CN118361215B - Automatic cable-free type perforator of gun throwing - Google Patents

Abstract

The present invention discloses a cable-free perforator with automatic gun dropping, comprising a perforating gun, a CCL nipple, a buoyancy nipple located above the perforating gun, a hand-drop mechanism and a power supply nipple, and a control module located inside the buoyancy nipple; the buoyancy nipple is located above the hand-drop mechanism; the density of the buoyancy nipple is less than the density of the fluid in the well; the control module is signal-connected with the CCL nipple, the perforating gun and the hand-drop mechanism. The present invention provides a cable-free perforator with automatic gun dropping, so as to solve the problems of cumbersome perforating technology process, low automation, large manpower and time costs in the prior art, and achieve the purpose of automatically completing the perforating operation and reducing manpower and time costs.

Description

A cable-free perforator with automatic gun-dropping function

Technical Field

The invention relates to the field of oil and gas development, and in particular to a cable-free perforator with automatic gun-dropping function.

Background Art

Perforating operation is to send the perforating gun into the predetermined layer in the oil and gas well to perform explosive drilling, open the flow channel between the formation and the wellbore, and allow the formation fluid to enter the well smoothly. It is widely used in the completion operation of oil and gas development.

Traditional perforating operations are generally divided into cable perforating, tubing perforating and continuous tubing perforating. This type of operation method is to judge the arrival depth of the perforating gun in the well by the length of the cable, tubing or continuous tubing, and then after reaching the specified depth, the perforating gun is ignited by the cable or the perforating gun is detonated by pressurizing the pipe. After perforating, the delivery tool and the remaining related parts are taken out by the cable, tubing or continuous tubing. Therefore, the entire perforating operation process in the prior art requires a large amount of manual operation by the delivery tool, the process is cumbersome and the degree of automation is extremely low, and the operation process requires at least one trip to pull the drill or cable, which is not only time-consuming, but also occupies the wellhead space for a long time.

Summary of the invention

The present invention provides a cable-free perforator with automatic gun dropping, so as to solve the problems of complicated perforating technology process, low automation degree, large manpower and time cost in the prior art, and achieve the purpose of automatically completing the perforating operation and reducing manpower and time cost.

The present invention is achieved through the following technical solutions:

A cable-free perforator with automatic gun-dropping comprises a perforating gun, a CCL short section, a buoyancy short section located above the perforating gun, a hand-dropping mechanism and a power supply short section, and a control module located inside the buoyancy short section; the buoyancy short section is located above the hand-dropping mechanism;

The density of the buoyancy sub is less than the density of the fluid in the well;

The control module is signal-connected with the CCL short joint, the perforating gun and the release mechanism.

In view of the problems of complicated perforating technology process, low automation, high manpower and time costs in the prior art, the present invention proposes a cable-free perforator with automatic gun dropping, wherein the perforating gun can adopt the existing technology, which will not be elaborated here.

Those skilled in the art should understand that a CCL sub is a well tool sub that uses CCL technology (casing coupling positioning technology). CCL technology is a mature technical means for sensing casing couplings in wells based on the principle of electromagnetic induction, and is widely used in logging pipe strings after cementing of oil and gas wells. The present application integrates a CCL sub in the perforator, which enables the perforator to automatically determine the current depth of the tool after entering the well, and then automatically determine whether it has reached the set layer to be perforated. In addition, the release mechanism is a mechanism that can discard all tool pipe strings below it, and is used in the field of drilling and completion. When the tool pipe string is blocked or even stuck in the well, the pipe string below it is actively discarded, and the pipe string above it is recovered, and the wellhead and well space are freed up for the entry of the salvage tool into the well. Any release mechanism in the prior art that can be applied to the present application and plays a role in releasing the tool in the downhole tool pipe string can be applied to the present application.

Those skilled in the art should understand that the up/top and down/bottom used in this application to indicate the orientation are based on the direction toward the wellhead after the perforator enters the well as the direction toward the well bottom as the up/top and the direction toward the well bottom as the down/bottom.

The present application sets a buoyancy nipple so that its density is less than the density of the fluid in the well to ensure that it has lift in the well; technical personnel in this field should understand that oil and gas wells that require perforation and completion are all casing cemented, and the inside of the wellbore has not yet been connected to the formation before perforation. Therefore, the density of both the drilling fluid and the completion fluid in the well is known; and the density of the formation fluid such as oil, gas, water and their mixtures entering the well after perforation will not exceed the previous density of the fluid in the well. Therefore, the present application does not limit the material, structure, etc. of the buoyancy nipple. It is only necessary to ensure that the overall average density of the buoyancy nipple is less than the density of the fluid in the well to ensure that the buoyancy nipple always has lift in the well.

The buoyancy sub has a control module inside, and the control module is connected to the CCL sub signal to obtain the detection signal of the CCL sub in real time, so as to determine the depth of the perforator itself; the control module is connected to the perforating gun signal to control the detonation of the perforating gun to automatically complete the perforating operation; the buoyancy sub is connected to the release mechanism signal to leave the pipe string below the release mechanism in the well after the perforating operation is completed, and the buoyancy sub carries the control module automatically back to the wellhead for recovery under the action of buoyancy; it can also automatically drop the pipe string below when the perforator of the present application encounters obstruction or jam during entering the well, so that the buoyancy sub carrying the control module automatically returns to the wellhead for recovery, which is conducive to on-site engineers to formulate more reasonable jam release and salvage plans.

