CN116427873B - An oil and gas production pipe string cutter - Google Patents

Abstract

The invention discloses an oil and gas production pipe string cutter, which includes a traveling sub-section, a centering sub-section, an anchoring rotating sub-section and a cutting sub-section; when the traveling sub-section is activated, the cutter is allowed to travel along the axial direction in the pipeline; When the centering sub is activated, the cutter is centered in the pipeline; when the anchoring rotating sub is activated, the cutter is rotated around the axis of the pipeline at the current well depth; when the cutting sub is activated, the pipe wall is cut. The present invention provides an oil and gas production pipe string cutter to solve the problems in the prior art that the downhole pipe wall cutting technology used in the oil and gas field is limited by the size of the feeding tool and the well inclination, and has low precision and large pollution, and realizes It is capable of accurately cutting various types of underground pipes under various well inclinations.

Description

An oil and gas production pipe string cutter

Technical field

The invention relates to the field of oil and gas development, and in particular to an oil and gas production pipe string cutter.

Background technique

In the drilling and development of oil and gas, the types of downhole pipelines mainly include drill pipes, casings, tubing, etc. There are many working conditions for cutting downhole pipelines in engineering, such as: when repairing wells with damaged casings, the damaged sections of casings need to be cut and salvaged in sections; when permanently abandoning wells in offshore oil fields, underwater wellheads need to be removed; Recovery of oil and casing pipes, cutting of oil pipes during well workover operations, and handling of stuck pipe accidents of various downhole pipe strings, etc.

In traditional technology, the cutting of casing is generally achieved by hydraulic cutting, chemical blasting or corrosion, while the cutting of drill pipes and tubing is mainly done by chemical blasting. Among them, hydraulic cutting technology generally requires drill pipe, oil pipe or coiled tubing as the feeding tool. Due to the size limit of the feeding tool, it is difficult to apply to the cutting operation of drill pipe and oil pipe itself; while chemical cutting technology cannot accurately control the cutting position. It is easy to have adhesion areas after cutting, and it is easy to cause irreversible damage and contamination to the formation near the well wall zone.

In addition, as a mature underground operation method, wireline operation has the advantage of not being limited by the size of the feeding tool, but it is difficult to apply to construction in well structures such as highly deviated directional wells, extended reach wells, and horizontal wells. The limitations are large.

In summary, there is an urgent need to design a pipe wall cutting tool that can take into account various types of downhole pipe strings such as drill pipe, casing, and tubing, and can be used in various well inclinations.

Contents of the invention

The present invention provides an oil and gas production pipe string cutter to solve the problems in the prior art that the downhole pipe wall cutting technology used in the oil and gas field is limited by the size of the feeding tool and the well inclination, and has low precision and large pollution, and realizes It is capable of accurately cutting various types of underground pipes under various well inclinations.

The present invention is realized through the following technical solutions:

An oil and gas production pipe string cutter includes a traveling sub-section, a centering sub-section, an anchoring rotating sub-section and a cutting sub-section;

When the walking nipple is started, the cutter moves axially in the pipe;

When the centralizing nipple is activated, the cutter is centered in the pipe;

When the anchor rotating sub-joint is started, the cutter maintains the current well depth and rotates around the pipeline axis;

The cutting nipple cuts the pipe wall when activated.

In order to solve the problems of the existing downhole pipe wall cutting technology used in the field of oil and gas, which is limited by the size of the feeding tool and the well inclination, and has low precision and high pollution, the present invention proposes an oil and gas production pipe string cutter. The tool includes four parts: a traveling sub-section, a centering sub-section, an anchoring rotating sub-section and a cutting sub-section. This application is used as an underground tool. The sub-sections are distributed along the axial direction, that is, along the up and down direction of the wellbore trajectory in the working state. , their mutual positional relationship is not limited here. The walking sub-joint of this application is used to make the entire cutter walk along the axial direction of the pipeline in the underground pipeline when needed. Its specific walking method is not limited here, and can be realized by any existing walking method in the pipe; The centralizing sub-joint is used to centralize the entire cutter in the pipeline when needed. The specific centralizing method is not limited here. It only needs to meet the requirements that the centralizing sub-joint can exert its centralizing function when the centralizing sub-joint is activated and the centralizing sub-joint can be used to centralize the cutter when necessary. It is enough that the inner contraction does not exert the righting function; the anchoring rotating sub-joint of this application is used to position the entire cutter at the current depth when needed, and to rotate the cutter around the axis of the pipeline and along the circumferential direction of the pipeline, thereby overcoming the problem Conventional wireline operations have the disadvantage of being unable to effectively rotate downhole tools; the cutting nipple of this application is used to achieve the cutting function of the pipe wall when needed.

