Laser perforation well completion system and method for oil and gas well

Abstract

The invention discloses an oil and gas well laser perforation completion system and an oil and gas well laser perforation completion method. The laser perforation completion system comprises a carrying system, a laser perforation system and a laser perforation system, the traction mechanism is arranged on the carrying system; the laser perforating equipment moves up and down in the length direction of the oil-string casing and comprises a center rod, a positioning locking mechanism and a laser perforating mechanism, the positioning locking mechanism and the laser perforating mechanism are arranged on the center rod, and the top of the center rod is connected with the traction mechanism so that the laser perforating equipment can descend to the designated perforating position of the oil-string casing; the positioning and locking mechanism is locked with the inner wall of the oil-string casing, so that the laser perforation mechanism stably cuts the oil-string casing; by means of the system, high efficiency, precision and low damage of ocean oil-string casing perforating operation are achieved, and the system adapts to the technical development trend and economic benefit requirements of deep sea oil and gas exploitation equipment.

Description

Technical Field

[0001] The present application relates to the technical field of perforating equipment, and in particular to a laser perforating completion system and method for oil and gas wells. Background Art

[0002] Well completion is the process of connecting the wellbore to the oil and gas reservoir, and perforation completion is currently the most prevalent method. Existing techniques for perforating oil-casing completion primarily use shaped charges to penetrate the casing, cement sheath, and portions of the pay zone, creating a channel for oil and gas flow. However, this process faces technical bottlenecks, such as reservoir damage from positive-pressure perforation and high limitations from negative-pressure perforation. This makes it difficult to meet the technical requirements of deepwater oil and gas production for efficient operation, precise positioning, and minimal damage and debris-free perforation. Summary of the Invention

[0003] In view of this, the purpose of this application is to propose a laser perforation completion system and method for oil and gas wells to solve the problems of low operating efficiency, insufficient positioning accuracy, and damage to casing and formation structures in the existing technology, and to achieve high efficiency, precision and low damage of marine oil layer casing perforation operations to adapt to the technological development trend and economic benefit requirements of deep-sea oil and gas production equipment.

[0004] Based on the above objectives, the present application provides an oil and gas well laser perforation completion system, comprising:

[0005] delivery system,

[0006] a traction mechanism, provided on the carrying system;

[0007] The laser perforating equipment moves up and down along the length direction of the oil layer casing, and includes a center rod and a positioning and locking mechanism and a laser perforating mechanism arranged on the center rod. The top of the center rod is connected to the traction mechanism so that the perforating system is lowered to the specified perforating position of the oil layer casing. The positioning and locking mechanism is locked with the inner wall of the oil layer casing so that the laser perforating mechanism can stably cut the oil and gas well laser perforating completion system.

[0008] Optionally, the laser perforating mechanism includes a guide and a laser cutting head, the guide is rotatably connected to the bottom of the center rod and performs horizontal rotation of 0°-360° along the central axis of the center rod, a first installation space is provided on the guide, the laser cutting head is rotatably set in the first installation space, and performs a pitch swing of 0°-180° relative to the guide.

[0009] Optionally, a first mounting cavity is provided in the center rod, and the inner wall of the bottom end thereof is bent toward the center of the cavity to form an annular slide rail portion, and the cross-section of the slide rail portion is a U-shaped structure. The outer peripheral surface of the top end of the guide is provided with an annular slide bar portion that cooperates with the slide rail portion, and the outer side wall of the slide bar portion is provided with a flange structure that adapts to the U-shaped groove of the slide rail portion to form a radially limited and circumferentially slidable connection. A first driving mechanism is installed in the first mounting cavity, and the first driving mechanism is connected to the slide bar portion to drive the slide bar portion to rotate horizontally relative to the slide rail portion.

[0010] Optionally, a second mounting cavity is formed inside the guide, and a second drive mechanism is arranged in the second mounting cavity. The second drive mechanism includes a second drive motor and a second drive wheel that is transmission-connected to the power output end of the second drive motor. A first rotating shaft is fixed on the laser cutting head, and the first rotating shaft passes through the first mounting space of the guide and extends to the inside of the second mounting cavity. A first drive wheel is provided at the end of the first rotating shaft, and the second drive wheel is transmission-connected to the first drive wheel through a transmission chain mechanism, so that the laser cutting head can pitch and swing relative to the guide.

[0011] Optionally, the positioning and locking mechanism includes at least two groups of support legs and support feet arranged at the ends of the support legs, a mounting platform is provided on the center rod, a third driving mechanism is provided on the mounting platform, and the third driving mechanism is connected to the support legs to drive the support legs to rotate until the end faces of the support feet abut against the inner wall of the underwater oil casing.

[0012] Optionally, the third driving mechanism includes a third driving motor, a first bevel gear and a second bevel gear, and a third mounting cavity and a slot are formed inside the mounting platform. The third driving motor is fixed on the mounting platform, and its output shaft extends into the third mounting cavity and is fixedly connected to the first bevel gear. A second rotating shaft is fixed to one end of the supporting leg away from the supporting foot, and the second rotating shaft passes through the slot and extends into the third mounting cavity and is fixedly connected to the second bevel gear, and the first bevel gear and the second bevel gear are meshed with each other.

[0013] Optionally, the front end portion of the laser cutting head is respectively formed with a through air outlet and a laser hole along the axial direction, and the laser hole is optically connected with the output end of the laser emitter, so as to enable the high-energy laser beam emitted by the laser emitter to penetrate along the axial direction of the laser hole and perform laser cutting on the part to be cut of the oil layer casing; the air outlet is fluidly connected with the high-pressure gas output end of the air compressor, so as to enable the high-pressure inert gas ejected by the air compressor to pass through the air outlet, discharge the water in the laser cutting area to form a local dry cutting environment, and perform cutting in a local dry method.

