A push-type laser perforating device

Abstract

The present invention proposes a push-type laser perforating device, comprising a downhole execution part, including a short section, on which a depth measuring device for measuring downhole depth is provided; a pusher connected to the side wall of the short section body, the pusher being configured to be able to be extended and to push the end thereof against the position of the casing wall; a laser perforator connected to the end of the pusher, the laser perforator performing perforating operations by means of laser; and a ground control part, the ground control part being connected to the downhole execution part via a cable of a perforating winch, and controlling the downhole execution part to be lowered to a predetermined position, rotated at an angle, and to perform perforating operations; and providing electrical energy to the downhole execution part.

Description

Technical Field

[0001] The invention relates to a push-type laser perforating device, belonging to the technical field of perforating in oil and natural gas drilling. Background Art

[0002] In the field of oil and gas drilling perforation technology, traditional perforating methods include bullet perforators, torpedo perforators, and focused energy perforators. Although these methods have undergone several improvements and developments, their fundamental principle remains the same: perforating through rock by squeezing it creates oil and gas pathways. Compared to traditional perforating methods, laser perforating offers the following advantages: While conventional perforating methods reduce permeability due to the compaction effect, the thermal effect of the laser on the perforation wall increases permeability, facilitating oil and gas seepage. Laser perforation also forms a ceramic layer on the rock, creating a smooth, non-collapse-resistant perforation surface. Laser perforation melts and vaporizes the rock formation, reducing sand production and the cost of on-site sand control measures, thereby generating higher economic returns for the oilfield. Traditional perforating methods rely on forced mechanical destruction of the rock, which can easily crack the perforation wall and cause rock collapse. Furthermore, with increasing laser power and its excellent directionality, perforation depth can be guaranteed.

[0003] The laser perforation technology currently proposed is still in the research stage or has not been promoted due to limited conditions. The main reason is that the high-power lasers under development are too large, and the power of existing lasers (1000W) is insufficient. At the same time, a large amount of energy is lost in the process of penetrating the mud, and the appropriate perforation depth cannot be achieved. Summary of the Invention

[0004] In response to the above-mentioned technical problems existing in the prior art, the present invention proposes a push-type laser perforating device, which is divided into an underground execution part and a ground control part. The laser perforator is set underground, and the power supply for providing it with electrical energy is set on the ground. The split approach reduces the space occupied underground and can also be achieved after increasing the laser power.

[0005] The present invention proposes a push-type laser perforating device, comprising:

[0006] Downhole execution part, including

[0007] a short sub provided with a depth measuring device for measuring the downhole depth;

[0008] A pusher connected to the side wall of the short section body is configured to be able to be extended and push the end portion against the position of the casing wall.

[0009] a laser perforator connected to the end of the pusher, the laser perforator performing perforation operation by laser; and

[0010] The ground control part is connected to the downhole execution part through the cable of the perforating winch, and controls the downhole execution part to be lowered to a predetermined position, rotated at an angle, and performs perforating operations; and provides electrical energy to the downhole execution part.

[0011] A further improvement of the present invention is that the ground control part includes a control device, which includes: a lowering control unit, which controls the perforating winch to lower the downhole execution part to a predetermined position via a cable; a rotation control unit, which controls the rotation of the pusher; and a pushing control unit, which controls the pusher to push the laser perforator against the casing wall.

[0012] A further improvement of the present invention is that the ground control part also includes a power supply device, which includes: a system power supply, which provides power to the lowering control unit, the rotation control unit and the pushing control unit; a control unit, which provides power to the pushing device and the depth measuring device through a cable; and a perforating high-voltage power supply, which provides power to the laser perforator through a cable.

[0013] A further improvement of the present invention is that the laser perforator includes a pressure-resistant cylinder, the outer wall of which is an arc-shaped that matches the casing wall; a laser emitting probe is provided in the pressure-resistant cylinder, and the laser emitting probe receives electrical energy provided by the perforating high-voltage power supply through a high-voltage probe.

[0014] A further improvement of the present invention is that a perforation window needle is provided on the pressure-resistant cylinder wall, and the perforation window needle constrains the laser beam emitted by the laser emission probe.

[0015] A further improvement of the present invention is that the pressure-resistant cylinder is filled with an elastic filling member, and the elastic filling member is coated on the outside of the laser emitting probe.

[0016] A further improvement of the present invention is that the elastic filling piece is a rubber filling body.

[0017] A further improvement of the present invention is that the outer side of the high-voltage probe is covered with a ceramic tube.