In the present application, the buoyancy sub is located above the release mechanism, the perforating gun and the power supply sub, to ensure that the perforating operation of detonating the perforating gun will not damage the buoyancy sub, and at the same time ensure that after the release mechanism is activated, the buoyancy sub can be separated from the rest of the pipe string as much as possible, fully ensuring its automatic return capability.

The power supply sub in the present application is used to supply power to all electrical equipment in the perforator, including but not limited to the control module, CCL sub, etc.

When this application is working, it is only necessary to preset the depth of the perforation or the corresponding casing coupling data in the control module in advance, and then the perforator can be dropped into the well from the wellhead as a whole. The perforator sinks in the well under the action of the overall gravity. During the sinking process, the buoyancy of the buoyancy short section can prevent the sinking speed from being too fast, so that the perforator as a whole sinks slowly, ensuring the positioning accuracy of the CCL short section, and thus improving the positioning accuracy of the perforation layer. During the sinking process of the perforator, the CCL short section senses each casing coupling in real time and sends the sensing signal to the control module. The control module determines the current depth of the perforating gun according to the casing coupling. When the perforating gun reaches the preset perforating depth, the perforating gun is controlled to detonate for perforating operation; then the control release mechanism is started, leaving the pipe string below it in the well. At this time, the buoyancy short section is separated from the left-behind pipe string, and automatically floats up under its own buoyancy until it returns to the wellhead. The staff recovers the buoyancy short section and the control module inside it from the wellhead.

It can be seen that the present application abandons the conventional technical concept of using cables, oil pipes or continuous oil pipes to deliver the perforating gun in the prior art. The entire perforating operation can be automatically completed by simply placing the perforator into the well, overcoming the defects of the prior art that a large number of manual operations and complicated processes are required, significantly reducing manpower and time consumption, and significantly improving the automation of the perforating operation. In addition, because the perforator of the present application sinks slowly under the action of the buoyancy short section, it takes a certain amount of time to reach the perforating layer. Therefore, during this period of time, the staff has a full time window to complete the installation and connection of the wellhead or oil test manifold. Therefore, the present application can also reduce the wellhead occupancy time during the slave well or batch drilling operation in the offshore oil field, realize the cross operation of the completion operation, and significantly improve the efficiency of the completion and/or oil test operation.

The present application is particularly suitable for automatic perforating operations in vertical wells and directional wells with a small inclination.

Furthermore, the buoyancy short section, the release mechanism, the power supply short section, the perforating gun, and the CCL short section are sequentially connected from top to bottom; and a first fishing head is arranged on the top of the buoyancy short section.

This solution clearly defines the relative position relationship of each tool, so that the buoyancy sub is located at the top of the perforator and is directly connected to the release mechanism, so as to ensure that after the release, the buoyancy sub will not be disturbed by the gravity of the other tools and can smoothly float up to the inlet by itself; the power supply sub, perforating gun and CCL sub are all located below the release mechanism and are left in the well after the release; the power supply sub is located above the perforating gun, so that after the perforating gun is detonated, the power supply sub is not disturbed and can still supply power to the control module, avoiding the situation where the power supply circuit between the power supply sub and the control module is damaged when the perforating gun is detonated, resulting in the inability to control the start of the loss mechanism.

This solution separates the CCL pup joint from the power supply pup joint by a perforating gun, thereby preventing the working current of the power supply pup joint from interfering with the CCL pup joint's identification of the casing coupling, and can effectively improve the accuracy of the automatic positioning of this application.

In addition, a first salvaging head is arranged on the top of the buoyancy sub. When the perforator is stuck during the process of entering the well, or the buoyancy sub is blocked during the process of returning, a salvaging tool matching the first salvaging head can be lowered from the wellhead to salvage the perforator as a whole or the buoyancy sub alone, which is convenient for handling accident conditions at the operation site.

Furthermore, a chip compartment is provided inside the buoyancy sub, and the control module is located inside the chip compartment; a storage module is also provided inside the chip compartment;

The input end of the control module is connected to the CCL short joint signal, and the output end of the control module is connected to the perforating gun, the release mechanism and the storage module signal;

The control module is used to control the detonation of the perforating gun and the activation of the release mechanism;

The storage module is used to store the sensing signal of the CCL short section and the control signal sent by the control module.

In this solution, the sensing signal of the CCL sub is transmitted to the control module, which controls the detonation of the perforating gun according to the sensing signal of the CCL sub, and controls the release mechanism to start after the perforating gun is detonated; at the same time, the control module also transmits the sensing signal of the CCL sub received and the control signals sent to the storage module for local storage. After the buoyancy sub floats out of the well, the staff can read the data stored in the storage module, and then accurately analyze and grasp the complete process and completion status of the automatic perforating operation.