When this application is used: first, the entire cutter is sent into the underground pipe by the cable. During the feeding process, the centering nipple can be activated to reduce the collision between the tool body and the pipe wall and prevent the tool from lying on the lower well wall of the directional well or horizontal section. ; Determine the depth of tool descent based on the cable feeding length, and always pay attention to the cable tension during the feeding process. If the tension decreases abnormally, combine the well structure to determine whether the tool is blocked or the well inclination is too large, and control the short travel time. Start the section and actively walk through the blocked area, or continue to advance in the large well inclined section or horizontal section until the entire cutter is sent to the specified depth. After that, the traveling sub-joint stops working, and the anchor rotating sub-joint is controlled to start. First, the cutter is positioned at the current well depth, and then the cutting sub-joint is started. At the same time, the anchor rotating sub-joint drives the entire cutter to rotate at a constant speed and slowly, or at intervals, until The cutting sub joint completes the entire circumferential cutting operation on the pipe wall. Stop the cutting sub joint work, stop the anchoring rotating sub joint work, and recycle the cable at the wellhead.

It can be seen that the cutter of this application uses four pup joint combinations with different functions. Compared with the existing technology: (1) it can be sent into the underground pipeline by cable operation without being limited by the size of the feeding tool; In addition to conventional casing cutting, it can also meet the special cutting requirements for small-sized underground pipes such as oil pipes and drill pipes, significantly broadening the scope of application; (2) It abandons the traditional cutting technology of chemical explosion or chemical corrosion, and can The exact position of the tool in the well can be obtained through the length of the well cable, ensuring precise control of the cutting position and eliminating problems such as easy adhesion and formation contamination caused by chemical cutting methods; (3) Through the walking sub-joint and the centralizing sub-joint The cooperation of joints makes this application suitable for operations under various well inclinations and various well structures, such as highly inclined directional wells, extended reach wells, horizontal wells, and even wells that cannot be constructed by existing cable operations. The S-shaped unconventional well structure with reversely curved eye trajectory truly achieves the technical effect of cutting all types of underground pipes under various well structures.

The cutter is connected to a cable at the top, and the traveling sub-joint, centering sub-joint, anchoring rotating sub-joint and cutting sub-joint are all controlled and started by the cable. The top is the end of the cutter facing the wellhead after entering the well.

Further, the traveling sub-joint includes at least two traveling wheels rolling along the axial direction of the cutter, a first driving device for driving at least one traveling wheel to rotate, and a third driving device for driving all traveling wheels to retract and unfold in the radial direction. A diameter reducing mechanism.

Since the cutter of this application is a downhole tool, those skilled in the art should understand that the axial direction of the cutter and the axial direction of each sub-section in this application refer to the axial direction of the tool along the length direction, that is, after the tool is inserted into the well. Along the extension direction of the wellbore trajectory; and the radial direction in this application refers to the radial direction along the tool itself, that is, the radial direction along the wellbore after the tool is inserted into the wellbore.

This solution uses the first driving device to drive at least one running wheel to roll in the axial direction. The directly driven running wheel serves as the driving wheel. If there is a running wheel that is not directly driven, it serves as the driven wheel. Under the action of at least two running wheels, , so that this application has the ability to pass through obstruction points that conventional cable operations cannot pass, and to continue lowering to the required well depth in large well inclination sections and horizontal sections.

In addition, this solution uses the first diameter reducing mechanism to drive all the traveling wheels to retract and retract synchronously in the radial direction, so that the traveling sub-joint can adapt to downhole pipes of various inner diameter sizes to fully meet the needs of small-sized pipes such as drill pipes and oil pipes. Cable routing requirements within the column.

