Double-packer pressure-controlled multi-stage detonation perforation device and method

Abstract

The invention relates to the field of well completion oil testing perforation, in particular to a double-packer pressure-controlled multi-stage detonation perforation device and method. Comprising a first perforator unit, a second perforator unit and a third perforator unit which are all connected with an oil pipe, and the first perforator unit, the second perforator unit and the third perforator unit are conveyed into a target layer of an oil and gas well through the oil pipe; compared with the prior art, the tubular column inner flow direction control technology, the shaft liquid production channel control technology and the perforation test combined operation technology are integrated, oil testing operation of three different reservoir stratums can be completed only by tripping in the tubular column once, the oil testing time interval of the three reservoir stratums can be flexibly selected according to actual requirements, and the oil testing efficiency is improved. And the flexibility of the whole oil testing is improved.

Description

Technical Field

[0001] This invention relates to the field of well completion and oil testing perforation, specifically to a dual packer pressure-controlled multi-stage detonation perforation device and method. Background Technology

[0002] Perforation completion commonly employs a single-layer, single-test perforation and testing combined technique, where one layer is perforated at a time, tested, and then the tubing is pulled out before testing the next layer. This typically involves sealing with lime, resulting in a long construction period and high operating costs. Another technique is multi-layer perforation and testing combined, where multiple layers are perforated and tested simultaneously. However, this process can lead to biases in the testing data, making it difficult to accurately evaluate each layer. If multiple packers are used for layered testing, inter-layer pressure differences can cause interference, and packer stuck accidents have occurred. Precise testing is crucial for accurately evaluating different oil and gas reservoirs in oil and gas exploration, but completing multi-stage, independent layered perforation and testing with dual packers within the same tubing string is still not feasible.

[0003] By searching comparative documents on layered perforation testing, such as the patent "CN 105089514 A Layered Perforation Testing Tubing String and Its Usage Method" published by Zhang Youyi et al., this document discloses a layered perforation testing tubing string. Its core is to use the sliding sleeve action of the sealing valve to slide along the central pipe axis to achieve layered perforation and testing without shifting the tubing string or re-calibrating the depth after one trip of the tubing string is lowered into the oil well. The layered perforation testing tubing string of this invention can realize perforation and testing. This technology has the following main disadvantages in tubing string structure design and implementation method: (1) The test tubing string and sealing valve structure are complex, and the external pressure transmission pipe method is used, which has poor reliability; (2) The perforation gun detonation and sealing valve opening and closing are both pressure controlled, and the pressure gradient design is complex, which is prone to misoperation; (3) There are no actual field application cases, so the effectiveness of this technology cannot be proven. Summary of the Invention

[0004] To address the shortcomings of existing technologies, such as complex structures, poor reliability, and difficulty in engineering implementation, this invention proposes a dual-packer pressure-controlled multi-stage detonation perforation device and method. This method uses two packers to separate three test oil layers, and perforates the three layers sequentially. During this process, the fluids produced by the three test oil layers will not mix, enabling accurate analysis and evaluation of the three formations.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: This invention discloses a dual-packer pressure-controlled multi-stage detonation perforation device, comprising a first perforator unit, a second perforator unit, and a third perforator unit, all connected to tubing. The first, second, and third perforator units are transported to the target formation of an oil and gas well via tubing. A first packer is set between the first and second perforator units, and a second packer is set between the second and third perforator units. This device can separate the target formation of the oil and gas well into a first test layer, a second test layer, and a third test layer. The first, second, and third perforator units respectively perforate and test the first, second, and third test layers.

[0006] As a further improvement of the present invention, the first perforator unit includes a pressure release device, a first perforator, a first pressure delay detonation device, a flow direction control device, a pressure balance short section, a first shock absorber, and a first channel control device connected in sequence from bottom to top, wherein the first shock absorber and the first channel control device are separated by a first packer.

[0007] As a further improvement of the present invention, the flow control device includes a valve body, and at least one ball valve is provided in the valve body. One end of the ball valve is connected to a spring, and the other end is connected to a pressure cap for limiting the position of the ball valve.

[0008] As a further improvement of the present invention, the pressure balancing subsection is provided with a balancing hole for realizing the closing of the channel control device.