In addition, when the perforator encounters an obstruction during the process of entering the well, and the obstruction point is located below the buoyancy short joint, this solution can also control the loss mechanism to start, discard the lower pipe string, and make the buoyancy short joint float to the wellhead. At this time, the staff can read the data stored in the storage module, and use it as a basis to analyze and determine the specific cause of the obstruction, and then formulate a more targeted salvage plan, thereby improving the work safety of this application.

Furthermore, the release mechanism includes a second salvaging head with a hollow interior, a spring claw inserted into the interior of the second salvaging head from the top of the second salvaging head, and a locking mechanism for locking the spring claw inside the second salvaging head; the top of the spring claw is fixedly connected to the bottom end of the buoyancy short joint; and the control module is used to unlock the locking mechanism.

During the in-depth research, the applicant found that a type of downhole tool release tool in the prior art is to release the tool by high-pressure shear pins through the internal pressure of the tool. This type of lost tool is not suitable for the cableless operation conditions of this application. There is also a type of pyrotechnic release tool used in cable operation in the prior art, but its principle is still to release the tool by shearing the pins, and it has the defects of complex structure, excessive overall weight of the tool, which is not conducive to controlling the automatic falling speed, and it is more complicated to salvage the fish in the well after the release, and the success rate of salvage is difficult to effectively guarantee. In addition, in this application, when the perforator encounters serious obstruction below the release during the well entry process, and the perforator cannot be salvaged out of the well as a whole by salvaging the buoyancy short section, there will be a large operational hazard, which may even cause the well to fail to be put into production smoothly in serious cases.

In order to overcome the above defects, the present invention designs a release mechanism specifically used in the present application, wherein the second salvage head is configured as a hollow structure on the basis of the conventional salvage head structure, and a spring claw is inserted into the second salvage head from the top end thereof, the top end of the spring claw is located outside the second salvage head and is used to be fixedly connected with the bottom end of the buoyancy short section, and the spring claw is locked inside the second salvage head by a locking mechanism, so as to realize the fixed connection between the spring claw and the second salvage head under normal working conditions, thereby ensuring the relative fixation of the second salvage head and the release mechanism above under normal working conditions. When it is necessary to release the hand, the control module controls the locking mechanism to unlock and release the lock of the spring claw, at which time the spring claw releases the fixed connection with the second salvage head under the action of its own elastic force, and the buoyancy short section floats up, driving the spring claw to detach from the inside of the second salvage head and float together to the wellhead. Afterwards, a salvage tool matching the second salvage head can be lowered from the wellhead to salvage the tool left in the well.

The release mechanism of the present solution does not require hydraulic drive, and its release principle does not rely on shear pins, so it is more suitable for the cable-free perforating operation of the present application. The release mechanism integrates the second fishing head, and the spring claw is assembled inside the second fishing head. The structure is simple and ingenious, which effectively reduces the volume and length of the release tool, and is more conducive to controlling the total weight of the perforator, thereby facilitating the perforator to automatically sink into the well at a more stable and slow speed. The release can be performed at any time, and the release can be performed in time when the perforator is stuck during the process of entering the well. When the perforator cannot be salvaged out of the well as a whole by salvaging the buoyancy short section, the release mechanism can provide a backup salvaging solution, which significantly improves the safety of the perforating operation.

Furthermore, an axially penetrating through hole is provided inside the second fishing head, and the through hole includes an expanded diameter portion;

The spring claw comprises a plurality of spring pieces uniformly distributed in the circumferential direction, and a positioning block extending radially outward is arranged on the spring piece; the top surface of the enlarged diameter portion and the top surface of the positioning block are mutually matching inclined surfaces; the inclined surface gradually inclines upward from the outside to the inside along the radial direction;

The locking mechanism includes a support member clamped inside a plurality of positioning blocks, a detonating cord located inside the support member, and a first elastic member in contact with the bottom surface of the spring claw, wherein the first elastic member is used to apply an upward thrust to the spring claw;

The control module is used to control the detonation of the detonation index.

This scheme meets the hollow structure of the second fishing head through a through hole, wherein the expanded diameter portion, as the name implies, is a portion with an expanded inner diameter, that is, the inner diameter of the expanded diameter portion is larger than the inner diameter of the aforementioned through hole. The claw is provided with a number of circumferentially evenly distributed spring pieces, and the positioning blocks on the spring pieces extend radially outward and match the expanded diameter portion. In a natural state, each spring piece is retracted inward under the action of prestress, so that each positioning block is retracted to a state where it can smoothly pass through the internal through hole of the second fishing head. When the present scheme is not lost, the support member is supported inside each positioning block, that is, the support member overcomes the elastic reset force of each spring piece, so that each positioning block is always stretched open in the expanded diameter portion, and because the first elastic member applies an upward force to the claw from the bottom, the inclined surface of the top of each positioning block abuts against the inclined surface at the top of the expanded diameter portion. At this time, due to the existence of the support member, each claw cannot be retracted inward, and the claw can be locked.

A detonating cord controlled by a control module is arranged inside the support member. When it is necessary to let go, the method of unlocking the locking mechanism is: the control module controls the detonating cord to detonate, the detonating cord blows the support member into pieces, and each shrapnel retracts inwardly under the action of the elastic restoring force. At the same time, the spring claw is pushed upward as a whole under the action of the first elastic member, and each positioning block gradually leaves the range of the expanded diameter portion along the inclined surface.

