 102q; b-type groove 102b; d-type groove 102d; outer sleeve 2; reverse flow hole 203. Detailed Implementation

[0041] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0042] Example 1:

[0043] Please see Figure 1 , Figure 2 , Figure 4 This utility model provides an integrated fracturing and acidizing oil production screen pipe, including a central pipe 2, an outer sleeve 3, and a Tesla valve groove 102 on the outer portion of the central pipe 2 covered by the outer sleeve 3. The Tesla valve groove 102 includes a main flow channel 102l and a branch flow channel located on the side of the main flow channel 102l. The main flow channel 102l is spiral-shaped. The central pipe 1 is provided with a forward flow hole 101 communicating with the main flow channel 102l, and the outer sleeve 2 is provided with a reverse flow hole 203 communicating with the main flow channel 102l. The branch flow channel makes the direction from the forward flow hole 101 to the reverse flow hole 203 the forward flow direction. By setting the main flow channel 102l of the Tesla valve groove 102 to be spiral-shaped, the utilization rate of the outer wall of the central pipe 2 is greatly improved. With the number of Tesla valve units between the forward flow hole 101 and the reverse flow hole 203 remaining unchanged, more forward flow holes 101 and reverse flow holes 203 can be arranged.

[0044] Specifically, the outer wall of the central tube 1 is provided with a threaded section, the outer sleeve 3 is threadedly connected to the threaded section, the outer sleeve 3 is provided with a radial threaded hole in the corresponding area of ​​the threaded section, and a fastening pin 202 is threadedly connected in the threaded hole to lock the outer sleeve 3.

[0045] Specifically, the inner wall of the upper end of the outer sleeve 3 is provided with an inner step 201, and the outer wall of the upper end of the central tube 1 is provided with an upward positioning step. The threaded section has the positioning step as its upper edge. During installation, the outer sleeve 3 and the central tube 1 are connected by threads, and the inner step 201 of the outer sleeve 3 is locked on the positioning step of the central tube 1 to achieve positioning.

[0046] Specifically, the outer wall of the central tube 2 below the threaded section and the inner wall of the outer sleeve 2 below the threaded section achieve a mechanical seal through a clearance fit.

[0047] Furthermore, the Tesla valve groove 102 includes at least one main channel 102l, one circumference of which is connected to at least one forward flow hole 101 and at least one reverse flow hole 203. The main channel has at least one branch channel between the forward flow hole 101 and the adjacent reverse flow hole 203. The forward flow holes 101 and the reverse flow holes 203 are arranged at intervals, and all the forward flow holes 101 and the reverse flow holes 203 are evenly distributed in the circumference of the main channel 102l.

[0048] Specifically, the forward flow holes 101 and reverse flow holes 203 are arranged in rows, and the number of rows is the same as the number of holes on one circumference of the main flow channel 102l, which facilitates processing.

[0049] Furthermore, the diversion channel includes a p-type groove 102p, a q-type groove 102q, a b-type groove 102b, and a d-type groove 102d, the vertical parts of the p-type groove 102p, the q-type groove 102q, the b-type groove 102b, and the d-type groove 102d all coincide with the main channel 102l.

[0050] Specifically, the branch channel located above the main channel 102l and facing downwards in the downstream direction is a p-shaped channel 102p.

[0051] Specifically, the branch channel located below the main channel 102l and facing downwards in the downstream direction is a q-shaped channel 102q.

[0052] Specifically, the branch channel located above the main channel 102l and facing upwards in the downstream direction is a type b channel 102b.

[0053] Specifically, the branch channel located below the main channel 102l and facing upwards in the downstream direction is a d-shaped channel 102d.

[0054] like Figure 2 , Figure 4 As shown, in an integrated fracturing and acidizing oil recovery screen pipe of this embodiment, four equidistant spiral main channels 102l are provided. Within one circumference of each main channel 102l, two forward flow holes 101 and two reverse flow holes 203 are connected. The forward flow holes 101 and reverse flow holes 203 are spaced 90° apart. The number of forward flow holes 101 and reverse flow holes 203 is the same. All forward flow holes 101 form two rows and are axially evenly distributed. All reverse flow holes 2021... 3. Two rows are formed and evenly distributed axially. The main channel 102l is provided with a p-type groove 102p and a q-type groove 102q between the forward flow hole 101 and the adjacent upper reverse flow hole 203. The p-type groove 102p is located above the q-type groove 102q. The main channel 102l is provided with a b-type groove 102b and a d-type groove 102d between the forward flow hole 101 and the adjacent lower reverse flow hole 203. The d-type groove 102d is located below the b-type groove 102b.

[0055] When the outer sleeve 2 and the center tube 1 are threaded together, when the inner step 201 of the outer sleeve 3 is engaged on the positioning step of the center tube 1, the main channel 102l between the reverse flow hole 203 and the b-type groove 102b and the q-type groove 102q of the outer sleeve 2 corresponds to the main channel 102l between the reverse flow hole 203 and the d-type groove 102d and the p-type groove 102p, and the fastening pin 202 is installed to lock it.

[0056] Example 2:

[0057] Based on Example 1, this example provides a method for using an integrated fracturing and acidizing oil recovery screen, including the following steps:

[0058] First, the screen pipe is lowered into the oil layer section where the operation is to be carried out along with the well tubing. Pressure fluid or reservoir acidizing fluid is pumped into the tubing from the surface. The fluid enters the Tesla valve groove 102 through the forward flow hole 101 of the central pipe 1, and then splits upward into the d-type groove 102d and the b-type groove 102b, and downward into the p-type groove 102p and the q-type groove 102q. Then, all of them enter the oil layer through the reverse flow hole 203 of the outer sleeve 2 to perform fracturing or acidizing of the oil reservoir.