[0009] As a further improvement of the present invention, the second perforator unit includes a second perforator, a second pressure delay detonation device, a sand-preventing buffer device, a screen pipe joint, a second shock absorber, a pressure transmission joint, a sand-supporting cup, a pressure gauge, and a second channel control device connected in sequence from bottom to top, wherein the second shock absorber and the second channel control device are separated by a second packer.

[0010] As a further improvement of the present invention, a flow tube is connected between the screen tube joint and the pressure transmission joint.

[0011] As a further improvement of the present invention, the anti-sand-buffering device includes a nut, a long pressure-transmitting pipe, and a damping plate assembly; wherein one end of the long pressure-transmitting pipe extends into the damping plate assembly, and the other end is connected to the nut.

[0012] As a further improvement of the present invention, the third perforator unit includes a third perforator, a third pressure delay detonation device, a sand-preventing buffer device, a screen tube, and a depth-correcting short section connected in sequence from bottom to top.

[0013] As a further improvement of the present invention, the first packer is an RTTS packer and the second packer is a shear pin packer.

[0014] A method for a dual-packer pressure-controlled multi-stage detonation perforation device includes the following steps: S1. Connect this device to the tubing and use the tubing to transport the oil to the target layer of the oil and gas well. Adjust the tubing depth according to the depth of the depth correction section so that the first perforator unit, the second perforator unit, and the third perforator unit are facing the first test layer, the second test layer, and the third test layer. S2. The first perforator unit is used to perforate and test the first oil test layer, the second perforator unit is used to perforate and test the second oil test layer, and the third perforator unit is used to perforate and test the third oil test layer, so as to realize the analysis and evaluation of the three formations respectively.

[0015] Compared with the prior art, the present invention achieves the following technical effects: Compared with existing technologies, this invention integrates in-string flow control technology, wellbore production channel control technology, and perforation testing technology. It can complete oil testing operations for three different reservoirs with only one tubing string run, and the testing time interval for these three reservoirs can be flexibly selected according to actual needs, thus improving the overall flexibility of the oil testing.

[0016] The invention has a simple structure. The three perforator units are detonated using pressure gradient control or pressure pulse control, which ensures the accuracy and safety of the detonation. At the same time, the flow direction control technology in the tubing adopts an oil-casing pressure differential control single-flow valve structure, which realizes the integration of pressurized detonation and production channels, ensuring efficient execution of perforation operations and avoiding mutual interference between production channels.

[0017] The tubing production channel control technology in this invention adopts automatic control of the perforator detonation pressure, which ensures that the production of the three reservoirs can be completely independent and do not interfere with each other during a single tubing perforation test. This achieves the goal of fine-grained stratified oil testing and solves the technical problems of long cycle, high cost, serious formation pollution, and deviation in formation information acquisition during multi-layer joint testing in traditional perforation-testing combined construction.

[0018] Using this device not only significantly reduces the number of well washing, pressure, and plugging operations, further improving well control safety, but also, in practical applications, shortens the single-well oil testing cycle by 7-12 days, improves efficiency by 30-50%, and saves an average of over 2 million yuan in operating costs, further reducing costs. Attached Figure Description Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the flow direction control device of the present invention; Figure 3 This is a schematic diagram of the pressure balance short section structure of the present invention; Figure 4This is a schematic diagram of the anti-sand settling buffer device of the present invention.

[0019] Reference numerals: 1. Pressure relief device; 2. First perforator; 3a. First pressure delay detonation device; 3b. Second pressure delay detonation device; 3c. Third pressure delay detonation device; 4. Flow direction control device; 5. Pressure balance sub; 7a. First shock absorber; 7b. Second shock absorber; 8. First packer; 9a. First channel control device; 9b. Second channel control device; 10. Second perforator; 11a. First anti-sand settling buffer device; 11b. Second anti-sand settling buffer device; 12. Screen tube connector; 13. Second packer; 14. Pressure transmission connector; 15. Flow tube; 16. Sand support cup; 17. Pressure gauge; 18. Third perforator; 19. Screen tube; 20. Depth adjustment sub; 41. Ball valve; 42. Pressure cap; 43. Spring; 51. Balance hole; 111. Nut; 112. Long pressure transmission tube; 113. Damping plate assembly. Detailed Implementation

[0020] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0021] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element 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 invention.