Furthermore, the release mechanism and the power supply short section are connected via a double male connector, a ring groove is provided on the top surface of the double male connector, a mounting seat matching the first elastic member is connected in the ring groove, and the first elastic member is arranged in the mounting seat.

This solution connects the release mechanism and the power supply short section through a double male connector, and at the same time provides an installation position for the mounting seat of the first elastic member. The mounting seat is axially stable through the annular groove, thereby ensuring the stable installation of the first elastic member and ensuring that the first elastic member can apply an upward thrust to the spring claw.

Furthermore, the perforating gun and the CCL short section are connected via a double-ended contact joint, one end of which is connected to a signal line and the other end is connected to an output guide rod of the CCL short section; the signal line passes through the perforating gun and is connected to the control module.

In the prior art, since it is necessary to consider the problem of entanglement, knotting, or even twisting of the wire, the signal connection between the perforating gun and the other adjacent tools is generally achieved by opening a bypass. This signal connection method has the disadvantages of cumbersome and complicated installation process, high requirements for bypass hole sealing, and the need for a large amount of sealing treatment. Specifically in this application, since the CCL short section is set below the perforating gun, the signal line connecting the CCL short section and the control module must pass through the inside of the perforating gun. Therefore, if traditional wires are used for signal connection, there will be a serious risk of entanglement, knotting, or even twisting. If a bypass signal connection is used, both the instruments inside the CCL and the perforating gun have extremely high sealing requirements. Once the sealing fails, the perforator will inevitably fail to work, so there are great hidden dangers in the operation.

In order to overcome the above problems, this solution uses a double-ended contact joint to achieve the connection between the perforating gun and the CCL short joint. The top of the double-ended contact joint is connected to the bottom of the perforating gun, and the bottom of the double-ended contact joint is connected to the top of the CCL short joint. The signal communication is realized inside the double-ended contact joint. The induction signal of the CCL short joint is transmitted to the bottom of the double-ended contact joint through the output guide rod and then transmitted to the signal line through the top of the double-ended contact joint. This connection method can ensure stable and safe signal transmission between the CCL short circuit and the control module, while avoiding the need to set up a large number of sealing structures, which is conducive to simplifying the tool structure and reducing production and use costs.

Furthermore, the double-ended contact connector includes a shell, wherein a first chamber and a second chamber are arranged in an upper and lower manner inside the shell, a first communication contact is arranged at the bottom of the first chamber, and a second communication contact is arranged at the top of the second chamber, and the first communication contact and the second communication contact are in contact with each other;

It also includes a first slider slidably fitted in the first cavity along the axial direction, and a second slider slidably fitted in the second cavity along the axial direction, a second elastic member is arranged between the first slider and the first communication contact, and a third elastic member is arranged between the second slider and the second communication contact;

The first slider and the second slider are both conductors, and the first slider is electrically connected to the signal line, and the second slider is in contact with the output guide rod of the CCL short section.

In this solution, the induction signal of the CCL short section is transmitted to the second slider via the output guide rod, transmitted to the first communication contact via the third elastic member and the second communication contact, and then transmitted to the first slider, and then transmitted to the signal line via the second elastic member and the first slider. Due to the presence of the first elastic member and the second elastic member, the first communication contact and the second communication contact can always maintain close contact to ensure stable signal transmission; at the same time, the first slider and the second slider can slide appropriately along the axial direction, thereby ensuring that the shell of the double-headed contact joint is stably threaded and sealed with the perforating gun and the CCL short section, and the connection process will not cause any interference to the signal transmission, which significantly reduces the installation difficulty of this application, improves the installation efficiency, and ensures the communication quality.

Furthermore, a positioning seat is provided at the bottom of the perforating gun or the top of the double-headed contact joint, an insulating sheath is provided inside the positioning seat, and also includes a power connection post located inside the insulating sheath, the signal line is wound around the power connection post and electrically connected to the power connection post, and the first sliding block abuts against the bottom end of the power connection post.

This solution provides an assembly position for the insulating sheath through a positioning seat to protect the internal power connection post and signal line terminal.

Furthermore, a first limiter for limiting the upward movement of the first slider is provided in the first chamber, and a second limiter for limiting the downward movement of the second slider is provided in the second chamber; and a plurality of clamping devices for positioning the signal wire are provided in the perforating gun.

This solution provides travel limits for the axial sliding of the first slider and the second slider through the first limiter and the second limiter, respectively, to ensure that the first slider and the second slider can maintain contact with the second elastic member and the third elastic member, respectively, so as to ensure the stability of the electrical signal transmission. In addition, since the perforating gun has inherent equipment such as perforating bullets and electric detonators, if the signal line passes through the perforating gun at will, it may interfere with such inherent equipment, which is not conducive to the safe use of the perforating gun. Therefore, this solution temporarily positions the signal line passing through the perforating gun through a plurality of clamping devices, so as to reduce the interference of the signal line with the inherent equipment in the perforating gun and improve the safety of the perforating gun.