[0059] When the pump stops at the surface and the pressure at the bottom of the well in the tubing decreases, the fluid in the oil reservoir enters the bottom of the well under the action of pressure difference. Due to the throttling effect of the Tesla valve groove 102, the flow rate of the fluid is constrained. Especially when the pressure difference is large and the flow rate is fast, it acts as a one-way valve to protect the safety of the oil well and the reservoir.

[0060] Once the pressure differential at the bottom of the well has stabilized, the reservoir fluid gradually enters the bottom of the well in a stable fluid state, and the oil pump in the well tubing operates to extract the oil from the bottom of the well to the surface.

[0061] Example 3:

[0062] Based on Example 1, this embodiment, for example Figure 3 , Figure 5 As shown, in an integrated fracturing and acidizing oil recovery screen pipe of this embodiment, four equidistant spiral main channels 102l are provided. Four forward flow holes 101 and four reverse flow holes 203 are connected within one circumference of the main channel 102l. The forward flow holes 101 and the reverse flow holes 203 are spaced 45° apart. The upper and lower ends of the main channel 102l are connected to the forward flow holes 101. The forward flow holes 101 have one more row than the reverse flow holes 203. All the forward flow holes 101 form four rows and are evenly distributed axially. All the reverse flow holes 203 form four rows and are evenly distributed axially. The main channel 102l is provided with a q-shaped groove 102q between the forward flow holes 101 and the adjacent upper reverse flow hole 203. The main channel 102l is provided with a b-shaped groove 102b between the forward flow holes 101 and the adjacent lower reverse flow hole 203.

[0063] This structure increases the number of forward flow holes 101 and reverse flow holes 203, improving fluid flowability.

[0064] All components not discussed in detail in this application, as well as the connection methods of these components, are well-known technologies in this field. They can be directly applied and will not be elaborated further.

[0065] In this utility model, the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "linking" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0066] In the description of this utility model, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or unit 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 this utility model.

[0067] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0068] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A fracturing and acidizing integrated screen pipe comprising a center pipe, the center pipe is externally sleeved with an outer sleeve, characterized in that, The portion of the outer wall of the central tube covered by the outer sleeve is provided with a Tesla valve groove; The Tesla valve recess includes a main flow channel and a branch flow channel disposed on the side of the main flow channel; The main channel is spiral-shaped, the central tube is provided with a forward flow hole communicating with the main channel, and the outer sleeve is provided with a reverse flow hole communicating with the main channel. The diversion channel makes the direction from the forward flow hole to the reverse flow hole the forward flow direction.

2. The fracturing and acidizing integrated screen pipe of claim 1, wherein, The Tesla valve recess includes at least one main channel; The main channel is connected to at least one forward flow hole and at least one reverse flow hole around its perimeter; the main channel has at least one branch channel between the forward flow hole and the adjacent reverse flow hole. The forward and reverse flow holes are arranged at intervals, and all forward and reverse flow holes are evenly distributed in the circumferential direction of the main flow channel.

3. The fracturing and acidizing integrated screen pipe of claim 2, wherein, The forward and reverse flow holes are arranged in separate rows, with the number of rows being the same as the number of holes on one circumference of the main flow channel.

4. The fracturing and acidizing integrated screen pipe of claim 2, wherein, The diversion channel includes a p-type groove, a q-type groove, a b-type groove, and a d-type groove, and the vertical parts of the p-type groove, q-type groove, b-type groove, and d-type groove all coincide with the main channel. The branch channel located above the main channel and facing downwards in the downstream direction is a p-shaped channel; The branch channel located below the main channel and facing downwards in the downstream direction is a Q-shaped channel; The branch channel located above the main channel and facing upwards in the downstream direction is a type B channel; The branch channel located below the main channel and facing upwards in the downstream direction is a d-shaped channel.

5. The fracturing and acidizing integrated screen pipe of claim 4, wherein, The main channel is provided with one or both of the following: a p-shaped groove and a q-shaped groove between the forward flow hole and the adjacent upper reverse flow hole. The main channel is provided with one or both of the following: a type B groove and a type D groove, between the forward flow hole and the adjacent downward reverse flow hole.

6. The fracturing and acidizing integrated screen pipe of claim 2, wherein, The number of forward flow holes and reverse flow holes is the same.

7. The fracturing and acidizing integrated screen pipe of claim 2, wherein, The forward or reverse flow hole is located at the upper or lower end of the main flow channel.

8. The fracturing and acidizing integrated screen pipe of claim 1, wherein, The outer wall of the central tube is provided with a threaded section, and the outer sleeve is threadedly connected to the threaded section. The outer sleeve is provided with a radial threaded hole in the corresponding area of ​​the threaded section, and a fastening screw is threadedly connected in the threaded hole to lock the outer sleeve.

9. The fracturing and acidizing integrated screen pipe of claim 8, wherein, The inner wall of the upper end of the outer sleeve is provided with an inner step, and the outer wall of the upper end of the central tube is provided with an upward positioning step. The threaded section has the positioning step as its upper edge, and the inner step of the outer sleeve is engaged with the positioning step of the central tube.

10. The fracturing and acidizing integrated screen pipe of claim 8, wherein, The outer wall of the central tube below the threaded section and the inner wall of the outer sleeve below the threaded section achieve a mechanical seal through a clearance fit.

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