Among them, the driving of the rolling state of the running wheel by the first driving device and the adjustment of the radial position of the running wheel by the first diameter reducing mechanism can adopt any driving and transmission method that can be realized according to the existing technology, and are not limited here.

Further, the centralizing sub-joint includes a central shaft, a positioning member fixedly connected to the central shaft, a first sliding member and a second sliding member slidingly connected to the central shaft. The first sliding member is located at The first elastic member is connected between the positioning member and the second sliding member, and between the first sliding member and the second sliding member; it also includes a second driving device for driving the second sliding member to slide along the central axis, and a connection A plurality of second reducing mechanisms evenly distributed along the circumferential direction between the positioning member and the first sliding member. The maximum outer diameter of the second diameter reducing mechanism can be adjusted under the driving of the second driving device.

This solution limits the specific structure of the centralizing sub-joint. When the centralizing sub-joint is started, power is supplied to the second driving device. The second driving device drives the second sliding member to slide on the central axis, thereby causing the second diameter reducing mechanism to be squeezed. Press or stretch to adjust the maximum outer diameter of the second diameter reducing mechanism, so that the centering nipple can meet the centering needs of downhole pipelines with any inner diameter. Moreover, during the sliding process of the second sliding member, the first elastic member undergoes elastic deformation, so that when the centering sub-joint is not required to work, the second diameter reducing mechanism can automatically recover and reset. It can be seen that this solution has the ability to actively control the centralizing sub-joint. Compared with the traditional fixed or passive centralizing method, it not only significantly improves the versatility and adaptability, but also can be used when the cable is lowered. When blocking, the second diameter reducing mechanism is automatically contracted to improve the ability of the cutter to pass through the blocking section during cable operation. Of course, those skilled in the art should understand that downhole internal pipe blocking sections include, but are not limited to, casing shoe positions, pipe string coupling positions, unequal-diameter drilling tool connections, etc.

Further, the second diameter reducing mechanism includes a first link hinged with the positioning member and a second link hinged with the first slider. The first link and the second link are hinged with each other. ; It also includes a number of support wheels, which are arranged at the hinge of the first connecting rod and the second connecting rod; the first connecting rod and the second connecting rod are hinged with rockers, and there are several rocking rods on the central axis. chute, the long axis of the chute is parallel to the axis of the central axis, and the rocker is slidingly fitted in the chute.

This solution specifically limits the second diameter reducing mechanism. Through the mutual hinge of the first connecting rod and the second connecting rod, when the first sliding member is close to the positioning member, the gap between the first connecting rod and the second connecting rod is As the angle becomes smaller, the second diameter-reducing mechanism expands outward and the outer diameter increases; conversely, when the first sliding member moves away from the positioning member, the angle between the first connecting rod and the second connecting rod becomes larger, and the second diameter-reducing mechanism The mechanism shrinks inward and the outer diameter decreases. In addition, in order to prevent the first link and the second link from bending inward, this solution is specially equipped with a rocker, which restricts the rocker to only slide in a straight line along the chute, thus preventing the first link and the second link from bending. The rod is bent inward to ensure that the second reducing mechanism of the present application can always be bent and expanded outward, so that the support wheel located at the hinge of the two connecting rods can contact the pipe wall to achieve the support and centering effect, and make the present invention During the process of entering the well, the support wheel can also be in contact with the pipe wall to reduce wear on the tool body.

In addition to being arranged at the hinge of the first link and the second link, the support wheel in this solution can also be arranged at other positions as needed.

Further, the anchor rotating sub-joint includes at least two anchor wheels rolling along the circumferential direction of the cutter, a third driving device for driving at least one anchor wheel to rotate, and a third driving device for driving all anchor wheels to retract and retract in the radial direction. The third diameter reducing mechanism; the anchor wheel includes a large diameter wheel and a small diameter wheel, and the diameter of the large diameter wheel is larger than the diameter of the small diameter wheel.