Compared with the prior art, the present invention has the following advantages and beneficial effects:

1. The present invention discloses a cable-free perforator with automatic gun dropping, which abandons the conventional technical concept of using cables, oil pipes or continuous oil pipes to send perforating guns in the prior art. The whole perforating operation can be automatically completed by only dropping the perforator into the well, thus overcoming the defects of the prior art that a large number of manual operations are required and the process is cumbersome, significantly reducing the consumption of manpower and time, and significantly improving the automation degree of the perforating operation.

2. When used in the drilling of offshore oil fields or batch drilling, the present invention can also reduce the wellhead occupancy time, realize the cross operation of well completion operations, and significantly improve the efficiency of well completion and/or oil testing operations.

3. The present invention separates the CCL pup joint from the power supply pup joint by a perforating gun, thereby preventing the working current of the power supply pup joint from interfering with the CCL pup joint's identification of the casing coupling, and can effectively improve the accuracy of automatic positioning.

4. The present invention can adopt a double salvage head structure, and can perform overall salvage or partial salvage according to specific blocking conditions. It can adapt to salvage operations under various blocking conditions and significantly improve the ability to handle accident conditions.

5. After the normal perforating operation is completed, the staff can read the data stored in the storage module to accurately analyze and grasp the complete process and completion status of the automatic perforating operation; when encountering accident conditions such as blockage, the staff can also read the data stored in the storage module to analyze and determine the specific cause of the blockage, and then formulate a more targeted salvage plan to improve the work safety of this application.

6. A release mechanism particularly suitable for the present application is designed, which does not require hydraulic drive and its release principle does not rely on shear pins, and is more suitable for the cable-free perforating operation of the present application; the release mechanism integrates a second salvaging head, and the spring claw is assembled inside the second salvaging head. The structure is simple and ingenious, which effectively reduces the volume and length of the release tool, and is more conducive to controlling the total weight of the perforator, thereby facilitating the perforator to automatically sink into the well at a more stable and slow speed; the release can be performed at any time, and the release can be performed in time when the perforator is stuck during the process of entering the well. When the perforator cannot be salvaged out of the well as a whole by salvaging the buoyancy short section, the release mechanism can provide a backup salvaging plan, which significantly improves the safety of the perforating operation.

7. The double-ended contact connector ensures stable and safe signal transmission between the CCL short circuit and the control module, while avoiding the need to set up a large number of sealing structures, which is conducive to simplifying the tool structure and reducing production and use costs.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

FIG1 is a side view of a specific embodiment of the present invention;

FIG2 is a schematic diagram of a half-section structure of a specific embodiment of the present invention;

FIG3 is a cross-sectional view of a release mechanism in a specific embodiment of the present invention;

FIG4 is a schematic diagram of a half-section structure of a release mechanism in a specific implementation of the present invention;

FIG5 is a schematic diagram of a half-section structure of a second fishing head in a specific implementation of the present invention;

FIG6 is a schematic diagram of the structure of a bullet claw in a specific embodiment of the present invention;

FIG7 is a schematic diagram of a half-section structure of a bullet claw in a specific embodiment of the present invention;

FIG8 is a schematic diagram of the structure of a double-ended contact connector in a specific implementation of the present invention;

FIG9 is a schematic diagram of a half-section structure of a double-ended contact connector in a specific embodiment of the present invention;

FIG. 10 is a schematic diagram of the routing of the signal line inside the perforating gun in a specific implementation of the present invention.

Marks and corresponding parts names in the attached drawings:

1-perforating gun, 2-CCL short section, 3-buoyancy short section, 4-first fishing head, 5-hand release mechanism, 501-second fishing head, 502-claw, 5021-shrapnel, 5022-positioning block, 503-through hole, 504-expanded diameter part, 505-support part, 506-detonating cord, 507-first elastic part, 508-mounting seat, 6-power supply short section, 7-chip compartment, 8-double male connector, 9-double-head contact point Head, 901-shell, 902-first chamber, 903-second chamber, 904-second communication contact, 905-first slider, 906-second slider, 907-second elastic member, 908-third elastic member, 909-positioning seat, 910-insulating sheath, 911-electrical connection post, 912-first limiting member, 913-second limiting member, 914-first communication contact, 10-signal line, 11-clamping device.

DETAILED DESCRIPTION

In order to make the objects, technical solutions and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with examples and drawings. The schematic embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention. In the description of the present application, it should be understood that the orientation or positional relationship indicated by terms such as "front", "rear", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "inside", "outside", etc. is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present application.

Embodiment 1:

As shown in FIG1 and FIG2 , a cable-free perforator with automatic gun-dropping includes a perforating gun 1, a CCL subsection 2, a buoyancy subsection 3, a release mechanism 5 and a power supply subsection 6 located above the perforating gun 1, and a control module located inside the buoyancy subsection 3; the buoyancy subsection 3 is located above the release mechanism 5; the density of the buoyancy subsection 3 is less than the density of the fluid in the well; the control module is signal-connected to the CCL subsection 2, the perforating gun 1 and the release mechanism 5.

In this embodiment, the buoyancy sub 3, the release mechanism 5, the power supply sub 6, the perforating gun 1, and the CCL sub 2 are sequentially connected from top to bottom; a first fishing head 4 is arranged on the top of the buoyancy sub 3.

