Hydraulic pulse tool, pipe column tool string, and combined hydraulic perforation and fracturing method

Abstract

A hydraulic pulse tool (11), a pipe column tool string, and a combination hydraulic perforation and fracturing method, in the field of hydraulic perforation and fracturing. The hydraulic pulse tool (11) comprises a shell, an eccentric pipe (2), an impeller shaft (4), and a pulse impeller (3), the impeller shaft (4) extending perpendicular to a central axis of the shell. The eccentric pipe (2) has an eccentric hole disposed eccentrically relative to the central axis of the shell. Any two adjacent blades can define, with the eccentric pipe (2), a fluid cavity in communication with the eccentric hole, the volume of the fluid cavity changing as the pulse impeller (3) rotates. The present invention can implement a combined hydraulic pulse perforation and fracturing process for coiled tubing, and can form a continuous stress wave impact effect, improving a hydraulic jet perforation effect for coiled tubing. Moreover, the invention is capable of promoting rock fatigue damage during a fracturing process, reducing fracture initiation pressure, and comprehensively improving a fracturing effect.

Description

Hydraulic pulse tool, tubing tool string and hydraulic perforation and fracturing combined method

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Chinese patent application No. 202311252569.2 filed on September 26, 2023, the contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to the field of coiled tubing perforation and fracturing in oil and gas wells, and in particular to a hydraulic pulse tool, a tubing tool string, and a hydraulic pulse perforation and fracturing combined method. Background Art

[0004] Currently, hydraulic pulse technology is widely used in oil and gas resource development for water injection, drag reduction, and jet drilling. Hydraulic pulse fracturing is one of the hydraulic fracturing methods explored in recent years, and has achieved promising results in coal seam pulse fracturing for pressure relief and permeability enhancement.

[0005] Coiled tubing perforation and fracturing in oil and gas wells primarily involves pumping perforating fluid carrying perforating sand from a surface pump truck into the internal channels of the coiled tubing and string tools, and ejecting it through the nozzles of a hydraulic ejector to achieve hydraulic sandblasting perforation. Fracturing fluid carrying proppant is then pumped through the tubing or casing annulus to perform hydraulic fracturing. This is currently one of the primary technologies for staged fracturing in low-permeability oil and gas fields. The coiled tubing bottom seal drag fracturing string typically consists of a coiled tubing connector, a check valve, a safety joint, a rigid centralizer, a hydraulic ejector, a bottom packer, a casing collar locator, and a guide centralizer. Construction is carried out by running the coiled tubing into the wellbore.

[0006] Due to the large scale and complex processes involved in reservoir reconstruction in oil and gas fields, and the high flow path requirements of the working fluid carrying perforating sand and proppant, it is difficult to directly apply hydraulic pulse technology to the combined operation of coiled tubing perforation and fracturing in oil and gas wells. The core technology is the downhole hydraulic pulse tool. Most downhole hydraulic pulse tools, both domestically and internationally, are normally closed radial jet structures. The tools cannot be backwashed or recoiled properly, posing a significant construction risk when used in conjunction with fracturing. They are also not suitable for volume fracturing in tight oil and gas reservoirs or fine-segmented hydraulic jet fracturing with coiled tubing. In addition, the pulse tool has a relatively low flow rate, making it unsuitable for fracturing operations. Therefore, the pulse tool must be removed after the perforation process is completed before the fracturing process can be carried out.

[0007] Summary of the Invention

[0008] The purpose of the present invention is to overcome the problems of the hydraulic pulse tool in the prior art, such as being unsuitable for combined perforation and fracturing and having radial leakage.

[0009] In order to achieve the above-mentioned objectives, the present invention provides a hydraulic pulse tool on one hand, wherein the hydraulic pulse tool includes a tubular housing, an eccentric tube arranged in the housing, an impeller shaft arranged downstream of the eccentric tube, and a pulse impeller having multiple blades rotatably arranged on the impeller shaft, wherein the impeller shaft extends perpendicular to the central axis of the housing, the eccentric tube has an eccentric hole eccentrically arranged relative to the central axis of the housing, any two adjacent blades can form a fluid cavity connected to the eccentric hole with the eccentric tube, and the volume of the fluid cavity changes with the rotation of the pulse impeller.

[0010] In some embodiments, the central axis of the impeller shaft and the central axis of the housing intersect with each other, and the eccentric hole is provided on one side of a plane passing through the central axis of the impeller shaft and the central axis of the housing.

[0011] In some embodiments, a hemispherical concave surface is formed at the downstream end of the eccentric tube, and the blades can be clearance-fitted with the concave surface.

[0012] In some embodiments, a hemispherical upper concave surface is formed at the upstream end of the eccentric tube, and the eccentric hole is provided at the upper concave surface.

[0013] In some embodiments, a gradually expanding portion transitionally connected to the upper concave surface is provided in the shell.

[0014] In some embodiments, the hydraulic pulse tool includes a tubular support seat disposed downstream of the eccentric tube, the support seat having a through hole transitioning from the lower concave surface to the outlet of the housing.

[0015] In some embodiments, the through hole comprises a tapered hole, and a guide groove is provided on an inner surface of the tapered hole.

[0016] In some embodiments, the housing includes an upper joint and a lower joint that are detachably connected to each other.