In the field of oil drilling and production, existing technologies generally use slip structures to temporarily anchor downhole tools. Since traditional cable operations cannot drive the tools in the well to rotate, and slips cannot be rotated after they are fixed, existing slip structures are used. The anchoring structure is completely unable to realize the rotation of the cutter in the well, which results in the entire circumferential cutting operation of the pipeline completely relying on the cutting mechanism itself to complete the entire circumferential rotation around the inner wall of the pipeline, resulting in a very complex driving structure of the cutting structure; and during the cutting process High-frequency vibrations can easily cause abnormal accidents in these complex drive structures. They have a low service life and are not suitable for segmented operations requiring multiple cuttings into the well at one time. This application adopts an anchor rotating sub-joint with both axial positioning and circumferential rotation to overcome this defect. There are at least two anchor wheels to ensure stable rolling on the pipe wall, and at least one anchor wheel is driven by a third driving device. Rotate, so that the directly driven anchor wheel acts as the driving wheel, and if there is an anchor wheel that is not directly driven, it acts as the driven wheel, causing the anchor rotating sub-joint to rotate axially on the pipe wall, thereby driving the entire cutter, especially the cutting short joint. The joints rotate to overcome the shortcomings of the existing cable operation and slip anchoring methods that cannot rotate. The anchoring in this solution is achieved through the friction between the anchor wheels and the pipe wall. Through the outward expansion of the third diameter reducing mechanism, the pressure between each anchor wheel and the pipe wall is in a larger state, thereby making the anchoring The friction between the wheel and the pipe wall is in a large state, so that the entire tool can be temporarily anchored under the specified well depth. It should be noted that the anchorage in this application is not the anchorage of slip mounts in the traditional sense, but remains relatively stable at the depth of the designated well without shaking or deflection.

The anchored rotating sub-joint of this solution is also particularly suitable for use in highly deviated wells, extended reach wells and horizontal well sections. Conventional wireline operations simply cannot send the tool into these well sections, and even if it is successfully sent, since the gravity of the tool in these well sections is almost completely borne by the pipe wall, the cable cannot be tensioned (if it is forcibly tensioned, it will easily lead to Tool displacement), so the axial stability of the tool in the well cannot be guaranteed. However, the anchored rotating sub of this solution can fully overcome this defect.

Among them, the driving of the rotation state of the anchor wheel by the third driving device and the adjustment of the radial position of each anchor wheel of the third diameter reducing mechanism can adopt any driving and transmission method that can be realized according to the existing technology, and are not limited here.

In addition, in this solution, the anchor wheels include at least two different outer diameter sizes: a large diameter wheel and a small diameter wheel. Since all anchor wheels are retracted and reduced in diameter simultaneously, the large diameter wheel and the small diameter wheel are in the third diameter reducing mechanism. Under the action, it is also retracted and opened synchronously in the radial direction, taking advantage of the particularity of its unequal outer diameter, so that the anchor rotating sub-joint is in an eccentric state in the pipe to be cut, and then drives the entire cutter to be in an eccentric state, which is conducive to the alignment of the cutting sub-joint. Cutting of pipe walls, especially for downhole conditions with double-layer piping systems (such as double-layer pipes with oil casing annulus, double-layer pipes with drill casing annulus, overlapping portions of casing in adjacent well sections) Double-layer pipe), compared with the conventional cutting method that only moves the cutting blade eccentrically, it significantly expands the eccentric cutting range and improves the adaptability to various working conditions.

Further, the output end of the third driving device drives the transmission wheel to rotate, and the large-diameter wheel and the transmission wheel are driven by a chain or a synchronous belt; a tensioning mechanism for tensioning the chain or the synchronous belt is also included. .

This solution uses the third driving device to drive the transmission wheel to rotate, and then the chain or synchronous belt drives the large-diameter wheel to rotate synchronously to realize the rotation function of the anchor rotating sub-section. The large-diameter wheel in this solution serves as the driving roller in the anchored rotating sub-joint. The tensioning mechanism is used to keep the chain or synchronous belt in a tensioned state at all times. Its specific tensioning method is not limited here, and any tensioning method that can be achieved through existing technology is applicable.