In this embodiment, a chip bin 7 is provided inside the buoyancy sub 3, and a control module is located inside the chip bin 7; a storage module is also provided inside the chip bin 7; an input end of the control module is signal-connected to the CCL sub 2, and an output end of the control module is signal-connected to the perforating gun 1, the release mechanism 5 and the storage module;

The control module is used to control the detonation of the perforating gun 1 and the activation of the release mechanism 5; the storage module is used to store the sensing signal of the CCL short section 2 and the control signal issued by the control module.

Among them, the buoyancy short section 3 can adopt a hollow structure to make the average density lower than the density of the fluid in the well, or it can be made of low-density materials to make the average density lower than the density of the fluid in the well. The length of the buoyancy short section 3 can be adaptively set according to specific working conditions. The buoyancy short section 3 can be an integrated short section, or it can be composed of several short sections spliced in sequence. In addition, the control module can be implemented by an existing control chip, and the storage module can be implemented by an existing storage chip or storage device.

Preferably, the buoyancy subsection 3 can be made of AMMT-500 series solid buoyancy materials.

More preferably, the shells of the power supply nipple, the perforating gun, the CCL nipple, etc. can all be made of existing soluble alloys.

More preferably, the bottom end of the CCL short section 2 is fixedly connected to the gun tail which serves as a guide.

More preferably, a battery compartment is provided inside the power supply short section 6, and a storage battery is installed in the battery compartment.

The perforator of the present application is particularly suitable for performing automatic perforating operations in vertical wells or directional wells with a well inclination within 10°.

Embodiment 2:

A cable-free perforator with automatic gun-dropping, based on the first embodiment, a releasing mechanism 5 of the present embodiment is shown in FIGS. 3 to 7, comprising a second fishing head 501 with a hollow interior, a spring claw 502 inserted into the second fishing head 501 from the top of the second fishing head 501, and a locking mechanism for locking the spring claw 502 inside the second fishing head 501; the top of the spring claw 502 is fixedly connected to the bottom of the buoyancy sub 3; and the control module is used to unlock the locking mechanism.

The specific structure of the second fishing head 501 is shown in FIG. 5 , wherein an axially penetrating through hole 503 is disposed inside the second fishing head 501 , and the through hole 503 includes an enlarged diameter portion 504 .

As shown in FIG. 6 and FIG. 7 , the spring claw 502 includes a plurality of spring pieces 5021 uniformly distributed in the circumferential direction, and a positioning block 5022 extending radially outward is provided on the spring piece 5021; the top surface of the enlarged diameter portion 504 and the top surface of the positioning block 5022 are mutually matching inclined surfaces; the inclined surface is gradually inclined upward from the outside to the inside along the radial direction;

The locking mechanism includes a support member 505 clamped inside a plurality of positioning blocks 5022 , a detonating cord 506 located inside the support member 505 , and a first elastic member 507 in contact with the bottom surface of the spring claw 502 . The first elastic member 507 is used to apply an upward thrust to the spring claw 502 .

In this embodiment, the control module unlocks the locking mechanism by controlling the detonation of the detonating cord 506 .

In this embodiment, the spring pieces 5021 are located at the bottom end of the spring claws 502 , and there is a gap between two adjacent spring pieces 5021 ; the positioning block 5022 is located at the bottom end of the spring pieces 5021 , and the positioning block 5022 and the spring pieces 5021 are integrally formed.

In this embodiment, the support member 505 is made of a material that is easily broken into pieces, such as AMMT-500 series solid buoyancy material; in addition, the first elastic member 507 is a spring in a compressed state.

In a more preferred embodiment, the release mechanism 5 and the power supply short section 6 are connected via a double male connector 8, a ring groove is provided on the top surface of the double male connector 8, a mounting seat 508 matching the first elastic member 507 is connected in the ring groove, and the first elastic member 507 is arranged in the mounting seat 508. Preferably, the top of the double male connector 8 is threadedly connected to the bottom of the second fishing head, and the bottom of the double male connector 8 is threadedly connected to the top of the power supply short section 6. The mounting seat 508 preferably uses a spring seat matching the first elastic member 507.

In a more preferred embodiment, the power supply sub 6 and the perforating gun 1 may also be connected via a double male connector.

Embodiment 3:

A cable-free perforator with automatic gun dropping is disclosed. Based on Embodiment 1 or 2, a perforating gun 1 and a CCL short section 2 are connected via a double-ended contact joint 9. The double-ended contact joint 9 is shown in FIGS. 8 and 9 , one end of which is connected to a signal line 10 and the other end is connected to an output guide rod 201 of the CCL short section 2. The signal line 10 passes through the perforating gun 1 and is connected to a control module.

The double-ended contact connector 9 includes a housing 901, wherein a first chamber 902 and a second chamber 903 are arranged in the housing 901, wherein a first communication contact 914 is arranged at the bottom of the first chamber 902, and a second communication contact 904 is arranged at the top of the second chamber 903, and the first communication contact 914 and the second communication contact 904 are in contact with each other;

It also includes a first slider 905 that slides axially in the first chamber 902, and a second slider 906 that slides axially in the second chamber 903. A second elastic member 907 is arranged between the first slider 905 and the first communication contact 914, and a third elastic member 908 is arranged between the second slider 906 and the second communication contact 904. The first slider 905 is electrically connected to the signal line 10, and the second slider 906 abuts against the output guide rod 201 of the CCL short section 2.