[0017] On the other hand, the present solution also provides a tubing tool string, characterized in that the tubing tool string includes an oil pipe, a hydraulic ejector connected to the oil pipe, and the hydraulic pulse tool described in the above solution, and the hydraulic pulse tool is arranged upstream of the hydraulic ejector.

[0018] In some embodiments, the tubing tool string includes a continuous tubing connector, a one-way valve, a safety joint, a rigid centralizer, a bottom packer, a casing coupling locator, and a guide centralizer, which are arranged in sequence from top to bottom, and the hydraulic ejector and the hydraulic pulse tool are arranged between the rigid centralizer and the bottom packer.

[0019] On the other hand, this solution also provides a method for combined hydraulic pulse perforation and fracturing, comprising the following steps:

[0020] Lowering the tubing tool string into the well so that the hydraulic ejector reaches the target reservoir;

[0021] setting the bottom packer;

[0022] Perform hydraulic pulse sandblasting perforation;

[0023] Perform hydraulic fracturing.

[0024] In some embodiments, further comprising:

[0025] The tubing tool string is lifted so that the hydraulic ejector reaches other reservoirs, and after the bottom packer is set, hydraulic pulse sandblasting and perforation and hydraulic fracturing are performed respectively.

[0026] Through the above technical solution, the perforating fluid and fracturing fluid are pumped into the formation in the form of continuous pulse dynamic load through the tool, thereby generating alternating loads and forming a continuous stress wave impact effect; the tool has no radial leakage, which can significantly improve the effect of coiled tubing hydraulic jet perforation; the tool flow channel is unobstructed and continuous, which can support backwashing during construction; relying on the hydraulic pulse effect during the fracturing stage can: ① promote rock fatigue damage and reduce fracture initiation pressure; ② alternating loads create favorable conditions for inducing the formation of complex fracture networks; ③ strengthen the fracturing fluid sand carrying and sand spreading in the fracture, which is beneficial to fracture height control and comprehensively improves the fracturing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG1 is a cross-sectional view of a hydraulic pulse tool according to an embodiment of the present invention;

[0028] FIG2 is a schematic structural diagram of the eccentric tube and the pulse impeller according to an embodiment of the present invention;

[0029] FIG3 is a schematic diagram of the structure of the tubular tool according to an embodiment of the present invention.

[0030] DESCRIPTION OF REFERENCE NUMERALS 1 Upper joint 2 Eccentric tube 3 Pulse impeller 4 Impeller shaft 5 Support seat 6 Lower joint 7 Coiled tubing connector 8 Check valve 9 Safety joint 10 Rigid centralizer 11 Hydraulic pulse tool 12 Hydraulic ejector 13 Bottom packer 14 Casing coupling locator 15 Guide centralizer DETAILED DESCRIPTION

[0031] The following embodiments of the present disclosure are further described in detail with reference to the accompanying drawings and examples. The detailed description of the following examples and the accompanying drawings are intended to illustrate the principles of the present disclosure, but are not intended to limit the scope of the present disclosure. The present disclosure can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but rather includes all technical solutions within the scope of the claims.

[0032] The present disclosure provides these embodiments in order to make this disclosure thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that: unless otherwise specifically stated, the relative arrangement of parts and steps, the composition of materials, numerical expressions and numerical values ​​set forth in these embodiments should be interpreted as merely exemplary, and not as limiting.

[0033] It should be noted that, in the description of this disclosure, unless otherwise specified, "plurality" means greater than or equal to two; terms such as "upper," "lower," "left," "right," "inner," and "outer" indicating directions or positional relationships are intended solely to facilitate and simplify the description of this disclosure, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this disclosure. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0034] In addition, the terms "first," "second," and similar terms used in this disclosure do not denote any order, quantity, or importance, but are merely used to distinguish different parts. "Perpendicular" does not mean perpendicular in the strict sense, but rather means within the tolerance range. "Parallel" does not mean parallel in the strict sense, but rather means within the tolerance range. "Include" or "comprising" and similar terms mean that the elements preceding the term include the elements listed after the term, and do not exclude the possibility of also including other elements.

[0035] It should also be noted that, in the description of this disclosure, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in this disclosure depending on the specific circumstances. When a specific device is described as being located between a first device and a second device, there may or may not be an intervening device between the specific device and the first or second device.

[0036] All terms used in this disclosure have the same meaning as understood by one of ordinary skill in the art to which this disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in, for example, common dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and should not be interpreted in an idealized or highly formal sense, unless explicitly defined as such herein.

[0037] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0038] Example 1

[0039] Referring to Figures 1 and 2, the present solution provides a hydraulic pulse tool, wherein the hydraulic pulse tool includes a tubular shell, an eccentric tube 2 arranged in the shell, an impeller shaft 4 arranged downstream of the eccentric tube 2, and a pulse impeller 3 with multiple blades rotatably arranged on the impeller shaft 4, wherein the impeller shaft 4 extends perpendicular to the central axis of the shell, the eccentric tube 2 has an eccentric hole eccentrically arranged relative to the central axis of the shell, and any two adjacent blades can enclose a fluid cavity connected to the eccentric hole with the eccentric tube 2, and the volume of the fluid cavity changes with the rotation of the pulse impeller 3.

[0040] The hydraulic pulse tool can be used in a coiled tubing and convert the fluid passing through it into a pulsed fluid, so as to perform a perforation and fracturing combined process through the pulsed fluid.