[0014] Optionally, a transmission mechanism is further included, comprising a flexible housing, an optical fiber, a high-pressure gas pipeline, and a power control harness. The flexible housing is externally covered by the optical fiber, the high-pressure gas pipeline, and the power control harness. The optical fiber optically connects the laser hole and the laser emitter to achieve transmission of laser energy; the high-pressure gas pipeline fluidically connects the air outlet and the air compressor to achieve delivery of high-pressure inert gas; the power control harness electrically connects the control system and the hole-opening device to achieve transmission of control signals and power supply. The transmission mechanism is modularly designed for easy assembly and disassembly and maintenance. The flexible housing is wear-resistant, high-temperature-resistant, and corrosion-resistant, effectively protecting the internal optical fiber, high-pressure gas pipeline, and power control harness, ensuring stable transmission of laser energy, high-pressure gas, and control signals in the complex downhole environment of the oil layer casing.

[0015] Optionally, a focusing mirror and a protective mirror are provided in the laser hole, and the protective mirror is provided on the outside of the focusing mirror.

[0016] Based on the same inventive concept, the present application also discloses a laser perforation completion method for an oil and gas well, comprising:

[0017] Place the laser perforating device from the carrier system into the oil layer casing, and release the traction rope of the traction mechanism. Under the action of the gravity of the laser perforating device and the traction force of the traction rope, the laser perforating device sinks to the predetermined perforating position of the oil layer casing;

[0018] The laser perforating mechanism performs laser cutting and perforating operations on predetermined perforating positions of the oil layer casing through the pitching, swinging and radial feeding of the laser cutting head.

[0019] The laser perforating mechanism cuts and perforates the designated perforating positions of the oil layer casing.

[0020] As can be seen from the foregoing, the present application provides an oil and gas well laser perforation completion system comprising a carrier system, a traction mechanism, and a laser perforating device. The traction mechanism can quickly lower the laser perforating device to a designated drilling position in the oil layer casing, and the positioning and locking mechanism quickly locks the laser perforating device, allowing the laser perforating device to quickly cut the oil layer casing. This overall improves the efficiency of drilling holes in the oil layer casing and meets the needs of efficient offshore oil production operations. In addition, the traction mechanism precisely controls the depth of the center rod's descent to achieve high-precision positioning of the designated drilling position in the oil layer casing, thereby effectively improving the drilling accuracy of the oil layer casing.

[0021] The present invention relates to the technical field of petroleum engineering, and specifically discloses a perforating completion system for oil layer casing based on laser perforation. In the operation of oil layer casing, the damage problem of traditional perforation technology to the casing and formation structure has become a technical bottleneck in the industry. Compared with the existing perforating completion technology, the laser perforation equipment of the present invention uses a high-energy density laser beam to perform non-contact cutting operations on the cemented casing, and utilizes the instantaneous thermal effect of the laser beam to rapidly vaporize materials, effectively avoiding the impact load generated by mechanical stress on the casing structure, and significantly reducing the damage risks such as casing deformation and rupture; at the same time, the system integrates a high-precision motion control module and an inertial navigation device, and compensates for the shaking and displacement errors during the operation in real time through closed-loop feedback control technology, thereby reducing the disturbance to the formation structure and realizing the effective protection of the geological structure of the reservoir. In addition, relying on the high directivity and energy concentration characteristics of the laser beam, the system can achieve millimeter-level drilling accuracy, and greatly improve the perforation efficiency through an automated operation process, effectively reducing the labor and equipment input costs compared with the traditional process. The present invention provides a cementing perforation solution with high precision, high efficiency and low damage characteristics for offshore oil exploitation, and can fully meet the dual requirements of deep-sea oil and gas resource development for technological innovation and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the present application or related technologies, the following will briefly introduce the drawings required for use in the embodiments or related technology descriptions. Obviously, the drawings in the following descriptions are only the embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0023] Figure 1 It is a schematic structural diagram showing the carrier system and the traction mechanism in the embodiment of the present application;

[0024] Figure 2 It is a cross-sectional view showing the guide and the central rod in the embodiment of the present application;

[0025] Figure 3 It is a schematic structural diagram showing the laser cutting head in the embodiment of the present application;

[0026] Figure 4 It is a schematic structural diagram showing the transmission mechanism in the embodiment of the present application;

[0027] Figure 5 It is a schematic structural diagram showing the third driving mechanism in the embodiment of the present application.

[0028] Reference numerals: 1, carrier system; 11, control system; 2, traction mechanism; 21, traction rope; 22, rope winder; 3, hole-opening device; 31, central rod; 311, first installation cavity; 3111, first driving mechanism; 312, slide rail part; 3121, internal gear ring; 3122, gear; 3123, sealing ring; 315, mounting table; 3151, third installation cavity; 3152, notch; 32, positioning and locking mechanism; 321, support leg; 322, support foot; 3211, installation groove; 3212, second rotating shaft; 33, laser perforation mechanism; 331, guide; 3311, first installation space; 3312, slide bar part; 3313, second installation cavity; 332, laser cutting head; 3321, first rotating shaft; 3322, first driving wheel; 3323, air outlet; 3324, laser hole; 333, second driving mechanism; 3331, second driving motor; 3332, second driving wheel; 4, third driving mechanism; 41, third driving motor; 42, first bevel gear; 43, second bevel gear; 5, transmission mechanism; 51, flexible housing; 52, optical fiber; 53, high-pressure gas pipeline; 54, power control wire harness; 6, focusing lens; 61, protective lens. Detailed implementation manners

[0029] In order to make the objectives, technical solutions and advantages of the present application clearer and more understandable, the present application will be further described in detail below with reference to specific embodiments and the accompanying drawings.

[0030] It should be noted that unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should have the ordinary meanings understood by those of ordinary skill in the field to which the present application belongs. The "first", "second" and similar terms used in the embodiments of the present application do not indicate any order, quantity or importance, but are only used to distinguish different components. The terms such as "include" or "comprise" mean that the elements or objects appearing before the term cover the elements or objects listed after the term and their equivalents, without excluding other elements or objects. The terms such as "connect" or "be connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms such as "upper", "lower", "left" and "right" are only used to represent relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0031] In the context of the exploration and development of deep-sea oil and gas resources expanding towards deep water, deep layers and complex geological conditions, the oil production casing project, as the core technology to ensure the safe and stable operation of oil and gas wells throughout their life cycle, the integrity of its technical system directly affects the oil and gas production efficiency and engineering safety. As the core pressure-bearing component of the wellbore structure, the oil casing realizes the functions of mechanical support for the surrounding rock of the wellbore, isolation of formation fluids and protection of downhole strings through the composite sealing system formed by it and the cement sheath. Among them, the completion technology, as the key technical link for constructing the fluid channel between the oil and gas reservoir and the wellbore, by forming a precisely controllable flow interface in the casing-cement sheath-formation complex, establishing an oil and gas seepage channel and eliminating the pollution in the near-wellbore area, plays a decisive role in releasing the productivity of the reservoir and improving the oil and gas recovery rate.