[0018] A further improvement of the present invention is that a downhole control unit is provided on the short section, and the downhole control unit receives instructions from the rotation control unit and the pushing control unit, and controls the pushing device to complete the pushing and rotating actions.

[0019] A further improvement of the present invention is that the depth measuring device is a natural gamma ray logging instrument.

[0020] Compared with the prior art, the advantages of the present invention are:

[0021] The push-type laser perforating device of the present invention is divided into a downhole execution part and a ground control part. The laser perforator is arranged downhole, and the power supply for providing electric energy to the laser perforator is arranged on the ground. The split type reduces the space occupied downhole, makes the size of the laser suitable, and increases the types of uses of the laser.

[0022] When the push-type laser perforating device of the present invention is in operation, the pusher pushes the laser perforator to the casing wall and then starts perforating, so that the single-wavelength strong laser beam does not need to pass through the mud flow channel and directly penetrates the casing and cement sheath into the reservoir rock, greatly improving the perforating efficiency. Indirectly, the power requirement of the laser perforator can be greatly reduced, and the corresponding laser size can be effectively controlled. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0024] Figure 1 FIG2 is a schematic structural diagram of a push-type laser perforating device according to an embodiment of the present invention;

[0025] Figure 2 Shown is a schematic structural diagram of a laser generator according to an embodiment of the present invention;

[0026] Figure 3 Shown is a schematic structural diagram of a downhole execution part of an embodiment of the present invention.

[0027] In the drawings, like components are denoted by like reference numerals, but the drawings are not necessarily drawn to scale.

[0028] The meanings of the reference numerals in the accompanying drawings are as follows: 1. Downhole execution part, 2. Ground control part, 3. Casing, 11. Depth measuring device, 12. Pusher, 13. Laser perforator, 14. Downhole control unit, 15. Pressure-resistant cylinder, 16. Laser emission probe, 17. High-pressure probe, 18. Perforating window needle, 19. Elastic filling part, 21. Control device, 22. Power supply device, 31. Formation, 32. Mud. DETAILED DESCRIPTION

[0029] To make the technical solutions and advantages of the present invention more clearly understood, exemplary embodiments of the present invention are further described in detail below with reference to the accompanying drawings. It should be understood that the described embodiments are only a portion of the embodiments of the present invention, and are not exhaustive. Furthermore, the embodiments and features of the embodiments of the present invention may be combined with each other unless there is a conflict.

[0030] FIG1 schematically shows a push-type laser perforating device according to an embodiment of the present invention, comprising a downhole execution part 1 and a surface control part 2 .

[0031] The downhole execution part 1 is lowered into the well with the cable winch and performs perforation operations according to the control instructions of the ground control part 2. The downhole execution part 1 includes a short section, on which a depth measuring device 11 is provided. The depth measuring device 11 is used to measure the depth of the well. The downhole execution part 1 also includes a pusher 12, which is connected to the short section and is constructed to be able to be extended in the radial direction of the casing. After extension, the end of the pusher 12 is pushed against the position of the casing wall. The power for extending the pusher 12 can be hydraulic or electric. A laser perforator 13 is provided at the end of the pusher 12, which pushes the laser perforator 13 against the casing wall when extended.

[0032] The surface control unit 2 is located above the wellbore and can be installed in the operator's room of the perforating winch. The surface control unit 2 is connected to the downhole actuator 1 via a cable from the perforating winch. The cable provides communication and power, inputting control commands to the downhole actuator 1 and supplying power. The surface control unit 2 issues commands and controls the perforating winch to lower the downhole actuator 1 to the desired position. It also controls the rotation angle of the sub or pusher 12, and subsequently controls the laser perforator 13 to perform the perforating operation.

[0033] When using the push-and-pull laser perforating device described in this embodiment, the surface control unit 2 controls the downhole actuator 1 to perform perforation. First, the surface control unit 2 controls the perforating winch to lower the downhole actuator 1 to a predetermined position underground. It then controls the rotary pusher 12 to rotate to an appropriate angle. Pusher 12 then extends and pushes the laser perforator 13 against the casing wall. Laser perforator 13 performs the perforation operation. After completion, pusher 12 is controlled to rotate again and push against the laser perforator 13 to perform the perforation operation at a different angle.

[0034] In one embodiment, the surface control unit 2 includes a control device 21, which includes a lowering control unit, a rotation control unit, and a pushing control unit. The lowering control unit is used to control the perforating winch to lower the downhole implement 1 to a predetermined position. The rotation control unit controls the rotation of the pup joint or pusher 12, so that the end of the pusher 12 (the laser perforator 13) faces the desired perforation direction. The pushing control unit controls the extension of the pusher 12 and pushes the laser perforator 13 against the casing wall.