Further, the third diameter reducing mechanism includes a main shaft, a third sliding member slidingly fitted on the main shaft, a fourth driving device for driving the third sliding member to slide along the main shaft, and a third sliding member sleeved on the main shaft. A second elastic member on the main shaft, at least two plug-in parts distributed evenly on the main shaft in the circumferential direction, and a fourth sliding member that slides and fits with the plug-in parts in the radial direction; one end of the second elastic member is opposite to the main shaft. The other end is fixed and in contact with the third sliding member; the fourth sliding member is connected to the anchor wheel in one-to-one correspondence;

It also includes a third link hinged on the plug-in part, a fourth link hinged on the fourth slider, and a fifth link hinged on the third slider. The third link is connected to the corresponding third link. The four connecting rods are hinged to each other, and the fifth connecting rod is hinged to the fourth connecting rod.

This plan limits the specific structure of the third diameter reducing mechanism. When each anchor wheel needs to be retracted and retracted in the radial direction, the fourth driving device is controlled to start, driving the third sliding member to slide on the main shaft, and driving the fifth connecting rod to move. , the fifth connecting rod pushes the fourth connecting rod to move, and at the same time makes the third connecting rod follow the movement, finally causing the fourth sliding member to slide in the radial direction in the insertion part, and then drives the anchor wheel to adjust the radial position.

It should be noted that since the anchor wheel has two different sizes: a large diameter wheel and a small diameter wheel, the length of the fifth connecting rod corresponding to the anchor wheel of different sizes should be different, that is, the length of the fifth connecting rod corresponding to the small diameter wheel , should be greater than the length of the fifth connecting rod corresponding to the large diameter wheel. Its specific length is not limited here. It can be set adaptively according to the actual size of each connecting rod to ensure that all anchor wheels can contact the inner wall of the pipe at the same time. .

Further, the anchoring rotating sub also includes a first housing; the centers of all anchoring wheels are distributed around a circle, and the circle is distributed eccentrically within the first housing.

This solution makes the centers of all the anchoring wheels on the same circle, and makes the circle moderately eccentric with respect to the first housing, thereby further improving the eccentricity capability of the application, further expanding the eccentric cutting range, and improving the accuracy of various work processes. ability to adapt to circumstances.

Further, the cutting nipple includes a second housing, a cutting knife located at the bottom of the second housing, a fifth driving device for driving the cutting knife to rotate, and a fifth driving device for driving the cutting knife to move in the radial direction. Linear adjustment mechanism; the cutter is eccentrically distributed relative to the second housing.

In this solution, the fifth driving device drives the cutter to rotate to achieve the cutting function of the pipe wall; the radial position of the cutter is adjusted through a linear adjustment mechanism, thereby controlling the eccentricity of the cutter relative to the second housing, which is more beneficial Expand the eccentric cutting range and improve the adaptability to various double-layer pipe working conditions and even multi-layer pipe working conditions. Among them, the driving of the fifth driving device to rotate the cutter and the adjustment of the radial position of the cutter by the linear adjustment mechanism can be realized by using the existing rotary drive or linear drive methods, which are not limited here.

In this solution, the cutter only rotates around its own axis relative to the second housing. During the cutting process, the second housing and the cutter jointly rotate with the anchor rotating sub-joint to adjust the orientation and realize the pipe cutting. Compared with the existing technology, which relies entirely on designing complex cyclic operating trajectories for the cutting blade, effective cutting throughout the entire cycle significantly reduces control difficulty and is more conducive to improving cutting accuracy.

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

1. An oil and gas production pipe string cutter of the present invention can be fed into downhole pipes by cable operation without being limited by the size of the feeding tool. In addition to conventional casing cutting, it can also meet the needs of downhole cutting of oil pipes, drill pipes, etc. The special cutting operation requirements of small-sized pipes have significantly broadened the scope of application; at the same time, the traditional cutting technology of chemical explosion or chemical corrosion has been abandoned. The accurate position of the tool in the well can be obtained through the length of the well cable, ensuring the accurate position of the cutting position. Precise control, and eliminates the problems of easy adhesion and contamination of the formation caused by chemical cutting methods.

2. An oil and gas production pipe string cutter of the present invention can be applied to operations under various well inclinations and various well structures, such as highly inclined directional wells, extended reach wells, etc. that cannot be constructed by existing cable operations. Horizontal wells and even S-shaped unconventional wellbore structures with reversely curved wellbore trajectories truly achieve the technical effect of cutting all types of downhole pipes under various wellbore structures.