[0032] The traditional perforating completion method using shaped charges is a widely used completion method at present. It uses the impact force generated by the explosion of shaped charges under high pressure to penetrate the casing and formation, forming a flow channel for oil and gas. However, the perforating completion method using shaped charges has some disadvantages. Firstly, it causes formation damage. When the high-temperature and high-pressure jet generated by the explosion of shaped charges penetrates the formation, the rock around the hole will undergo plastic deformation, forming a compaction zone. This will lead to a decrease in formation permeability, increase the resistance of oil and gas flow, and affect the productivity of oil and gas wells. During the perforating process, particulate debris such as casing materials, cement, rock fragments, and shaped charge fragments will be generated. These fragments will block the perforation channels, reduce the effective flow area of the channels, and decrease the inflow and outflow capabilities of oil and gas. When perforating in deviated wells and inclined wells, due to the presence of an annulus filled with fluid, i.e., the "fluid gap", between the outer wall of the perforating gun and the inner wall of the target casing, conventional shaped charges are difficult to overcome this problem, resulting in inconsistent perforation hole sizes. This will cause problems such as small hole erosion and slotting, insufficient hole utilization, low efficiency of well stimulation, and slow down the rate of pressure rise to the expected treatment pressure. Limited by the structure of the perforating gun and the arrangement of shaped charges, it is sometimes difficult to achieve high shot density and ideal perforating phase, thus affecting the productivity improvement and development effect of oil and gas wells. For example, for some formations that require high shot density perforation to increase the flow area of oil and gas, shaped charges may not meet the requirements; inappropriate perforating phase may not effectively connect the oil and gas channels in the formation. Shaped charges use explosives for detonation, and there is a certain explosion risk during transportation, storage, and use. It is necessary to strictly abide by relevant safety regulations and operating procedures to prevent accidents. The size of the perforating gun is limited by the inner diameter of the tubing, with small power and limited charge loading, affecting the perforating penetration; at the same time, limited by equipment such as the wellhead blowout preventer, the length of the perforating gun cannot be too long. For thick oil and gas layers, multiple runs of the gun may be required, increasing the operation time, workload, and cost. In addition, perforating completion also causes significant pollution to the pay zone during the cementing process, and the connectivity with the formation is relatively poor. Especially for fractured pay zones, directional perforation is usually required to better connect the formation fractures.

[0033] In summary, the existing perforating completion method using shaped charges is difficult to achieve an ideal balance in terms of drilling accuracy, casing and formation protection, operation efficiency, cost control, and adaptation to complex subsea environments. Therefore, there is an urgent need for a new type of oil layer casing perforating completion method that can overcome the above deficiencies of the existing technology and meet the growing technical requirements and economic benefits of offshore oil exploitation.

[0034] To solve the above problems, the present application provides an oil and gas well laser perforating completion equipment and method.

[0035] The following will be combined with the attached Figures 1-5 to detail the embodiments of the present application.

[0036] As Figure 1 shown, an oil and gas well laser perforation completion system includes:

[0037] A carrier system 1,

[0038] A traction mechanism 2, which is arranged on the carrier system 1;

[0039] A laser perforation device 3, which moves up and down along the length direction of the oil layer casing. It includes a central rod 31, a positioning and locking mechanism 32 and a laser perforation mechanism 33 arranged on the central rod 31. The top of the central rod 31 is connected to the traction mechanism 2 so that the perforation system 3 descends to the designated perforation position of the oil layer casing. The positioning and locking mechanism 32 is locked with the inner wall of the oil layer casing so that the laser perforation mechanism 33 stably cuts the oil layer casing.

[0040] Specifically, the carrier system 1 is an offshore mobile vessel. The traction mechanism 2 is arranged on the carrier system 1 and includes a rope reel 22 and a traction rope 21. The rope reel 22 is installed and fixed inside the carrier system 1. The top of the central rod 31 is provided with a hanging ring structure. One end of the traction rope 21 is wound and connected to the reel of the rope reel 22, and the other end is connected to the hanging ring at the top of the central rod 31. By operating the rope reel 22 to wind and unwind the reel, the up and down control of the central rod 31 and the connected opening device 3 along the oil layer casing direction is realized, so as to accurately adjust the operation position of the opening device 3 on the oil layer casing. The rope reel 22 is also equipped with a complete braking system, including two methods of electromagnetic braking and mechanical braking. Under normal operating conditions, the electromagnetic braking unit can realize the rapid start-stop and smooth displacement of the opening device 3. The rotation speed of the reel is accurately controlled by electromagnetic force to ensure the stability and positioning accuracy of the opening device 3 during the moving process. When an emergency occurs, the mechanical braking unit serves as a redundant safety guarantee and can quickly apply a strong braking force to lock the rotation of the reel, prevent the traction rope 21 from getting out of control, and ensure the safety of the laser perforation device 3 and the entire operation system. The traction rope 21 is made of a high-strength and corrosion-resistant synthetic fiber rope, such as an aramid fiber rope. This aramid fiber rope has the characteristics of light weight, high tensile strength, good wear resistance and resistance to reservoir fluid corrosion, and can meet the long-term operation requirements under the deep-sea high-pressure, high-salt and complex fluid environment. At the same time, multiple high-strength steel wires are axially embedded inside the traction rope 21 to form a composite reinforcement structure, further improving the overall tensile strength and fatigue resistance of the traction rope 21, effectively preventing the rope from breaking under frequent winding and unwinding and harsh working conditions, and ensuring the reliability and operation continuity of the traction system.