[0041] In which, the shell can be used to be connected to the oil pipe to allow fluid to pass through. The eccentric tube 2 is provided with an eccentric hole so that the fluid flows therethrough eccentrically relative to the central axis of the shell. The pulse impeller 3 is rotatably arranged on the impeller shaft 4. When the fluid passing through the eccentric tube 2 reaches the pulse impeller 3, it can act on its blades to drive the pulse impeller 3 to rotate.

[0042] The pulse impeller 3 includes multiple blades. When two adjacent blades rotate to the side facing the eccentric tube 2, they can form a fluid cavity connected to the eccentric hole with the eccentric tube 2. During the rotation process, the fluid cavity changes from nothing to something and then to nothing, and its volume changes continuously, so that the flow rate of the fluid passing through the pulse impeller 3 also changes continuously, thereby forming a pulsed fluid.

[0043] In other words, the fluid passing through the eccentric tube 2 can act on the blades on one side of the pulse impeller 3, thereby driving the pulse impeller 3 to rotate continuously and periodically, and this periodic rotation in turn causes the fluid to form a periodically changing fluid.

[0044] Among them, the ratio of the inner diameter of the eccentric hole in the eccentric tube 2 to the inner diameter of the eccentric tube 2 can be relatively large, that is, the inner diameter of the eccentric hole is larger, which can ensure that the flow through the eccentric hole is at a larger level. Therefore, the tool can not only be used for hydraulic perforating operations, but also for fracturing operations with large flow requirements.

[0045] In this scheme, the perforating fluid and fracturing fluid are pumped into the formation in the form of continuous pulse dynamic loads through the tool, thereby generating alternating loads and forming a continuous stress wave impact effect. The tool does not have radial leakage, which can significantly improve the effectiveness of coiled tubing hydraulic jet perforation. During the fracturing stage, the hydraulic pulse effect can: ① promote rock fatigue damage and reduce the fracture initiation pressure; ② the alternating load creates favorable conditions for inducing the formation of complex fracture networks; ③ strengthen the fracturing fluid sand carrying and sand spreading in the fracture, which is beneficial to fracture height control and comprehensively improves the fracturing effect.

[0046] In some embodiments, the central axis of the impeller shaft 4 and the central axis of the housing intersect with each other, and the eccentric hole is provided on one side of a plane passing through the central axis of the impeller shaft 4 and the central axis of the housing. Referring to FIG1 , the central axis of the impeller shaft 4 and the central axis of the housing intersect perpendicularly with each other, and the eccentric hole is provided on the lower side of the plane passing through these two central axes. Fluid passing through the eccentric hole acts on the blades on the lower side of the pulse impeller 3, allowing the pulse impeller 3 to rotate continuously. The fluid is contained between two adjacent blades and flows periodically due to the periodic rotation of the pulse impeller 3, forming a pulsed fluid.

[0047] The eccentric hole may be tangent to a plane passing through the central axis of the impeller shaft 4 and the central axis of the housing, and the inner diameter of the eccentric hole is the same as the radius of the pulse impeller 3 .

[0048] As shown in FIG2 , the eccentric hole is a circular hole, and can also be a semicircular hole, so that the cross section of the eccentric hole reaches half of the maximum flow area of ​​the eccentric tube 2, thereby maximizing the flow area of ​​the eccentric hole to be compatible with fracturing operations.

[0049] The pulse impeller 3 may have a plurality of blades evenly distributed circumferentially, for example, three blades; of course, even if the plurality of blades are spaced at different angles in the circumferential direction, the pulse impeller 3 may also allow the fluid passing through to form a pulse fluid with periodically varying flow rate.

[0050] In some embodiments, a hemispherical lower concave surface is formed at the downstream end of the eccentric tube 2, and the blades are able to fit in the lower concave surface with a clearance. The blades of the impulse impeller 3 have arc-shaped edges, and the arc-shaped edges of the multiple blades are located in a concentric sphere, the center of which is the intersection of the central axis of the impeller shaft 4 and the central axis of the housing; and the center of the lower concave surface is also the intersection of the central axis of the impeller shaft 4 and the central axis of the housing. The arc-shaped edges of the blades fit in the lower concave surface with a clearance to allow the blades to slide relative to the lower concave surface.

[0051] In some embodiments, a hemispherical upper concave surface is formed at the upstream end of the eccentric tube 2, and the eccentric hole is provided at the upper concave surface. The concave structure formed around the eccentric hole of the eccentric tube 2 allows the fluid to transition through the smooth spherical surface when entering the eccentric hole, thereby preventing the fluid from forming turbulent flow there and causing excessive scouring of the eccentric tube 2.

[0052] The above describes the structure of the eccentric tube 2, which can be roughly cylindrical as a whole, with spherical concave surfaces formed at both ends, and then an eccentric hole is processed; the influence of the eccentric hole on its shape is not considered with respect to the spherical concave surface, which is only for the convenience of description, and those skilled in the art can understand the specific form of the concave surface.

[0053] In some embodiments, the housing is provided with a gradually expanding portion that transitions with the upper concave surface. As shown in Figure 1 , the portion of the housing that interfaces with the upper concave surface is gradually expanding, achieving a smooth transition from the smaller inner diameter of the housing to the larger inner diameter of the upper concave surface, thereby preventing turbulence and excessive scouring. Gradual expansion, as used herein, refers to a gradual increase in the inner diameter along the direction of fluid flow.