3. An oil and gas production pipe string cutter of the present invention has the ability to actively control the centralizing sub-joints. Compared with the traditional fixed or passive centralizing methods, it not only significantly improves the versatility and adaptability, but also significantly improves the versatility and adaptability. It can also actively contract the second diameter reducing mechanism when the cable is lowered and encounters obstacles, thereby improving the ability of the cutter to pass through the blocked section during cable operation.

4. In an oil and gas production pipe string cutter of the present invention, the anchoring rotating sub-joint is anchored through the friction between the anchor wheel and the pipe wall. Through the outward expansion of the third diameter reducing mechanism, each anchor wheel can be connected to the pipe wall. The pressure between the two is in a large state, so that the friction between the anchor wheel and the pipe wall is in a large state, thereby achieving temporary anchoring of the entire tool at the specified well depth. In addition, the anchored rotating sub-joint can also meet the requirements for operations in highly deviated wells, extended reach wells and horizontal well sections.

5. An oil and gas production pipe string cutter of the present invention uses a variety of technical means to make the cutter actively eccentric. Compared with the conventional cutting method that only moves the cutting blade eccentrically, it is more suitable for double-layer or even multi-layer cutting. The working conditions of underground pipelines have significantly expanded the eccentric cutting range and improved the adaptability to various working conditions.

Description of drawings

The drawings described here 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 to the embodiments of the present invention. In the attached picture:

Figure 1 is a front view of a specific embodiment of the present invention;

Figure 2 is a schematic structural diagram of a walking sub-joint in a specific embodiment of the present invention;

Figure 3 is an internal schematic diagram of the traveling sub-joint in a specific embodiment of the present invention;

Figure 4 is a schematic structural diagram of a centralizing sub-joint in a specific embodiment of the present invention;

Figure 5 is an internal schematic diagram of the centralizing sub-joint in a specific embodiment of the present invention;

Figure 6 is a schematic structural diagram of the central axis in a specific embodiment of the present invention;

Figure 7 is a schematic structural diagram of an anchoring rotating sub-joint in a specific embodiment of the present invention;

Figure 8 is an internal schematic diagram of the anchoring rotating sub-joint in a specific embodiment of the present invention;

Figure 9 is a schematic structural diagram of the tensioning mechanism in a specific embodiment of the present invention;

Figure 10 is a schematic structural diagram of a cutting nipple in a specific embodiment of the present invention;

Figure 11 is an internal schematic diagram of the cutting nipple in a specific embodiment of the present invention;

Figure 12 is a schematic structural diagram of a specific embodiment of the present invention.

Marks and corresponding parts names in the attached drawings:

1-traveling sub-joint, 101-traveling wheel, 102-first driving device, 103-first hydraulic push rod, 104-push block, 105-crawling connecting rod, 2-righting sub-joint, 201-central shaft, 202- Positioning member, 203-first sliding member, 204-second sliding member, 205-first elastic member, 206-second driving device, 207-first connecting rod, 208-second connecting rod, 209-support wheel, 210-rocker, 211-slide, 3-anchored rotating sub-joint, 301-third drive device, 302-large diameter wheel, 303-small diameter wheel, 304-transmission wheel, 305-main shaft, 306-third sliding member , 307-Fourth driving device, 308-Second elastic member, 309-Insertion part, 310-Fourth sliding member, 311-Third connecting rod, 312-Fourth connecting rod, 313-Fifth connecting rod, 314 -First housing, 315-sprocket, 316-support bar, 317-fifth sliding member, 318-mounting column, 319-limiting block, 320-fourth elastic member, 321-third elastic member, 4- Cutting nipple, 401-second housing, 402-cutting knife, 403-fifth driving device, 404-hydraulic motor, 405-turntable, 406-motor base, 407-sliding block, 408-fifth elastic member, 409 -Support rod.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below in conjunction with the examples and drawings. The schematic embodiments of the present invention and their descriptions are only used to explain the present invention and do not as a limitation of the invention. In the description of this application, it should be understood that the terms "front", "rear", "left", "right", "upper", "lower", "vertical", "horizontal", "high", The orientations or positional relationships indicated by "low", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying the device referred to. Or the elements must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be construed as limiting the scope of the present application.