[0041] The central rod 31, which is the core support component of the hole-opening device 3, is preferably made of high-strength alloy steel with a yield strength of not less than 1200 MPa to ensure that it can smoothly penetrate complex geological layers and accurately reach the preset operating depth under the action of its own gravity and the axial traction force provided by the traction mechanism 2. A composite anti-corrosion coating system is formed on the outer surface of the central rod 31 through thermal spraying or chemical vapor deposition processes.

[0042] In addition, a high-definition underwater camera device meeting the IP68 protection level is integrated at the lower end of the central rod 31. Together with an adjustable LED fill light system, it can collect real-time geological feature images during the descent of the hole-opening device 3, as well as key data such as the hole position accuracy and cutting state during the hole-opening operation of the oil layer casing. The collected video signals are transmitted in real time to the sea surface control platform through the optical fiber transmission channel built inside the central rod 31 at a resolution of not less than 1080P, providing an accurate basis for operation monitoring and parameter adjustment for the operator.

[0043] In this embodiment, the traction mechanism 2 can quickly lower the hole-opening device 3 to the designated hole-opening position of the oil layer casing, and the positioning and locking mechanism 32 quickly locks the hole-opening device 3, so that the laser perforation mechanism 33 can quickly cut the oil layer casing, improving the hole-opening operation efficiency of the oil layer casing and meeting the requirements of efficient operation in offshore oil exploitation. In addition, by precisely controlling the descent depth of the central rod 31 through the traction mechanism 2, high-precision positioning of the designated drilling position of the oil layer casing is achieved, thereby effectively improving the hole-opening accuracy of the oil layer casing. The laser perforation mechanism 33 cuts the oil layer casing, with less impact force on the structure of the oil layer casing, thus reducing damage to the casing. At the same time, the entire system has good stability during operation, reducing damage to the formation structure caused by reasons such as shaking and displacement, thereby better protecting the formation structure. The laser perforation and well completion in this application have high drilling accuracy and high operation efficiency, can better protect the casing and the formation, save labor costs and material costs, and thus meet the growing technical and economic requirements of offshore oil exploitation.

[0044] In some embodiments, such as Figure 1 and Figure 2 shown, the laser perforation mechanism 33 includes a guide 331 and a laser cutting head 332. The guide 331 is rotatably connected to the bottom of the central rod 31 and rotates horizontally by 0° - 360° along the central axis of the central rod 31. A first installation space 3311 is provided on the guide 331, and the laser cutting head 332 is rotatably arranged in the first installation space 3311 and swings up and down by 0° - 180° relative to the guide 331.

[0045] Specifically, the first installation space 3311 is recessed from the housing of the guide towards the central rod 31. The laser cutting head 332 performs a pitching swing of 0° - 180° relative to the guide 331 within the first installation space 3311. When the laser cutting head 332 cuts on the inner wall of the irregular oil layer casing, the angle of the laser cutting head 332 can be adjusted to keep the laser always perpendicular to the cutting surface, ensuring the accuracy of the cutting path.

[0046] In this embodiment, the guide 331 has a high-precision horizontal rotation function, and the laser cutting head 332 can accurately perform a pitching swing. The two work together, enabling the laser cutting head 332 to flexibly align the to-be-cut part of the oil casing from multiple angles, thus being able to well adapt to the complex and diverse cutting conditions on the inner wall of the oil casing.

[0047] In some embodiments, as Figure 2 shown, a first installation cavity 311 is provided inside the central rod 31. The inner wall of its bottom end bends towards the center of the cavity to form an annular slide rail part 312. The cross-section of this slide rail part is in a U-shaped structure. An annular slide bar part 3312 that matches the slide rail part 312 is provided on the outer peripheral surface of the top end of the guide 331. A flange structure adapted to the U-shaped groove of the slide rail part 312 is provided on the outer side wall of the slide bar part 3312, forming a connection fit with radial limitation and circumferential slidability. A first driving mechanism 3111 is installed in the first installation cavity 311, and the first driving mechanism 3111 is connected to the slide bar part 3312 to drive the slide bar part 3312 to horizontally rotate relative to the slide rail part 312.

[0048] Specifically, the central column is cylindrical, the rail portion 312 is U-shaped, and the slider portion 3312 is an inverted U-shaped structure. The rail portion 312 and the slider portion 3312 cooperate to form a stable and precise sliding guide structure. This ensures that when the first drive mechanism 3111 drives the slider portion 3312 to rotate horizontally relative to the rail portion 312, the slider portion 3312 rotates smoothly along a predetermined circular path, effectively preventing any shaking or deviation that may occur during rotation. A sealing ring 3123 is provided between the rail portion 312 and the slider portion 3312. This sealing ring 3123 is a bearing sealing ring 3123. The bearing sealing ring 3123 prevents reservoir fluid from invading the first mounting cavity 311, protecting the internal mechanical structure from erosion by the reservoir fluid, thereby extending the equipment's underwater operating time and reducing maintenance costs and the incidence of equipment failures. The first drive mechanism 3111 is a drive motor mounted on a sidewall of the first mounting cavity 311. The first drive mechanism 3111 has an output shaft connected to a gear 3122. The slide portion 3312 is connected to an inner gear ring 3121. The gear 3122 meshes with the inner gear ring 3121, thereby driving the slide portion 3312 to rotate horizontally relative to the rail portion 312. Alternatively, the first drive mechanism 3111 may be directly connected to the slide portion 3312, thereby directly driving the slide portion 3312 to rotate horizontally relative to the rail portion 312.

[0049] In this embodiment, the first drive mechanism 3111 is mounted within the first mounting cavity 311, providing good protection and making it less susceptible to interference and damage from external environmental factors. This extends the service life of the first drive mechanism 3111 and improves the reliability and stability of the entire system. The slide rail portion 312 is slidably connected to the slide bar portion 3312, allowing the guide 331 to move along a specific path within the center rod 31. This improves the stability and accuracy of the guide 331 during movement, reduces shaking and offset, and thus achieves precise guidance.