[0054] In addition, the hydraulic pulse tool includes a tubular support seat 5 arranged downstream of the eccentric tube 2, and the support seat 5 has a through hole that transitions from the lower concave surface to the outlet of the housing. The through hole of the support seat 5 allows fluid to pass through, and one end of the support seat 5 is connected to the eccentric tube 2, and the other end is connected to the outlet of the housing. Referring to Figure 1, it can be seen that the pulse impeller 3 is accommodated at the connection between the eccentric tube 2 and the support seat 5. The inner diameter of the outlet of the support seat 5 is smaller than the inner diameter of its inlet. The inner diameter of its inlet needs to be connected to the inner diameter of the lower concave surface of the eccentric tube 2, but the flow rate of the fluid passing through the eccentric tube 2 is limited by the eccentric hole. The inner diameter of the eccentric hole is only 1 / 2 or less of the lower concave surface. Therefore, the inner diameter of the outlet of the housing is relatively smaller to match the flow rate of the eccentric hole, and the inner diameter of the outlet of the support seat 5 is also correspondingly smaller.

[0055] The through hole includes a tapered hole, and a guide groove is provided on the inner surface of the tapered hole. The support seat 5 is provided with a tapered hole at its outlet end so that the inner diameter gradually transitions to a level that matches the outlet inner diameter of the shell. The tapering here refers to the gradual decrease in the inner diameter in the direction of fluid flow. The tapered portion can smoothly reduce the inner diameter, avoiding or alleviating the formation of turbulence in the fluid here and causing excessive scouring. In addition, the guide groove can guide the fluid to flow in a specific direction, avoiding the deposition of solid particles in the sand-containing perforating fluid at the tapered hole. A plurality of guide grooves, for example, three, can be provided at intervals in the circumferential direction.

[0056] In some embodiments, the housing includes an upper connector 1 and a lower connector 6 that are detachably connected to each other. The lower end of the upper connector 1 is inserted into the upper end of the lower connector 6. The lower end of the upper connector 1 can be externally threaded, and the upper end of the lower connector 6 can be internally threaded, allowing the upper connector 1 and the lower connector 6 to be threaded together. A sealing ring can be provided between the upper connector 1 and the lower connector 6 to improve the sealing between the two and prevent fluid leakage. In addition, the upper connector 1 and the lower connector 6 can be connected to each other by bolts to prevent them from accidentally disengaging.

[0057] Example 2

[0058] Referring to Figures 1 and 2, the present solution provides a hydraulic pulse tool, wherein the hydraulic pulse tool includes a tubular shell, an eccentric tube 2 arranged in the shell, an impeller shaft 4 arranged downstream of the eccentric tube 2, and a pulse impeller 3 with multiple blades rotatably arranged on the impeller shaft 4, wherein the impeller shaft 4 extends perpendicular to the central axis of the shell, the eccentric tube 2 has an eccentric hole eccentrically arranged relative to the central axis of the shell, and any two adjacent blades can enclose a fluid cavity connected to the eccentric hole with the eccentric tube 2, and the volume of the fluid cavity changes with the rotation of the pulse impeller 3.

[0059] The hydraulic pulse tool can be used in a coiled tubing to convert the fluid passing through it into a pulsed fluid, so as to perform a perforation and fracturing combined process through the pulsed fluid.

[0060] In which, the shell can be used to be connected to the oil pipe to allow fluid to pass through. The eccentric tube 2 is provided with an eccentric hole so that the fluid flows therethrough eccentrically relative to the central axis of the shell. The pulse impeller 3 is rotatably arranged on the impeller shaft 4. When the fluid passing through the eccentric tube 2 reaches the pulse impeller 3, it can act on its blades to drive the pulse impeller 3 to rotate.

[0061] The pulse impeller 3 includes multiple blades. When two adjacent blades rotate to the side facing the eccentric tube 2, they can form a fluid cavity connected to the eccentric hole with the eccentric tube 2. During the rotation process, the fluid cavity changes from nothing to something and then to nothing, and its volume changes continuously, so that the flow rate of the fluid passing through the pulse impeller 3 also changes continuously, thereby forming a pulsed fluid.

[0062] In other words, the fluid passing through the eccentric tube 2 can act on the blades on one side of the pulse impeller 3, thereby driving the pulse impeller 3 to rotate continuously and periodically, and this periodic rotation in turn causes the fluid to form a periodically changing fluid.

[0063] Among them, the ratio of the inner diameter of the eccentric hole in the eccentric tube 2 to the inner diameter of the eccentric tube 2 can be relatively large, that is, the inner diameter of the eccentric hole is larger, which can ensure that the flow through the eccentric hole is at a larger level. Therefore, the tool can not only be used for hydraulic perforating operations, but also for fracturing operations with large flow requirements.

[0064] In this scheme, the perforating fluid and fracturing fluid are pumped into the formation in the form of continuous pulse dynamic loads through the tool, thereby generating alternating loads and forming a continuous stress wave impact effect. The tool does not have radial leakage, which can significantly improve the effectiveness of coiled tubing hydraulic jet perforation. During the fracturing stage, the hydraulic pulse effect can: ① promote rock fatigue damage and reduce the fracture initiation pressure; ② the alternating load creates favorable conditions for inducing the formation of complex fracture networks; ③ strengthen the fracturing fluid sand carrying and sand spreading in the fracture, which is beneficial to fracture height control and comprehensively improves the fracturing effect.