Example 1:

An oil and gas production pipe string cutter, as shown in Figure 1, includes a traveling sub-section 1, a centering sub-section 2, an anchoring rotating sub-section 3 and a cutting sub-section 4;

When the walking sub-joint 1 is started, the cutter moves axially in the pipe;

When the centralizing nipple 2 is started, the cutter is centered in the pipe;

When the anchor rotating nipple 3 is started, the cutter maintains the current well depth and rotates around the pipeline axis;

The cutting nipple 4 cuts the pipe wall when started.

The cutter is connected to a cable at the top, and the traveling sub-joint 1, the centering sub-joint 2, the anchoring rotating sub-joint 3 and the cutting sub-joint 4 are all controlled and started by the cable.

In this embodiment, along the direction of the tool entering the well, the walking sub-joint 1, the centering sub-joint 2, the anchoring rotating sub-joint 3 and the cutting sub-joint 4 are distributed from top to bottom in order, and there are threads between two adjacent sub-joints. connect.

Example 2:

An oil and gas production pipe string cutter. Based on Embodiment 1, the traveling sub-joint, as shown in Figures 2 and 3, includes at least two traveling wheels 101 rolling along the axial direction of the cutter, and is used to drive at least A first driving device 102 for rotating the running wheels 101 and a first reducing mechanism for driving all the running wheels 101 to retract and unfold in the radial direction.

In this embodiment, the traveling sub-joint has a shell with holes for the running wheels to extend out; there are two running wheels 101, relatively distributed on both sides of the shell.

In this embodiment, the first driving device 102 is a motor, and its output end drives the two running wheels 101 to rotate synchronously and in the same direction through a gear set and a chain mechanism.

In a more preferred embodiment, the first diameter reducing mechanism includes a first hydraulic push rod 103 and a push block 104 connected to the output end of the first hydraulic push rod 103. Each traveling wheel 101 is hinged with a crawling link 105. And all crawling links 105 are hinged at the same position on the push block 104 .

Example 3:

An oil and gas production pipe string cutter. Based on Embodiment 1 or 2, the centralizing sub-joint is shown in Figures 4 and 5 and includes a central shaft 201 and a positioning member fixedly connected to the central shaft 201. 202. The first sliding member 203 and the second sliding member 204 are slidingly connected on the central shaft 201. The first sliding member 203 is located between the positioning member 202 and the second sliding member 204, and the first sliding member 203 The first elastic member 205 is connected to the second sliding member 204; it also includes a second driving device 206 for driving the second sliding member 204 to slide along the central axis 201, and a second driving device 206 connected to the positioning member 202 and the first sliding member 203. There are a number of second reducing mechanisms evenly distributed along the circumferential direction.

The central axis 201 in this embodiment is shown in Figure 6 .

The second diameter reducing mechanism includes a first link 207 hinged with the positioning member 202 and a second link 208 hinged with the first sliding member 203. The first link 207 and the second link 208 are hinged to each other; it also includes a number of support wheels 209, which are arranged at the hinge of the first connecting rod 207 and the second connecting rod 208; the first connecting rod 207 and the second connecting rod 208 are both hinged and rocking. The rod 210 has a plurality of chute 211 on the central shaft 201. The long axis of the chute 211 is parallel to the axis of the central shaft 201. The rocker 210 is slidably fitted in the chute 211.

In this embodiment, the centralizing sub-joint has a shell with holes for each support wheel to extend; the second driving device 206 is a hydraulic push rod, and the first elastic member 205 is a spring that is always in a stretched state.

In addition to being provided at the hinge of the first link 207 and the second link 208 , the support wheel 209 is also provided independently on the first link 207 and the second link 208 .

For any set of first connecting rods 207 and second connecting rods 208 that cooperate with each other, the angle between them is always an obtuse angle, and the obtuse angle faces inward.

In this embodiment, there are four sets of first connecting rods 207 and second connecting rods 208 that cooperate with each other, so there are four sets of supporting wheels 209 in total. Therefore, the chute 211 provided on the central shaft 201 is also four sets, evenly distributed along the circumferential direction; For any two adjacent groups of first connecting rods 207 and second connecting rods 208, the axes of the supporting wheels thereon are perpendicular to each other.