[0050] In some embodiments, as Figure 2 As shown, a second mounting cavity 3313 is formed inside the guide 331, and a second driving mechanism 333 is arranged in the second mounting cavity 3313. The second driving mechanism 333 includes a second driving motor 3331 and a second driving wheel 3332 that is transmission-connected to the power output end of the second driving motor 3331. A first rotating shaft 3321 is fixed on the laser cutting head 332. The first rotating shaft 3321 passes through the first mounting space 3311 of the guide 311 and extends to the inside of the second mounting cavity 3313. A first driving wheel 3322 is provided at the end of the first rotating shaft 3321. The second driving wheel 3332 and the first driving wheel 3322 are transmission-connected through a transmission chain mechanism, so that the laser cutting head 332 can pitch and swing relative to the guide 331.

[0051] Specifically, the second driving mechanism 333 is installed on the inner wall of the second installation cavity 3313 of the guide 331. The second driving mechanism 333 can be a servo motor, which has high-precision speed control and torque control capabilities. It can accurately control the pitching angle of the laser cutting head 332 according to the system requirements, and has a fast response speed, which can improve the working efficiency of the entire system. A speed reduction device, such as a speed reducer, can be added between the second driving mechanism 333 and the second driving wheel 3332 to reduce the output speed of the second driving mechanism 333 and increase the torque at the same time, making the pitching swing of the laser cutting head 332 smoother and more accurate. An angle sensor can be installed on the first rotating shaft 3321 of the laser cutting head 332 to real-time monitor the pitching angle of the laser cutting head 332 and feedback the angle information to the control system 11. The control system 11 makes real-time adjustments to the second driving motor 3331 according to the feedback information, thereby improving the control accuracy of the pitching angle of the laser cutting head 332.

[0052] In this embodiment, the second driving mechanism 333 drives the laser cutting head 332 to perform pitching swing, so that the laser cutting head 332 can flexibly change the angle within a certain range, improving the versatility and adaptability of the laser cutting head 332. Adopting the transmission method of the second driving wheel 3332, the first driving wheel 3322 and the transmission hinge to drive the guide 331 can enable the guide 331 to achieve relatively smooth pitching swing. The transmission hinge can buffer and absorb the impact force during the transmission process to a certain extent, reduce vibration and noise, and improve the smoothness and stability of the movement of the laser cutting head 332.

[0053] In some embodiments, as Figure 2 , Figure 3 and Figure 4 shown, through holes 3323 and laser holes 3324 are respectively formed axially at the front end of the laser cutting head 332. The laser hole 3324 is optically communicated with the output end of the laser emitter, and is used to make the high-energy laser beam emitted by the laser emitter penetrate along the axis direction of the laser hole 3324 and perform laser cutting on the part to be cut of the oil layer casing; the through hole 3323 is fluidly communicated with the high-pressure gas output end of the air compressor, and is used to make the high-pressure inert gas ejected by the air compressor pass through the through hole 3323 and eject, so as to discharge the water body in the laser cutting area to form a local dry cutting environment for cutting by local dry method.

[0054] In addition, a focusing lens 6 and a protective lens 61 are provided in the laser hole 3324, and the protective lens 61 is provided outside the focusing lens 6.

[0055] The oil casing opening system further includes a transmission mechanism 5. The transmission mechanism 5 includes a flexible outer shell 51, an optical fiber 52, a high-pressure gas pipeline 53, and a power control wire harness 54. The flexible outer shell 51 covers the optical fiber 52, the high-pressure gas pipeline 53, and the power control wire harness 54. The optical fiber 52 is optically connected to the laser hole 3324 and the laser emitter for transmitting laser energy. The high-pressure gas pipeline 53 is fluidly connected to the air outlet hole 3323 and the air compressor for transporting high-pressure inert gas. The power control wire harness 54 is electrically connected to the control system 11 and the opening device 3 for transmitting control signals and power supplies.

[0056] Specifically, the laser hole 3324 penetrates through the central position of the laser cutting head 332. The air outlet hole 3323 is in the same direction as the laser hole 3324. A plurality of air outlet holes 3323 are provided and evenly surround the outside of the laser hole 3324. One end of the high-pressure gas pipeline 53 close to the air outlet hole 3323 is divided into a plurality of independent branch pipelines, and each branch pipeline is connected to one air outlet hole 3323. The air outlet hole 3323 can be set at a certain inclination angle (30° - 60°) relative to the laser hole 3324, so as to form a relatively stable and size-adjustable water-free area directly below the laser cutting head 332, so that the laser can act directly on the oil casing without being interfered by the reservoir fluid. The air outlet hole 3323 is connected to an air compressor, which is placed on the carrier system 1 and can generate a water pressure not less than the rated working water depth and has a certain redundant pressure, so as to discharge the reservoir fluid on the optical path and aerosol particles that may scatter or refract the laser. In addition, the inner wall of the metal oil casing melts instantaneously under the action of the laser to form a molten metal pool, and the cement vaporizes instantaneously under the action of the laser energy. The gas output by the air compressor can blow away the molten metal pool and the re-solidified cement particles to prevent the above impurities from affecting the opening. The laser hole 3324 is connected to the laser emitter through the optical fiber 52. The laser emitter is set on the carrier system 1 and is a fiber laser with a rated power of not less than 6000W to ensure that the generated laser can complete the cutting work on the oil layer casing. The control system 11 is provided on the carrier system 1 and is connected to the opening device 3 through the power control wire harness 54 to control the operation of devices such as the first driving mechanism 3111 and the second driving mechanism 333. The control system 11 is also connected to the air compressor and the laser emitter to control the operation of the air compressor and the laser emitter.

[0057] In addition, the flexible outer shell 51 is made of a high-strength and corrosion-resistant composite material, such as carbon fiber reinforced plastic (CFRP). This material not only has good flexibility but also can effectively resist the corrosion of reservoir fluids and the erosion of underwater organisms, thus extending the service life of the transmission mechanism 5. Sensors can be installed on the optical fiber 52, high-pressure gas pipeline 53, and power control wire harness 54 to monitor the status of the lines in real time, such as the optical loss of the optical fiber 52, the pressure of the high-pressure gas pipeline 53, and the current of the power control wire harness 54. Once an abnormal situation occurs, the sensor transmits the signal to the control system 11 for timely warning and processing.