[0035] When using the push-and-pull laser perforating device described in this embodiment, personnel control the movement of the downhole actuator 1 via the surface control unit 2. First, the lowering control unit controls the perforating winch to lower the downhole actuator 1 to the appropriate position. The approximate position of the lowering position can be determined based on the length of the winch lowering. The depth is then verified using the depth measurement device 11 to determine whether the downhole actuator 1 has moved to the appropriate position. Next, the rotation control unit controls the rotation of the nipple or pusher 12, aligning the laser perforator 13 in the desired perforating direction. The pusher control unit then controls the extension of the pusher 12, pushing the laser perforator 13 against the casing wall, and then perforating.

[0036] In one embodiment, the surface control unit 2 further includes a power supply unit 22, which includes a system power supply, a control unit, and a perforating high-voltage power supply. The system power supply provides power to the lowering control unit, rotation control unit, and pushing unit of the surface control unit 2. The control unit provides power to the pushing unit 12 and depth measurement device 11 via a cable, providing power to all components of the downhole actuator 1 except the laser perforator 13. The laser perforator 13 requires a significant amount of power and requires a separate perforating high-voltage power supply. The perforating high-voltage power supply is connected to the laser perforator 13 via a cable to provide high-voltage power to the laser perforator 13.

[0037] In one embodiment, Figure 2 As shown, the laser perforator 13 includes a pressure-resistant cylinder 15 with a cavity inside for mounting a laser probe 16. One side of the outer wall of the pressure-resistant cylinder 15 is curved, with the curvature matching that of the casing wall. When the pusher 12 pushes the laser perforator 13 against the casing wall, the side of the pressure-resistant cylinder 15 facing the casing wall contacts and abuts against it, facilitating perforation. The laser probe 16 receives electrical energy from a high-voltage perforation power supply via a high-voltage probe 17.

[0038] In the push-to-pull laser perforating device described in this embodiment, the pressure-resistant cylinder 15 has strong pressure resistance, effectively protecting the laser probe 16 from the pressure of the high-pressure mud 32 in the wellbore. The sidewalls of the pressure-resistant cylinder 15 are curved to match the casing wall, ensuring a tight fit between the cylinder 15 and the casing after the push-to-pull operation, thereby ensuring high perforation quality. In this embodiment, the laser transmitter adopts a split structure, with the power supply and control components located on the surface and the laser probe housed within the pressure-resistant cylinder 15, thus reducing the space occupied underground.

[0039] In one embodiment, Figure 2 As shown, the outer wall of the pressure-resistant tube 15 is provided with a perforation window pin 18, located on the curved surface of the pressure-resistant tube 15 facing the casing wall. The laser emitting probe 16 emits a single-wavelength, intense laser beam. The perforation window pin 18 confines the laser beam emitted by the laser emitting probe 16, concentrating the energy and minimizing energy loss. It also protects the laser emitting probe 16.

[0040] In the push-to-pull laser perforating device described in this embodiment, the perforating window pin 18 can confine the laser light emitted by the laser emitting probe 16. Among existing lasers, only a few are suitable for perforating operations. Laser types can be categorized by the working material they produce, such as gas lasers, dye lasers, metal lasers, solid-state lasers, semiconductor lasers, and free electron lasers. However, only a select few are suitable for laser perforating, including DF or HF lasers, free electron lasers (FELs), chemical oxygen iodine lasers (COILs), CO2 lasers, CO lasers, neodymium yttrium aluminum-doped garnet lasers (Nd:YAG), KrF lasers, mid-infrared chemical lasers, and diode lasers. The primary issue hindering the use of a single laser for drilling and perforating is the laser energy level. The design of this embodiment improves laser perforating efficiency, makes the laser size suitable, and thus expands the range of laser applications.

[0041] In a preferred embodiment, Figure 2 As shown, the compression-resistant cylinder is filled with an elastic filler 19, which covers the laser emitting probe 16. The elastic filler 19 can fix the laser emitting probe 16, preventing damage such as collisions during movement or vibration. Preferably, the elastic filler 19 is a rubber filler.

[0042] In one embodiment, the high voltage probe 17 is covered with a protective sleeve. In this embodiment, the protective sleeve is a ceramic tube. The ceramic tube can protect the high voltage probe 17 from damage and also acts as an insulator.

[0043] In one embodiment, a downhole control unit 14 is provided on the sub, and the downhole control unit 14 receives instructions from the rotation control unit and the pushing control unit, and controls the pusher 12 to complete pushing and rotating actions.