[0022] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0023] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0024] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0025] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0026] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0027] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0028] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0029] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0030] like Figure 1 As shown, the present invention discloses a dual-packer pressure-controlled multi-stage detonation perforation device, comprising a first perforator unit, a second perforator unit, and a third perforator unit, all connected to an oil pipe. The first, second, and third perforator units are transported to the target formation of the oil and gas well via the oil pipe. A first packer 8 is set between the first and second perforator units, and a second packer 13 is set between the second and third perforator units. This can separate the target formation of the oil and gas well into a first test layer, a second test layer, and a third test layer. The first, second, and third perforator units respectively perforate and test the first, second, and third test layers.

[0031] like Figure 1 As shown in the embodiment, this device uses a tubing to transport the perforator and testing tools to an oil and gas well, which is a perforation testing joint string structure. The tubing is divided into four sections from top to bottom: 6a, 6b, 6c, and 6d. Each section of the tubing structure is equipped with different parts of the device, so that the first perforator unit, the second perforator unit, and the third perforator unit are respectively aligned with the three oil layers for perforation.

[0032] The first perforator unit includes, from bottom to top, a pressure release device 1, a first perforator 2, a first pressure delay detonation device 3a, a flow direction control device 4, a pressure balance section 5, a first shock absorber 7a, and a first channel control device 9a, wherein the first shock absorber 7a and the first channel control device 9a are separated by a first packer 8.

[0033] In this embodiment, the pressure relief device 1 releases the instantaneous high pressure generated when the perforating gun detonates in a confined space, specifically model SFZZ2-1; the first perforator 2 can perforate the first test oil layer, used for perforation operations at specific locations in oil and gas wells so that fluids (such as oil or natural gas) can flow into the wellbore. The perforator is a common existing technology, and its specific structure will not be described in detail; in this embodiment, the first pressure delay detonation device 3a can achieve detonation through pressure transmission, and the detonation time can be delayed; the first shock absorber 7a can reduce the vibration and impact generated during the perforation operation, protecting oil and gas well equipment and formation structure, specifically model HgMp-25C shock absorber.

[0034] The flow control device 4 includes a valve body, which contains at least one ball valve 41. One end of the ball valve 41 is connected to a spring 43, and the other end is connected to a pressure cap 42 for limiting the movement of the ball valve 41. Figure 2As shown, in this embodiment, the flow control device 4 controls the built-in ball valve 41 through the oil casing pressure difference. The ball valve 41 is a one-way switch. The pressure cap 42 can limit the ball valve 41, and the spring 43 controls the ball valve 41 to move. When the pressure is applied for detonation, the ball valve 41 in the device closes in the reverse direction. The perforation string and the casing of this device achieve reliable sealing. The flow control device 4 serves as a pressure transmission channel. The detonation pressure is used to activate the first pressure delay detonation device 3a. When the first perforator 2 detonates, the pressure difference between the casing and the tubing reaches 2MPa. At this time, the ball valve 41 opens in the forward direction, and the well fluid can enter the tubing unidirectionally from the casing annulus for production testing.

[0035] The pressure balancing section 5 is provided with a balancing hole 51 for closing the channel control device. For example... Figure 3 As shown, the pressure balancing sub 5 in the embodiment is used to cooperate with the channel control device in the first perforator 2 unit to achieve hole closing. The pressure balancing sub 5 is provided with a φ0.5 balance hole 51. When the channel control device is closed, it can squeeze the well fluid in the tubing between the first channel control device 9a and the pressure balancing sub 5, and release pressure through the balance hole 51 to avoid pressure buildup in the tubing, forming a closed space that prevents the channel control device from closing the hole.

[0036] The second perforator unit includes, from bottom to top, a second perforator 10, a second pressure delay detonation device 3b, a sand-preventing buffer device, a screen pipe joint 12, a second shock absorber 7b, a pressure transmission joint 14, a pressure gauge 17, and a second channel control device 9b, wherein the second shock absorber 7b and the second channel control device 9b are separated by a second packer 13.