[0058] In this embodiment, the laser emitted by the laser emitter directly acts on the oil layer casing through the laser hole 3324. The high-energy characteristic of the laser enables it to quickly cut the oil layer casing. Laser cutting has high precision, a narrow cut, and a small heat-affected zone, which can effectively reduce the damage to the surrounding structure of the casing. The focusing mirror 6 in the laser hole 3324 can focus the laser beam onto a very small point, further increasing the energy density of the laser and enhancing the cutting ability of the laser, so that efficient cutting can be achieved on oil casings of different thicknesses and materials. The protective mirror 61 provided in the laser hole 3324 is located outside the focusing mirror 6 and can effectively block impurities such as splashes, dust, and water vapor generated during the cutting process, preventing these impurities from adhering to the focusing mirror 6 and avoiding damage or contamination of the focusing mirror 6, which affects the focusing effect and transmission quality of the laser, helps to extend the service life of the focusing mirror 6, and reduces the equipment maintenance cost. The high-pressure inert gas ejected by the air compressor discharges water and aerosol particles that scatter or refract the laser through the air outlet hole 3323, creating a clean and water-free environment in the laser cutting area, avoiding the absorption and scattering of the laser transmission by water and impurities, reducing the loss of laser energy, so that the laser can reach the surface of the oil casing with higher energy, ensuring the smooth progress of the cutting process.

[0059] In some embodiments, as Figure 1 shown, the positioning and locking mechanism 32 includes at least two groups of support legs 321 and support feet 322 provided at the ends of the support legs 321. An installation platform 315 is provided on the central rod 31, and a third driving mechanism 4 is provided on the installation platform 315. The third driving mechanism 4 is connected to the support legs 321 to drive the support legs 321 to rotate until the end face of the support feet 322 abuts against the inner wall of the oil layer casing.

[0060] Optionally, the supporting legs 321 can be set to three groups to form a stable positioning and locking structure, thus ensuring the accuracy and stability of the laser cutting operation. An accommodating groove is provided at one end of the supporting leg 321 away from the mounting table 315. The supporting foot 322 is installed in the accommodating groove through a connecting shaft. When the supporting leg 321 rotates to contact the inner wall of the sleeve, the supporting foot 322 can automatically adjust its own posture according to the actual shape and angle of the inner wall to achieve the best fitting state, thereby improving the stability of the support. The end face of the supporting foot 322 is provided with an anti-slip pad or anti-slip texture, such as serrated or grid-like texture, to increase the friction between the supporting foot 322 and the inner wall of the sleeve, preventing the supporting foot 322 from sliding due to equipment vibration or ocean current impact during the cutting process and ensuring the reliability of the positioning and locking. A pressure sensor can be provided on the end face of the supporting foot 322 to monitor the pressure between the supporting foot 322 and the inner wall of the sleeve. The third driving mechanism 4 is connected to the control system 11. The control system 11 can accurately adjust the rotation of the supporting leg 321 according to the actual situation to ensure that the supporting foot 322 abuts against the inner wall of the sleeve with an appropriate force, avoiding the situation of damaging the sleeve due to excessive pressure or unstable support due to too small pressure.

[0061] In this embodiment, the third driving mechanism 4 drives the supporting leg 321 to rotate so that the supporting foot 322 accurately abuts against the inner wall of the oil layer casing, thereby accurately locking the positioning and locking mechanism 32 at a specific position in the oil layer casing and providing an accurate reference for subsequent operations such as laser cutting.

[0062] In some embodiments, such as Figure 1 and Figure 5 shown, the third driving mechanism 4 includes a third driving motor 41, a first bevel gear 42 and a second bevel gear 43. A third installation cavity 3151 and a notch 3152 are provided on the mounting table 315. The third driving motor 41 is installed on the mounting table 315, and its output shaft extends into the third installation cavity 3151 and is fixedly connected to the first bevel gear 42. One end of the supporting leg 321 away from the supporting foot 322 is provided with a second rotating shaft 3212. The second rotating shaft 3212 passes through the notch 3152 and extends into the third installation cavity 3151 and is fixedly connected to the second bevel gear 43. The first bevel gear 42 meshes with the second bevel gear 43.

[0063] Specifically, the third driving motor 41 is installed on the upper surface of the mounting table 315, and its output shaft passes through a part of the mounting table 315 and extends into the third mounting cavity 3151 to drive the first bevel gear 42 to rotate. The third driving motor 41 can be a servo motor. The servo motor has high-precision position control and speed control capabilities, and can accurately control the rotation angle and speed of the support leg 321 according to the instructions of the control system 11. At the same time, the servo motor also has overload protection and feedback functions, which can monitor the operating state of the motor in real time, improving the reliability and safety of the system. An angle sensor can be installed on the second rotating shaft 3212 to monitor the rotation angle of the support leg 321 in real time. The angle sensor feeds back the monitored angle information to the control system 11, and the control system 11 makes real-time adjustments to the third driving motor 41 according to the feedback information to achieve precise control of the rotation angle of the support leg 321.

[0064] In addition, the third driving motor 41 can also be installed on the periphery of the mounting table 315. The third driving mechanism 4 can be composed of a driving motor, a driving gear connected to the output shaft of the driving motor, and a driven rack corresponding to each support leg 321 one by one. A transmission connection is formed between the driven rack and the support leg assembly through a linkage mechanism; when the driving motor drives the driving gear to rotate, through the transmission cooperation of the driven rack and the linkage mechanism, each group of support legs 321 can be driven to rotate synchronously around the hinge point and open outwards until the end faces of the support feet 321 are in close contact with the inner wall of the oil layer casing, so as to realize the radial positioning and locking of the device in the wellbore.

[0065] In this embodiment, the meshing structure of the first bevel gear 42 and the second bevel gear 43 can change the transmission direction of the output shaft of the third driving motor 41, so as to realize the rotation of the second rotating shaft 3212 within a limited installation space, thereby optimizing the spatial layout of the entire positioning and locking mechanism 32. In addition, the bevel gear transmission has high transmission accuracy and can accurately transmit the power of the motor to the support leg 321, so that the support leg 321 rotates at a predetermined angle and speed. The mounting table 315 is provided with a third mounting cavity 3151 and a notch 3152. The third mounting cavity 3151 and the notch 3152 provide installation positions for the third driving motor 41, the bevel gear 3122, and the second rotating shaft 3212 of the support leg 321, making the entire driving mechanism structure compact, reducing the overall volume of the equipment, and being suitable for use in a limited underwater space environment.