[0044] In this embodiment, if Figure 3 As shown, the downhole control unit 14 is a microcontroller, and the control devices 21 in the surface control unit 2, including the release control unit, rotation control unit, and push control unit, can be computers or other control devices. The downhole control unit 14 has a built-in control program, and controls the pusher 12 and laser perforator 13 in response to instructions from the surface control unit 2.

[0045] In one embodiment, the depth measuring device 11 is a natural gamma ray logging tool.

[0046] During the process of lowering the downhole implement 1 into the well, the length of the cable lowered by the perforating winch can be used to determine the approximate depth. Due to the large downhole depth and complex downhole structure, the cable may bend or have other errors, so a depth measurement device 11 is required for calibration. The downhole depth is determined by detecting the radioactivity in the well using a natural gamma logger.

[0047] During the use of the push-and-pull laser perforating device described in this embodiment, the downhole actuator 1 is first lowered into the well using a cable winch. The depth is then calibrated based on the gamma curve measured by the natural gamma ray sub. The surface lowering control unit confirms the perforation location, and the cable is lowered. The surface push-and-pull unit issues a push command. Upon receiving the command, the downhole control unit 14 sends a power request signal to the surface. The surface operator activates the control unit in response to the power request signal, which activates the pusher 12. The pusher 12 pushes the laser perforator 13 against the casing wall. Once the laser perforator 13 is in close contact with the casing wall, the high-voltage perforating power supply is activated at the surface. The power supply voltage is set based on the lithology to ensure the perforation depth. After perforation is complete, the surface push-and-pull unit issues a retraction command, disengaging the pusher 12 from the casing wall. The laser perforator 13 is then rotated as needed, and perforation is resumed after the rotation angle is determined.

[0048] Although preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they become aware of the basic inventive concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and / or modifications that fall within the scope of the present invention, and changes and / or modifications made in accordance with the embodiments of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A push-type laser perforating device, characterized in that: include: Downhole execution part (1), including a short section, wherein the short section is provided with a depth measuring device (11) for measuring the downhole depth; A pusher (12) connected to the side wall of the short section body is configured to be able to be extended and to push the end portion against the position of the casing wall. A laser perforator (13) connected to the end of the pusher (12), the laser perforator (13) performs perforation operation by laser; the laser perforator (13) includes a pressure-resistant tube (15), the outer wall of the pressure-resistant tube (15) is an arc-shaped tube that matches the casing wall; a laser emitting probe (16) is provided in the pressure-resistant tube (15); and A surface control part (2), the surface control part (2) is connected to the downhole execution part (1) via a cable of a perforating winch, and controls the downhole execution part (1) to be lowered to a predetermined position, rotated at an angle, and perform perforating operations; and provides electrical energy to the downhole execution part (1); The surface control part (2) includes a control device (21), and the control device (21) includes: a lowering control unit, the lowering control unit controls the perforating winch to lower the downhole execution part (1) to a predetermined position through a cable; a rotation control unit, the rotation control unit controls the pusher (12) to rotate; and a pushing control unit, the pushing control unit controls the pusher (12) to push the laser perforator (13) against the casing wall; The ground control part (2) further includes a power supply device (22), and the power supply device (22) includes: a system power supply, the system power supply provides power to the lowering control unit, the rotation control unit and the pushing control unit; a control unit, the control unit provides power to the pushing device (12) and the depth measuring device (11) through a cable; a perforating high-voltage power supply, the perforating high-voltage power supply provides power to the laser perforator (13) through a cable; The laser emission probe (16) receives the electric energy provided by the perforation high-voltage power supply through a high-voltage probe (17); the outer side of the high-voltage probe (17) is covered with a ceramic tube; The short joint is provided with a downhole control unit (14), which receives instructions from the rotation control unit and the pushing control unit, and controls the pushing device (12) to complete pushing and rotating actions.

2. The push-type laser perforating device according to claim 1, characterized in that: A perforation window needle (18) is provided on the wall of the pressure-resistant cylinder (15), and the perforation window needle (18) constrains the laser beam emitted by the laser emission probe (16).

3. The push-type laser perforating device according to claim 2, characterized in that: The pressure-resistant cylinder is filled with an elastic filling piece (19), and the elastic filling piece (19) is wrapped around the outside of the laser emitting probe (16).

4. The push-type laser perforating device according to claim 3, characterized in that: The elastic filling piece (19) is a rubber filling body.

5. The push-type laser perforating device according to claim 4, characterized in that: The depth measuring device (11) is a natural gamma ray logging instrument.

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