[0065] In some embodiments, the central axis of the impeller shaft 4 and the central axis of the housing intersect with each other, and the eccentric hole is provided on one side of a plane passing through the central axis of the impeller shaft 4 and the central axis of the housing. Referring to FIG1 , the central axis of the impeller shaft 4 and the central axis of the housing intersect perpendicularly with each other, and the eccentric hole is provided on the lower side of the plane passing through these two central axes. Fluid passing through the eccentric hole acts on the blades on the lower side of the pulse impeller 3, allowing the pulse impeller 3 to rotate continuously. The fluid is contained between two adjacent blades and flows periodically due to the periodic rotation of the pulse impeller 3, forming a pulsed fluid.

[0066] The eccentric hole may be tangent to a plane passing through the central axis of the impeller shaft 4 and the central axis of the housing, and the inner diameter of the eccentric hole is the same as the radius of the pulse impeller 3 .

[0067] As shown in FIG2 , the eccentric hole is a circular hole, and can also be a semicircular hole, so that the cross section of the eccentric hole reaches half of the maximum flow area of ​​the eccentric tube 2, thereby maximizing the flow area of ​​the eccentric hole to be compatible with fracturing operations.

[0068] The pulse impeller 3 may have a plurality of blades evenly distributed circumferentially, for example, four blades; of course, even if the interval angles of the plurality of blades in the circumferential direction are different, the pulse impeller 3 may also make the fluid passing through form a pulse fluid with periodically changing flow rate.

[0069] In some embodiments, a hemispherical lower concave surface is formed at the downstream end of the eccentric tube 2, and the blades are able to fit in the lower concave surface with a clearance. The blades of the impulse impeller 3 have arc-shaped edges, and the arc-shaped edges of the multiple blades are located in a concentric sphere, the center of which is the intersection of the central axis of the impeller shaft 4 and the central axis of the housing; and the center of the lower concave surface is also the intersection of the central axis of the impeller shaft 4 and the central axis of the housing. The arc-shaped edges of the blades fit in the lower concave surface with a clearance to allow the blades to slide relative to the lower concave surface.

[0070] In some embodiments, a hemispherical upper concave surface is formed at the upstream end of the eccentric tube 2, and the eccentric hole is provided at the upper concave surface. The concave structure formed around the eccentric hole of the eccentric tube 2 allows the fluid to transition through the smooth spherical surface when entering the eccentric hole, thereby preventing the fluid from forming turbulent flow there and causing excessive scouring of the eccentric tube 2.

[0071] The above describes the structure of the eccentric tube 2, which can be roughly cylindrical as a whole, with spherical concave surfaces formed at both ends, and then an eccentric hole is processed; the influence of the eccentric hole on its shape is not considered with respect to the spherical concave surface, which is only for the convenience of description, and those skilled in the art can understand the specific form of the concave surface.

[0072] In some embodiments, the housing is provided with a gradually expanding portion that transitions with the upper concave surface. As shown in Figure 1 , the portion of the housing that interfaces with the upper concave surface is gradually expanding, achieving a smooth transition from the smaller inner diameter of the housing to the larger inner diameter of the upper concave surface, thereby preventing turbulence and excessive scouring. Gradual expansion, as used herein, refers to a gradual increase in the inner diameter along the direction of fluid flow.

[0073] In addition, the hydraulic pulse tool includes a tubular support seat 5 arranged downstream of the eccentric tube 2, and the support seat 5 has a through hole that transitions from the lower concave surface to the outlet of the housing. The through hole of the support seat 5 allows fluid to pass through, and one end of the support seat 5 is connected to the eccentric tube 2, and the other end is connected to the outlet of the housing. Referring to Figure 1, it can be seen that the pulse impeller 3 is accommodated at the connection between the eccentric tube 2 and the support seat 5. The inner diameter of the outlet of the support seat 5 is smaller than the inner diameter of its inlet. The inner diameter of its inlet needs to be connected to the inner diameter of the lower concave surface of the eccentric tube 2, but the flow rate of the fluid passing through the eccentric tube 2 is limited by the eccentric hole. The inner diameter of the eccentric hole is only 1 / 2 or less of the lower concave surface. Therefore, the inner diameter of the outlet of the housing is relatively smaller to match the flow rate of the eccentric hole, and the inner diameter of the outlet of the support seat 5 is also correspondingly smaller.

[0074] The through hole includes a tapered hole, and a guide groove is provided on the inner surface of the tapered hole. The support seat 5 is provided with a tapered hole at its outlet end so that the inner diameter gradually transitions to a level that matches the outlet inner diameter of the shell. The tapering here refers to the gradual decrease in the inner diameter in the direction of fluid flow. The tapered portion can smoothly reduce the inner diameter, avoiding or alleviating the formation of turbulence in the fluid here and causing excessive scouring. In addition, the guide groove can guide the fluid to flow in a specific direction, avoiding the deposition of solid particles in the sand-containing perforating fluid at the tapered hole. A plurality of guide grooves, for example, four, can be provided at intervals in the circumferential direction.