[0066] Based on the same inventive concept, corresponding to any of the above embodiments, the present application also provides a method for laser perforation in oil well cementing, including:

[0067] Lower the laser perforation device 3 from the carrier system 1 into the oil layer casing, release the towing rope 21 of the towing mechanism 2, and under the action of the gravity of the laser perforation device 3 and the traction force of the towing rope 21, the laser perforation device 3 sinks to the predetermined perforation position of the oil layer casing;

[0068] The laser perforation mechanism 33 performs laser cutting and perforation operations on the predetermined perforation position of the oil layer casing through the pitching swing and radial feed of the laser cutting head 332.

[0069] Specifically, before lowering the opening device 3, use equipment such as underwater robots and high-definition cameras to detect the oil layer casing. The high-definition endoscope camera conducts intuitive image acquisition of the inside of the casing. With its ultra-wide-angle field of view and high-resolution imaging ability, it can clearly capture the specific positions and accumulation forms of impurities that may adhere to the inner wall of the casing, such as seabed sediment, microbial aggregates, and petroleum residues. Provide a solid data basis for the fine adjustment of equipment parameters and the reasonable planning of the operation process during subsequent opening operations, and ensure the efficient and safe progress of the opening operations.

[0070] An equipment debugging platform is built on the carrier system 1 to conduct a comprehensive debugging of the laser perforation device 3. In addition to conventional electrical performance tests and mechanical component operation inspections, a simulation cutting test is also carried out on the laser perforation mechanism 33. For example: in a test chamber that simulates the underwater pressure and temperature environment, use sample pipes made of the same or similar materials as the oil layer casing to conduct cutting tests under different parameter combinations. By analyzing indicators such as the cutting quality and the size of the heat-affected zone of the cut samples, determine the best laser parameters and store them in the control system 11 of the laser perforation device 3 for direct calling after being lowered.

[0071] The laser perforation device 3 is equipped with multiple high-precision sensors, including accelerometers, gyroscopes, pressure sensors, etc. The accelerometer and gyroscope monitor the attitude changes of the laser perforation device 3 during the lowering process in real time, and the pressure sensor monitors the reservoir fluid pressure received by the device. The above sensor data is sent to the monitoring center of the carrier system 1 in real time through a wireless transmission module. Once it is detected that the device attitude shows abnormal inclination or abnormal pressure change, the monitoring center immediately issues an instruction to adjust the winding and unwinding speed of the towing rope 21 through the towing mechanism 2 to correct the device attitude and ensure the smooth lowering of the device.

[0072] The positioning and locking mechanism 32 is equipped with a pressure sensor to monitor the contact pressure between the positioning and locking mechanism 32 and the inner wall of the casing in real time. The control system 11 automatically adjusts the positioning and locking mechanism 32 according to these real-time data, so that the positioning and locking mechanism 32 locks the inner wall of the casing with the best force and angle, thereby realizing precise positioning and locking.

[0073] During the cutting process of the laser perforation mechanism 33, a high-speed camera is used to take real-time pictures of the cutting area. Through image analysis technology, the incision condition during the cutting process is monitored in real time. Once problems such as abnormal laser incisions are found, the control system 11 immediately adjusts the cutting parameters to ensure the cutting quality.

[0074] In this embodiment, under the action of the gravity of the hole-opening device 3 and the traction force of the traction rope 21, the hole-opening device 3 sinks to the designated hole-drilling position of the oil layer casing, laying a solid foundation for subsequent precise cutting. The positioning and locking mechanism 32 can firmly fix the hole-opening device 3 on the oil layer casing, effectively resisting the impact force generated by the fluid flow in the reservoir and the vibration of the device itself during the cutting process, providing a stable and reliable support for the smooth operation of the laser perforation mechanism 33, and ensuring the cutting quality. Based on the stable positioning, the laser perforation mechanism 33 cuts the designated hole-drilling position, with less impact on the casing structure, thereby reducing the damage to the casing. At the same time, the operation process of the whole system is stable, reducing the damage to the formation structure caused by reasons such as shaking and displacement, thus better protecting the formation structure. The laser perforation completion method for oil and gas wells in this application has high drilling accuracy and high operation efficiency, can better protect the casing and the formation, saves labor costs and material costs, and thus meets the growing technical requirements and economic benefit requirements of offshore oil exploitation.

[0075] Those of ordinary skill in the art should understand that: the discussion of any of the above embodiments is exemplary only, and is not intended to imply that the scope of the present application (including the claims) is limited to these examples; under the concept of the present application, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the embodiments of the present application as described above, which are not provided in detail for the sake of brevity.

[0076] In addition, for the sake of simplicity of explanation and discussion, and in order not to make the embodiments of the present application difficult to understand, the well-known power / ground connections to integrated circuit chips and other components may or may not be shown in the provided drawings. In addition, the device may be shown in block diagram form to avoid making the embodiments of the present application difficult to understand, and this also takes into account the fact that the details of the implementation of these block diagram devices are highly dependent on the platform on which the embodiments of the present application are to be implemented (that is, these details should be completely within the understanding of those skilled in the art). In the case where specific details (such as circuits) are set forth to describe the exemplary embodiments of the present application, it will be apparent to those skilled in the art that the embodiments of the present application can be implemented without these specific details or with variations of these specific details. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0077] Although the present application has been described in connection with specific embodiments thereof, many alternatives, modifications, and variations of these embodiments will be apparent to those of ordinary skill in the art in light of the foregoing description. For example, other memory architectures may be used with the embodiments discussed.

[0078] Embodiments of the present application are intended to cover all such alternatives, modifications, and variations that fall within the broad scope of the appended claims. Accordingly, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the embodiments of the present application shall be included within the protection scope of the present application.