A positioning seat 909 is provided at the bottom of the perforating gun 1 or the top of the double-headed contact connector 9, and an insulating sheath 910 is provided inside the positioning seat 909. It also includes a power connection post 911 located inside the insulating sheath 910. The signal line 10 is wound around the power connection post 911 and is electrically connected to the power connection post 911. The first slider 905 abuts against the bottom end of the power connection post 911.

A first stopper 912 for limiting the upward movement of the first slider 905 is disposed in the first chamber 902 , and a second stopper 913 for limiting the downward movement of the second slider 906 is disposed in the second chamber 903 .

In this embodiment, the first slider 905, the second slider 906, the second elastic member 907, and the third elastic member 908 are all conductors, preferably made of metal materials; the second elastic member 907 and the third elastic member 908 are both springs in a compressed state.

In a more preferred embodiment, as shown in FIG. 10 , a plurality of clamping devices 11 for positioning the signal line 10 are provided in the perforating gun to minimize the interference of the signal line 10 on the perforating bullets etc. in the gun; the clamping devices 11 can be fixedly mounted on the inner wall of the perforating gun.

Embodiment 4:

An automatic gun-dropping cable-free perforating method is implemented based on the perforator in any of the above embodiments, comprising the following steps:

S1. Preset the perforation depth or corresponding casing coupling data required for this operation in the control module, and drop the perforator into the well from the wellhead as a whole;

S2. The perforator as a whole sinks in the well under the action of gravity. The CCL sub senses each casing coupling in real time and sends the sensing signal to the control module. The control module determines the current depth of the perforator according to the casing coupling.

S3. When the perforating gun reaches the preset perforating depth, the control module controls the perforating gun to detonate and perform the perforating operation;

S4, the control module controls the release mechanism to start, leaving the pipe string below it in the well;

S5. The buoyancy sub automatically floats up under the action of its own buoyancy until it returns to the wellhead, and the staff recovers the buoyancy sub and the control module inside it from the wellhead.

Preferably, in step S1, complete casing table data of the well can also be input into the control module, which is conducive to the control module to confirm the perforation position more accurately.

Preferably, the time interval between executing step S3 and step S4 is greater than 1-2 seconds.

Preferably, step S4 specifically includes:

The control module detonates the detonating cord 506 to shatter the support member 505, and under the combined action of the first elastic member 507 and the buoyancy short section 3, the spring claw 502 moves upward as a whole;

As the claws 502 move upward, the spring sheets 5021 drive the positioning blocks 5022 to move upward synchronously, and the positioning blocks 5022 gradually leave the range of the enlarged diameter portion 504 along the inclined surface and retract inward until the claws 502 completely leave the through hole 503 .

Embodiment 5:

A salvage method for a cable-free perforator with automatic gun-dropping function, based on any of the above embodiments, comprises a salvage step when encountering an obstruction and a salvage step when encountering a jam.

The obstruction salvage steps include:

During the sinking process of the perforator, if the perforator encounters resistance when drilling down, a fishing tool matching the first fishing head 4 is lowered from the wellhead to fish out the perforator as a whole;

If the overall salvage of the perforator fails, a release command is sent to the control module through a pulse signal from the wellhead, or the control module monitors that the speed is 0 for a duration exceeding a set threshold, and the control module controls the release mechanism to start;

Check at the wellhead whether the buoyancy sub 3 floats up to the wellhead:

If yes, take out the buoyancy sub 3, read the data in the storage module, and manually analyze the resistance situation; based on the analysis results, select a salvage tool that matches the second salvage head 501 and is adapted to the current resistance situation, and lower it from the wellhead to salvage the remaining pipe string;

If not, conduct well clearance operation or backfill sidetracking.

The stuck salvage steps include:

During the process of the perforating gun completing perforation and the buoyancy sub 3 floating up, if the buoyancy sub 3 encounters resistance in floating up, a fishing tool matching the first fishing head 4 is lowered from the wellhead to fish out the buoyancy sub.

Among them, the judgment of the perforator encountering resistance when drilling down and the buoyancy short section 3 encountering jam when floating up can be realized by installing a velocity sensor, an acceleration sensor or a hydraulic sensor on the buoyancy short section 3, which is not difficult for those skilled in the art to realize. Alternatively, the judgment can be made by the following method:

During the sinking process of the perforator, the control module calculates the sinking speed according to the sensing signal of CCL sub 2. When the acceleration sinking speed suddenly changes to 0 and the perforator has not reached the bottom of the well, it is recognized that the perforator encounters resistance when drilling down;

During the floating process of the buoyancy sub 3, the time required for the buoyancy sub 3 to float to the wellhead is estimated according to the corresponding depth of the perforated layer; after reaching the aforementioned required time, immediately or after a period of time, it is observed whether the buoyancy sub 3 successfully floats to the wellhead. If not, it is determined that the buoyancy sub 3 is stuck while floating.

The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In addition, the term "connected" used in this article can be directly connected or indirectly connected via other components without special explanation.