[0075] In some embodiments, the housing includes an upper connector 1 and a lower connector 6 that are detachably connected to each other. The lower end of the upper connector 1 is inserted into the upper end of the lower connector 6. The lower end of the upper connector 1 can be externally threaded, and the upper end of the lower connector 6 can be internally threaded, allowing the upper connector 1 and the lower connector 6 to be threaded together. A sealing ring can be provided between the upper connector 1 and the lower connector 6 to improve the sealing between the two and prevent fluid leakage. In addition, the upper connector 1 and the lower connector 6 can be connected to each other by bolts to prevent them from accidentally disengaging.

[0076] Example 3

[0077] Referring to Figures 1 and 2, the present solution provides a hydraulic pulse tool, wherein the hydraulic pulse tool includes a tubular shell, an eccentric tube 2 arranged in the shell, an impeller shaft 4 arranged downstream of the eccentric tube 2, and a pulse impeller 3 with multiple blades rotatably arranged on the impeller shaft 4, wherein the impeller shaft 4 extends perpendicular to the central axis of the shell, the eccentric tube 2 has an eccentric hole eccentrically arranged relative to the central axis of the shell, and any two adjacent blades can enclose a fluid cavity connected to the eccentric hole with the eccentric tube 2, and the volume of the fluid cavity changes with the rotation of the pulse impeller 3.

[0078] The hydraulic pulse tool can be used in a coiled tubing and convert the fluid passing through it into a pulsed fluid, so as to perform a perforation and fracturing combined process through the pulsed fluid.

[0079] In which, the shell can be used to be connected to the oil pipe to allow fluid to pass through. The eccentric tube 2 is provided with an eccentric hole so that the fluid flows therethrough eccentrically relative to the central axis of the shell. The pulse impeller 3 is rotatably arranged on the impeller shaft 4. When the fluid passing through the eccentric tube 2 reaches the pulse impeller 3, it can act on its blades to drive the pulse impeller 3 to rotate.

[0080] The pulse impeller 3 includes multiple blades. When two adjacent blades rotate to the side facing the eccentric tube 2, they can form a fluid cavity connected to the eccentric hole with the eccentric tube 2. During the rotation process, the fluid cavity changes from nothing to something and then to nothing, and its volume changes continuously, so that the flow rate of the fluid passing through the pulse impeller 3 also changes continuously, thereby forming a pulsed fluid.

[0081] In other words, the fluid passing through the eccentric tube 2 can act on the blades on one side of the pulse impeller 3, thereby driving the pulse impeller 3 to rotate continuously and periodically, and this periodic rotation in turn causes the fluid to form a periodically changing fluid.

[0082] Among them, the ratio of the inner diameter of the eccentric hole in the eccentric tube 2 to the inner diameter of the eccentric tube 2 can be relatively large, that is, the inner diameter of the eccentric hole is larger, which can ensure that the flow through the eccentric hole is at a larger level. Therefore, the tool can not only be used for hydraulic perforating operations, but also for fracturing operations with large flow requirements.

[0083] In this scheme, the perforating fluid and fracturing fluid are pumped into the formation in the form of continuous pulse dynamic loads through the tool, thereby generating alternating loads and forming a continuous stress wave impact effect. The tool does not have radial leakage, which can significantly improve the effectiveness of coiled tubing hydraulic jet perforation. During the fracturing stage, the hydraulic pulse effect can: ① promote rock fatigue damage and reduce the fracture initiation pressure; ② the alternating load creates favorable conditions for inducing the formation of complex fracture networks; ③ strengthen the fracturing fluid sand carrying and sand spreading in the fracture, which is beneficial to fracture height control and comprehensively improves the fracturing effect.

[0084] In some embodiments, the central axis of the impeller shaft 4 and the central axis of the housing intersect with each other, and the eccentric hole is provided on one side of a plane passing through the central axis of the impeller shaft 4 and the central axis of the housing. Referring to FIG1 , the central axis of the impeller shaft 4 and the central axis of the housing intersect perpendicularly with each other, and the eccentric hole is provided on the lower side of the plane passing through these two central axes. Fluid passing through the eccentric hole acts on the blades on the lower side of the pulse impeller 3, allowing the pulse impeller 3 to rotate continuously. The fluid is contained between two adjacent blades and flows periodically due to the periodic rotation of the pulse impeller 3, forming a pulsed fluid.

[0085] The eccentric hole may be tangent to a plane passing through the central axis of the impeller shaft 4 and the central axis of the housing, and the inner diameter of the eccentric hole is the same as the radius of the pulse impeller 3 .

[0086] As shown in FIG2 , the eccentric hole is a circular hole, and can also be a semicircular hole, so that the cross section of the eccentric hole reaches half of the maximum flow area of ​​the eccentric tube 2, thereby maximizing the flow area of ​​the eccentric hole to be compatible with fracturing operations.

[0087] The pulse impeller 3 may have a plurality of blades evenly distributed circumferentially, for example, 5 blades; of course, even if the plurality of blades are spaced at different angles in the circumferential direction, the pulse impeller 3 may also allow the fluid passing through to form a pulse fluid with periodically varying flow rate.