Claims

1. An oil and gas well laser perforation completion system, characterized in that include: Delivery system (1); A traction mechanism (2) is provided on the transport system (1); The laser perforating device (3) moves up and down along the length direction of the oil layer casing, and comprises a center rod (31) and a positioning locking mechanism (32) and a laser perforating mechanism (33) arranged on the center rod (31). The top of the center rod (31) is connected to the traction mechanism (2) so that the laser perforating device (3) descends to the designated perforating position of the oil layer casing, and the positioning locking mechanism (32) is locked with the inner wall of the oil layer casing so that the laser perforating mechanism (33) can stably cut the oil layer casing.

2. The laser perforation completion system for oil and gas wells according to claim 1, wherein The laser perforating mechanism (33) comprises a guide (331) and a laser cutting head (332); the guide (331) is rotatably connected to the bottom of the center rod (31) and performs horizontal rotation of 0°-360° along the central axis of the center rod (31); a first installation space (3311) is provided on the guide (331); the laser cutting head (332) is rotatably arranged in the first installation space (3311) and performs pitch swing of 0°-180° relative to the guide (331).

3. The laser perforation completion system for oil and gas wells according to claim 2, characterized in that, A first mounting cavity (311) is provided in the center rod (31), and the inner wall of the bottom end thereof is bent toward the center of the cavity to form an annular slide rail portion (312), and the cross section of the slide rail portion is a U-shaped structure. The outer peripheral surface of the top end of the guide (331) is provided with an annular slide bar portion (3312) that matches the slide rail portion (312), and the outer wall of the slide bar portion (3312) is provided with a flange structure that matches the U-shaped groove of the slide rail portion (312), forming a radially limited and circumferentially slidable connection. A first driving mechanism (3111) is installed in the first mounting cavity (311), and the first driving mechanism (3111) is connected to the slide bar portion (3312) to drive the slide bar portion (3312) to rotate horizontally relative to the slide rail portion (312).

4. The laser perforation completion system for oil and gas wells according to claim 3, characterized in that, A second installation cavity (3313) is formed inside the guide (331), and a second driving mechanism (333) is arranged in the second installation cavity (3313). The second driving mechanism (333) includes a second driving motor (3331) and a second driving wheel (3332) connected to the power output end of the second driving motor (3331). A first rotating shaft (3321) is fixed on the laser cutting head (332), and the first rotating shaft (3321) passes through the first installation space (3311) of the guide (331) and extends to the inside of the second installation cavity (3313). A first driving wheel (3322) is provided at the end of the first rotating shaft (3321). The second driving wheel (3332) and the first driving wheel (3322) are connected to each other through a transmission chain mechanism, so that the laser cutting head (332) can pitch and swing relative to the guide (331).

5. The laser perforation completion system for oil and gas wells according to claim 1, characterized in that, The positioning and locking mechanism (32) includes at least two groups of support legs (321) and support feet (322) provided at the ends of the support legs (321). An installation platform (315) is provided on the central rod (31), and a third driving mechanism (4) is provided on the installation platform (315). The third driving mechanism (4) is connected to the support legs (321) to drive the support legs (321) to rotate until the end face of the support feet (322) abuts against the inner wall of the subsea oil casing.

6. The laser perforation completion system for oil and gas wells according to claim 5, characterized in that The third driving mechanism (4) includes a third driving motor (41), a first bevel gear (42) and a second bevel gear (43). A third installation cavity (3151) and a notch (3152) are formed inside the installation platform (315). The third driving motor (41) is fixedly provided on the installation platform (315), and its output shaft extends into the third installation cavity (3151) and is fixedly connected to the first bevel gear (42). One end of the support leg (321) far from the support foot (322) is fixedly provided with a second rotating shaft (3212). The second rotating shaft (3212) passes through the notch (3152) and extends into the third installation cavity (3151) and is fixedly connected to the second bevel gear (43). The first bevel gear (42) meshes with the second bevel gear (43).

7. A laser perforation completion system for oil and gas wells according to claim 1, characterized in that The front end of the laser cutting head (332) is axially formed with a through air hole (3323) and a laser hole (3324). The laser hole (3324) is optically connected to the output end of the laser emitter, and is used to make the high-energy laser beam emitted by the laser emitter penetrate along the axis direction of the laser hole (3324) and perform laser cutting on the part to be cut of the oil layer casing. The air hole (3323) is fluidly connected to the high-pressure gas output end of the air compressor, and is used to make the high-pressure inert gas ejected by the air compressor pass through the air hole (3323) and eject, so as to discharge the water body in the laser cutting area to form a local dry cutting environment and perform cutting by local dry method.

8. A laser perforation completion system for oil and gas wells according to claim 7, characterized in that, It further includes a transmission mechanism (5). The transmission mechanism (5) includes a flexible housing (51), an optical fiber (52), a high-pressure gas pipeline (53) and a power control wire harness (54). The flexible housing (51) is sleeved outside the optical fiber (52), the high-pressure gas pipeline (53) and the power control wire harness (54). The optical fiber (52) is optically connected to the laser hole (3324) and the laser emitter for realizing the transmission of laser energy. The high-pressure gas pipeline (53) is fluidly connected to the air hole (3323) and the air compressor for realizing the transportation of high-pressure inert gas. The power control wire harness (54) is electrically connected to the control system and the hole-opening device (3) for realizing the transmission of control signals and power supply.

9. The laser perforation completion system for oil and gas wells according to claim 7, characterized in that, A focusing lens (6) and a protective lens (61) are provided in the laser hole (3324), and the protective lens (61) is arranged outside the focusing lens (6).

10. A laser perforation completion method for oil and gas wells, characterized in that, Including: Lower the laser perforating device (3) from the carrier system (1) into the production casing, release the towing rope (21) of the towing mechanism (2), and under the action of the gravity of the laser perforating device (3) and the traction force of the towing rope (21), the laser perforating device (3) sinks to a predetermined perforating position of the production casing; The laser perforating mechanism (33) performs a laser cutting and perforating operation on a predetermined perforating position of the production casing through the pitching swing and radial feed of the laser cutting head (332); The laser perforating mechanism (33) cuts and perforates a designated perforating position of the production casing.

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