Claims (8)

1. A cable-free perforator with automatic gun-dropping, comprising a perforating gun (1), characterized in that it also comprises a CCL short section (2), a buoyancy short section (3) located above the perforating gun (1), a hand-dropping mechanism (5) and a power supply short section (6), and a control module located inside the buoyancy short section (3); the buoyancy short section (3) is located above the hand-dropping mechanism (5); The density of the buoyancy sub (3) is less than the density of the fluid in the well; The control module is signal-connected to the CCL sub (2), the perforating gun (1) and the release mechanism (5); The perforating gun (1) and the CCL short section (2) are connected via a double-ended contact joint (9); one end of the double-ended contact joint (9) is connected to a signal line (10), and the other end is connected to an output guide rod (201) of the CCL short section (2); the signal line (10) passes through the perforating gun (1) and is connected to the control module; The double-ended contact connector (9) comprises a housing (901), wherein a first chamber (902) and a second chamber (903) are arranged in the housing (901) and are arranged in an upper and lower manner, a first communication contact (914) is arranged at the bottom of the first chamber (902), and a second communication contact (904) is arranged at the top of the second chamber (903), and the first communication contact (914) and the second communication contact (904) are in contact with each other; It also includes a first slider (905) slidably engaged in the first chamber (902) along the axial direction, and a second slider (906) slidably engaged in the second chamber (903) along the axial direction, a second elastic member (907) being arranged between the first slider (905) and the first communication contact (914), and a third elastic member (908) being arranged between the second slider (906) and the second communication contact (904); The first slider (905) and the second slider (906) are both conductors, and the first slider (905) is electrically connected to the signal line (10), and the second slider (906) is in contact with the output guide rod (201) of the CCL short section (2). 2. The cable-free perforator with automatic gun-dropping according to claim 1, characterized in that the buoyancy subsection (3), the hand-dropping mechanism (5), the power supply subsection (6), the perforating gun (1), and the CCL subsection (2) are sequentially connected from top to bottom; and a first fishing head (4) is arranged on the top of the buoyancy subsection (3). 3. The cable-free perforator with automatic gun-dropping according to claim 1, characterized in that a chip compartment (7) is arranged inside the buoyancy sub (3), and the control module is located inside the chip compartment (7); a storage module is also arranged inside the chip compartment (7); The input end of the control module is signal-connected to the CCL sub (2), and the output end of the control module is signal-connected to the perforating gun (1), the release mechanism (5) and the storage module; The control module is used to control the detonation of the perforating gun (1) and the activation of the release mechanism (5); The storage module is used to store the sensing signal of the CCL short section (2) and the control signal issued by the control module. 4. The cable-free perforator with automatic gun-dropping according to claim 1, characterized in that the hand-dropping mechanism (5) comprises a second fishing head (501) with a hollow interior, a spring claw (502) inserted from the top of the second fishing head (501) into the interior of the second fishing head (501), and a locking mechanism for locking the spring claw (502) inside the second fishing head (501); the top of the spring claw (502) is fixedly connected to the bottom of the buoyancy sub (3); and the control module is used to unlock the locking mechanism. 5. The automatic gun-discarding cable-free perforator according to claim 4, characterized in that an axially penetrating through hole (503) is provided inside the second fishing head (501), and the through hole (503) includes an expanded diameter portion (504); The spring claw (502) comprises a plurality of spring pieces (5021) uniformly distributed in the circumferential direction, and a positioning block (5022) extending radially outward is provided on the spring piece (5021); the top surface of the diameter expansion portion (504) and the top surface of the positioning block (5022) are mutually matching inclined surfaces; the inclined surface gradually inclines upward from the outside to the inside along the radial direction; The locking mechanism comprises a support member (505) clamped inside a plurality of positioning blocks (5022), a detonating cord (506) located inside the support member (505), and a first elastic member (507) in contact with the bottom surface of the spring claw (502), wherein the first elastic member (507) is used to apply an upward thrust to the spring claw (502); The control module is used to control the detonation of the detonating cord (506). 6. A cable-free perforator with automatic gun-dropping according to claim 5, characterized in that the release mechanism (5) and the power supply short section (6) are connected via a double male connector (8), a ring groove is provided on the top surface of the double male connector (8), a mounting seat (508) matching the first elastic member (507) is connected in the ring groove, and the first elastic member (507) is arranged in the mounting seat (508). 7. A cable-free perforator with automatic gun-dropping according to claim 1, characterized in that a positioning seat (909) is provided at the bottom of the perforating gun (1) or the top of the double-headed contact connector (9), an insulating sheath (910) is provided inside the positioning seat (909), and also includes a power connection post (911) located inside the insulating sheath (910), the signal line (10) is wound around the power connection post (911) and is electrically connected to the power connection post (911), and the first slider (905) abuts against the bottom end of the power connection post (911). 8. The cable-free perforator with automatic gun-dropping according to claim 1, characterized in that a first limiter (912) for limiting the upward movement of the first slider (905) is provided in the first chamber (902), and a second limiter (913) for limiting the downward movement of the second slider (906) is provided in the second chamber (903); and a plurality of clamping devices (11) for positioning the signal line (10) are provided in the perforating gun (1).