[0037] In this embodiment, the second perforator 10 can perforate the second test layer, used for perforation operations at specific locations in the oil and gas well so that fluids (such as oil or natural gas) can flow into the wellbore; in this embodiment, the second pressure-delayed detonation device 3b can achieve detonation through pressure transmission, and the detonation time can be delayed; the second shock absorber 7b can reduce the vibration and impact generated during perforation operations, protecting oil and gas well equipment and formation structures, specifically the HgMp-25C shock absorber; the pressure gauge 17 is a device used to measure and record downhole pressure, used to monitor well conditions and ensure operational safety; the second channel control device 9b is used to control the flow channel of downhole fluid. A flow pipe 15 is connected between the screen pipe joint 12 and the pressure transmission joint 14. The flow pipe 15 in this embodiment is used to transmit pressure.

[0038] The anti-sand settling buffer device includes a nut 111, a long pressure transmission pipe 112, and a damping plate assembly 113; wherein one end of the long pressure transmission pipe 112 extends into the damping plate assembly 113, and the other end is connected to the nut 111. Figure 4As shown, the embodiment of the anti-sanding buffer device includes a first anti-sanding buffer device 11a and a second anti-sanding buffer device 11b. The first anti-sanding buffer device 11a is connected to the upper part of the second pressure delay detonation device 3b, and the second anti-sanding buffer device 11b is connected to the upper part of the third pressure delay detonation device 3c. It is used to prevent sand from affecting the transmission of pressurized pressure. The anti-sanding buffer device has a built-in long pressure transmission pipe 112, which extends into the upper part of the damping plate assembly 113. The damping plate assembly 113 can reduce the impact of well fluid pressure fluctuations on the shear pins of the second pressure delay detonation device 3b and the third pressure delay detonation device 3c in the second and third test oil layers.

[0039] The third perforator unit includes, from bottom to top, a third perforator 18, a third pressure-delayed detonation device 3c, a sand-preventing buffer device, a screen pipe 19, and a depth-correcting sub 20, connected sequentially. In this embodiment, the third perforator 18 can perforate the second test layer, used for perforation operations at specific locations in oil and gas wells so that fluids (such as oil or natural gas) can flow into the wellbore; in this embodiment, the third pressure-delayed detonation device 3c can achieve detonation through pressure transmission, and the detonation time can be delayed.

[0040] The first packer 8 is an RTTS packer, and the second packer 13 is a shear pin packer.

[0041] The present invention discloses a method for a dual-packer pressure-controlled multi-stage detonation perforation device, comprising the following steps: Connect each tool component in this device to the tubing at the wellhead, and use the tubing to transport the oil and gas well to the target formation. Measure the depth of the calibration sub 20 to determine the depth of the calibration sub 20. Adjust the tubing depth according to the depth of the calibration sub 20 so that the first perforator unit, the second perforator unit, and the third perforator unit are directly facing the first, second, and third test formations, respectively, and then separate them using the RTTS packer and the shear pin packer.

[0042] When the first perforator 2 unit is in operation, pressure is applied to the wellhead tubing. The pressure passes through the screen pipe 19 and enters the third perforator 18 in the third perforation unit, forming an annulus with the wellbore. It then descends, bypassing the third perforator 18 to the second channel control device 9b. From the bypass hole of the second channel control device 9b, it enters the tubing 6b of the first perforation unit, descends through the second packer 13, and re-enters the second perforator 10 in the second perforation unit at the screen pipe joint 12, forming an annulus with the wellbore. It then enters the tubing 6a through the first channel control device 9a, descends through the first packer 8, and the pressure is transmitted to the first pressure delay detonation device 3a in the first perforation unit, detonating the first perforator 2. Then, it enters the reservoir production test stage. The reservoir production fluid flows from the flow control device 4 into the tubing, reaching the wellhead via the reverse path of the positive pressure detonation.

[0043] After the first oil testing layer is completed, the second perforator 10 is detonated. The pressure enters the third perforator 18 in the third perforation unit and the annulus of the wellbore through the screen pipe 19, descends around the sand-supporting cup 16 to the pressure transmission joint 14, and reaches the second pressure delay detonation device 3b in the second perforation unit through the flow pipe 15 and the screen pipe joint 12, detonating the second perforator 10. The detonation pressure will close the production fluid channel of the first channel control device 9a connected to the lower end of the second perforator 10, preventing the reservoir production fluid of the first perforator 2 unit from mixing with the reservoir production fluid of the second perforator 10 unit, which would affect the analysis results. The reservoir of the second perforation unit then enters the production testing stage.