[0088] In some embodiments, a hemispherical lower concave surface is formed at the downstream end of the eccentric tube 2, and the blades are able to fit in the lower concave surface with a clearance. The blades of the impulse impeller 3 have arc-shaped edges, and the arc-shaped edges of the multiple blades are located in a concentric sphere, the center of which is the intersection of the central axis of the impeller shaft 4 and the central axis of the housing; and the center of the lower concave surface is also the intersection of the central axis of the impeller shaft 4 and the central axis of the housing. The arc-shaped edges of the blades fit in the lower concave surface with a clearance to allow the blades to slide relative to the lower concave surface.

[0089] In some embodiments, a hemispherical upper concave surface is formed at the upstream end of the eccentric tube 2, and the eccentric hole is provided at the upper concave surface. The concave structure formed around the eccentric hole of the eccentric tube 2 allows the fluid to transition through the smooth spherical surface when entering the eccentric hole, thereby preventing the fluid from forming turbulent flow there and causing excessive scouring of the eccentric tube 2.

[0090] The above describes the structure of the eccentric tube 2, which can be roughly cylindrical as a whole, with spherical concave surfaces formed at both ends, and then an eccentric hole is processed; the influence of the eccentric hole on its shape is not considered with respect to the spherical concave surface, which is only for the convenience of description, and those skilled in the art can understand the specific form of the concave surface.

[0091] In some embodiments, the housing is provided with a gradually expanding portion that transitions with the upper concave surface. As shown in Figure 1 , the portion of the housing that interfaces with the upper concave surface is gradually expanding, achieving a smooth transition from the smaller inner diameter of the housing to the larger inner diameter of the upper concave surface, thereby preventing turbulence and excessive scouring. Gradual expansion, as used herein, refers to a gradual increase in the inner diameter along the direction of fluid flow.

[0092] In addition, the hydraulic pulse tool includes a tubular support seat 5 arranged downstream of the eccentric tube 2, and the support seat 5 has a through hole that transitions from the lower concave surface to the outlet of the housing. The through hole of the support seat 5 allows fluid to pass through, and one end of the support seat 5 is connected to the eccentric tube 2, and the other end is connected to the outlet of the housing. Referring to Figure 1, it can be seen that the pulse impeller 3 is accommodated at the connection between the eccentric tube 2 and the support seat 5. The inner diameter of the outlet of the support seat 5 is smaller than the inner diameter of its inlet. The inner diameter of its inlet needs to be connected to the inner diameter of the lower concave surface of the eccentric tube 2, but the flow rate of the fluid passing through the eccentric tube 2 is limited by the eccentric hole. The inner diameter of the eccentric hole is only 1 / 2 or less of the lower concave surface. Therefore, the inner diameter of the outlet of the housing is relatively smaller to match the flow rate of the eccentric hole, and the inner diameter of the outlet of the support seat 5 is also correspondingly smaller.

[0093] The through hole includes a tapered hole, and a guide groove is provided on the inner surface of the tapered hole. The support seat 5 is provided with a tapered hole at its outlet end so that the inner diameter gradually transitions to a level that matches the outlet inner diameter of the shell. The tapered portion here refers to the gradual decrease in the inner diameter in the direction of fluid flow. The tapered portion can smoothly reduce the inner diameter, avoiding or alleviating the formation of turbulence in the fluid here and causing excessive scouring. In addition, the guide groove can guide the fluid to flow in a specific direction, avoiding the deposition of solid particles in the sand-containing perforating fluid at the tapered hole. A plurality of guide grooves, for example, 5, can be provided at intervals in the circumferential direction.

[0094] In some embodiments, the housing includes an upper connector 1 and a lower connector 6 that are detachably connected to each other. The lower end of the upper connector 1 is inserted into the upper end of the lower connector 6. The lower end of the upper connector 1 can be externally threaded, and the upper end of the lower connector 6 can be internally threaded, allowing the upper connector 1 and the lower connector 6 to be threaded together. A sealing ring can be provided between the upper connector 1 and the lower connector 6 to improve the sealing between the two and prevent fluid leakage. In addition, the upper connector 1 and the lower connector 6 can be connected to each other by bolts to prevent them from accidentally disengaging.

[0095] On the other hand, the present solution provides a tubing tool string, wherein the tubing tool string includes a tubing, a hydraulic ejector 12 connected to the tubing, and the hydraulic pulse tool 11 described in the above solution, wherein the hydraulic pulse tool 11 is disposed upstream of the hydraulic ejector 12. The hydraulic pulse tool 11 can pulse a perforating fluid or a fracturing fluid, and inject the perforating fluid or the fracturing fluid into the reservoir through the hydraulic ejector 12 to perform a perforating or fracturing operation.

[0096] In addition, referring to Figure 3, the tubing tool string includes a coiled tubing connector 7, a one-way valve 8, a safety joint 9, a rigid centralizer 10, a bottom packer 13, a casing coupling locator 14, and a guide centralizer 15, which are arranged in sequence from top to bottom. The hydraulic ejector 12 and the hydraulic pulse tool 11 are arranged between the rigid centralizer 10 and the bottom packer 13.

[0097] On the other hand, this solution also provides a method for combined hydraulic pulse perforation and fracturing, comprising the following steps:

[0098] Lower the tubing tool string described in the above solution into the well so that the hydraulic ejector 12 reaches the target reservoir;

[0099] Setting the bottom packer 13;

[0100] Perform hydraulic pulse sandblasting perforation;

[0101] Perform hydraulic fracturing.