[0044] After the second perforation unit test is completed, the third perforator 18 in the third perforator 18 unit is detonated in the same way, and the second channel control device 9b for the reservoir production fluid outflow of the second perforator unit is closed. The reservoir of the third perforator 18 unit then enters the production test stage.

[0045] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0046] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A dual-packer pressure-controlled multi-stage detonation perforation device, characterized in that, It includes a first perforator unit, a second perforator unit, and a third perforator unit, all of which are connected to the tubing. The first perforator unit, the second perforator unit, and the third perforator unit are transported to the target layer of the oil and gas well through the tubing. The first perforator unit and the second perforator unit are sealed with a first packer (8), and the second perforator unit and the third perforator unit are sealed with a second packer (13). This can separate the target layer of the oil and gas well into a first test layer, a second test layer, and a third test layer. The first perforator unit, the second perforator unit, and the third perforator unit respectively perforate and test the first test layer, the second test layer, and the third test layer.

2. The dual-packer pressure-controlled multi-stage detonation perforation device according to claim 1, characterized in that, The first perforator unit includes, from bottom to top, a pressure relief device (1), a first perforator (2), a first pressure delay detonation device (3a), a flow direction control device (4), a pressure balance sub (5), a first shock absorber (7a), and a first channel control device (9a), wherein the first shock absorber (7a) and the first channel control device (9a) are separated by a first packer (8).

3. The dual-packer pressure-controlled multi-stage detonation perforation device according to claim 2, characterized in that, The flow control device (4) includes a valve body, which is provided with at least one ball valve (41). One end of the ball valve (41) is connected to a spring (43), and the other end is connected to a pressure cap (42) for limiting the ball valve (41).

4. The dual-packer pressure-controlled multi-stage detonation perforation device according to claim 2, characterized in that, The pressure balancing section (5) is provided with a balancing hole (51) for closing the channel control device.

5. The dual-packer pressure-controlled multi-stage detonation perforation device according to claim 1, characterized in that, The second perforator unit includes, from bottom to top, a second perforator (10), a second pressure delay detonation device (3b), a sand-preventing buffer device, a screen pipe joint (12), a second shock absorber (7b), a pressure transmission joint (14), a sand-supporting cup (16), a pressure gauge (17), and a second channel control device (9b), wherein the second shock absorber (7b) and the second channel control device (9b) are separated by a second packer (13).

6. The dual-packer pressure-controlled multi-stage detonation perforation device according to claim 5, characterized in that, A flow tube (15) is connected between the screen tube connector (12) and the pressure transmission connector (14).

7. The dual packer pressure-controlled multi-stage detonation perforation device according to claim 5, characterized in that, The anti-sand buffer device includes a nut (111), a long pressure transmission pipe (112), and a damping plate assembly (113); one end of the long pressure transmission pipe (112) extends into the damping plate assembly (113), and the other end is connected to the nut (111).

8. The dual-packer pressure-controlled multi-stage detonation perforation device according to claim 1, characterized in that, The third perforator unit includes a third perforator (18), a third pressure delay detonation device (3c), a sand-preventing buffer device, a screen tube (19), and a depth-correcting short section (20) connected in sequence from bottom to top.

9. The dual-packer pressure-controlled multi-stage detonation perforation device according to claim 1, characterized in that, The first packer (8) is an RTTS packer, and the second packer (13) is a shear pin packer.

10. A method for a dual-packer pressure-controlled multi-stage detonation perforation device according to any one of claims 1 to 9, characterized in that, Includes the following steps: S1. Connect this device to the tubing and use the tubing to transport the oil to the target layer of the oil and gas well. Adjust the tubing depth according to the depth of the depth correction section so that the first perforator unit, the second perforator unit, and the third perforator unit are facing the first test layer, the second test layer, and the third test layer. S2. The first perforator unit is used to perforate and test the first oil test layer, the second perforator unit is used to perforate and test the second oil test layer, and the third perforator unit is used to perforate and test the third oil test layer, so as to realize the analysis and evaluation of the three formations respectively.

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