[0102] The tubing tool string is lowered into the target depth of the well so that the hydraulic ejector 12 is located at the target reservoir, thereby enabling perforation and fracturing operations to be performed.

[0103] In addition, the hydraulic pulse perforation and fracturing combined method also includes:

[0104] The tubing tool string is lifted so that the hydraulic ejector 12 reaches other reservoirs. After the bottom packer 13 is set, hydraulic pulse sandblasting and hydraulic fracturing are performed respectively.

[0105] Of course, in some cases, there may be multiple reservoirs in the formation, and the hydraulic ejector 12 may be lowered into the lowest reservoir first. Then, the tubing string is raised to allow the hydraulic ejector 12 to ascend to the adjacent reservoir above, and after the bottom packer 13 is set, hydraulic pulse sandblasting perforation and hydraulic fracturing are performed again; this cycle is repeated to perforate and fracture all reservoirs.

[0106] This solution can realize the combined process of coiled tubing hydraulic pulse perforation and fracturing. The tool has a simple structure, a large channel, and high transmission efficiency. Backwashing can be performed during the fracturing process, and there is no radial leakage. A continuous stress wave impact effect can be formed, which can significantly improve the effect of coiled tubing hydraulic jet perforation. During the fracturing process, it can promote rock fatigue damage, reduce the fracture initiation pressure, induce microcracks and gradually connect and penetrate natural fractures, thereby forming an effective volume fracture network and comprehensively improving the fracturing effect.

[0107] Thus far, various embodiments of the present disclosure have been described in detail. To avoid obscuring the concept of the present disclosure, some details known in the art have not been described. Based on the above description, those skilled in the art can fully understand how to implement the technical solutions disclosed herein.

[0108] Although some specific embodiments of the present disclosure have been described in detail through examples, those skilled in the art will understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Those skilled in the art will understand that the above embodiments may be modified or some technical features may be replaced with equivalents without departing from the scope and spirit of the present disclosure. In particular, as long as there are no structural conflicts, the various technical features mentioned in the various embodiments may be combined in any manner.

Claims

1. A hydraulic pulse tool, characterized in that: The hydraulic pulse tool comprises a tubular housing, an eccentric tube (2) arranged in the housing, an impeller shaft (4) arranged downstream of the eccentric tube (2), and a pulse impeller (3) having a plurality of blades rotatably arranged on the impeller shaft (4), wherein the impeller shaft (4) extends perpendicular to the central axis of the housing, the eccentric tube (2) has an eccentric hole eccentrically arranged relative to the central axis of the housing, any two adjacent blades can enclose a fluid cavity connected to the eccentric hole with the eccentric tube (2), and the volume of the fluid cavity changes with the rotation of the pulse impeller (3); The central axis of the impeller shaft (4) and the central axis of the housing intersect each other, and the eccentric hole is arranged on one side of a plane passing through the central axis of the impeller shaft (4) and the central axis of the housing; Wherein, a hemispherical lower concave surface is formed at the downstream end of the eccentric tube (2), and the blades can be clearance-matched with the lower concave surface.

2. The hydraulic pulse tool according to claim 1, characterized in that: The upstream end of the eccentric tube (2) is formed with a hemispherical upper concave surface, and the eccentric hole is arranged on the upper concave surface.

3. The hydraulic pulse tool according to claim 2, characterized in that: The shell body is provided with a gradually expanding portion transitionally connected with the upper concave surface.

4. The hydraulic pulse tool according to claim 1, characterized in that: The hydraulic pulse tool comprises a tubular support seat (5) arranged downstream of the eccentric tube (2), and the support seat (5) has a through hole transitioning from the lower concave surface to the outlet of the housing.

5. The hydraulic pulse tool according to claim 4, characterized in that: The through hole comprises a tapered hole, and a guide groove is arranged on the inner surface of the tapered hole.

6. The hydraulic pulse tool according to claim 4, characterized in that: The housing comprises an upper joint (1) and a lower joint (6) which are detachably connected to each other.

7. A tubular tool string, characterized in that: The tubing tool string comprises an oil pipe, a hydraulic ejector (12) connected to the oil pipe, and a hydraulic pulse tool (11) according to any one of claims 1 to 6, wherein the hydraulic pulse tool (11) is arranged upstream of the hydraulic ejector (12).

8. The tubular tool string according to claim 7, characterized in that: The tubing tool string comprises a continuous tubing connector (7), a one-way valve (8), a safety joint (9), a rigid centralizer (10), a bottom packer (13), a casing coupling positioner (14), and a guide centralizer (15) which are arranged in sequence from top to bottom. The hydraulic ejector (12) and the hydraulic pulse tool (11) are arranged between the rigid centralizer (10) and the bottom packer (13).

9. A hydraulic pulse perforation and fracturing combined method, characterized in that: The following steps are involved: Lowering the tubing tool string of claim 8 into the well so that the hydraulic ejector (12) reaches the target reservoir; Setting the bottom packer (13); Perform hydraulic pulse sandblasting perforation; Perform hydraulic fracturing.

10. The hydraulic pulse perforation and fracturing combined method according to claim 9, characterized in that: Also includes: The tubing tool string is lifted so that the hydraulic ejector (12) reaches other reservoirs, and after the bottom packer (13) is set, hydraulic pulse sandblasting perforation and hydraulic fracturing are performed respectively.

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