In addition, the two rockers 210 on the first link 207 and the second link 208 that are hinged to each other are slidingly fitted in the same chute. When the two rockers 210 contact each other, the corresponding first link 207 and the second connecting rod 208 still maintain an obtuse inward angle.

Example 4:

An oil and gas production pipe string cutter. Based on any of the above embodiments, the anchor rotating sub-joint, as shown in Figures 7 and 8, includes at least two anchor wheels rolling along the circumferential direction of the cutter. A third driving device 301 that drives at least one anchor wheel to rotate, and a third reducing mechanism that drives all anchor wheels to retract and expand in the radial direction; the anchor wheels include a large diameter wheel 302 and a small diameter wheel 303. The diameter of the wheel 302 is larger than the diameter of the small diameter wheel 303 .

The output end of the third driving device 301 drives the transmission wheel 304 to rotate, and the large-diameter wheel 302 and the transmission wheel 304 are driven by a chain; a tensioning mechanism for tensioning the chain is also included.

In this embodiment, the third driving device 301 is a motor, the output end of which drives the chain to rotate through the gear set, and then the chain drives the large-diameter wheel 302 to rotate.

The third diameter reducing mechanism in this embodiment includes a main shaft 305, a third sliding member 306 slidingly fitted on the main shaft 305, a fourth driving device 307 for driving the third sliding member 306 to slide along the main shaft 305, The second elastic member 308 is sleeved on the main shaft 305, at least two plug-in parts 309 evenly distributed on the main shaft 305 in the circumferential direction, and the fourth sliding member 310 is slidably matched with the plug-in part 309 in the radial direction. ; One end of the second elastic member 308 is relatively fixed to the main shaft 305, and the other end is in contact with the third sliding member 306; the fourth sliding member 310 is connected to the anchor wheel in a one-to-one correspondence;

It also includes a third link 311 hinged on the insertion part 309, a fourth link 312 hinged on the fourth sliding member 310, and a fifth link 313 hinged on the third sliding member 306. The connecting rod 311 is hingedly connected to the corresponding fourth connecting rod 312, and the fifth connecting rod 313 is hingedly connected to the fourth connecting rod 312.

The anchoring rotating nipple 3 also includes a first housing 314; the centers of all anchoring wheels are distributed around a circle, and the circle is distributed eccentrically within the first housing 314.

In this embodiment, the fourth driving device 307 is a hydraulic push rod, and the second elastic member 308 is a spring that is always in a compressed state.

Since the anchor wheel has two different sizes: a large diameter wheel and a small diameter wheel, the length of the fifth connecting rod corresponding to the anchor wheel of different sizes should be different, that is, the length of the fifth connecting rod corresponding to the small diameter wheel should be larger than that of the large diameter wheel. The length of the fifth link corresponding to the wheel. In this embodiment, when the fourth driving device 307 drives the third sliding member 306 to return to the upper end of the stroke, all the fourth sliding members 310 are in a state of contact with the sockets of the respective plug-in portions 309 .

In a more preferred embodiment, the fifth link 313 has a hollow structure, so that the third link 311 passes through the hollow part of the fifth link 313 .

In a more preferred embodiment, the tensioning mechanism, as shown in Figure 9, includes two sprockets 315 meshed with the chain, a support bar 316 connected to the end of the main shaft 305, and a sliding fitting on the support. Fifth sliding parts 317 at both ends of the strip 316. The sliding direction of the fifth sliding part 317 is parallel to the line connecting the centers of the two sprockets 315, and the two sprockets 315 are respectively installed on the fifth sliding parts 317 on both sides. ; It also includes a mounting post 318 fixed on the fifth sliding member 317 and a limit block 319 located in the middle of the support bar 316. A number of third elastic members 321 are connected between the mounting posts 318 on both sides. The fourth elastic member 320 is connected between the sliding member 317 and the limiting block 319 .

Preferably, the third elastic member 321 is a spring that is always in a tensile state, and the fourth elastic member 320 is a spring that is always in a compressed state.

Through the setting of this kind of tensioning mechanism, the chain can always be automatically kept in a tensioned state when adjusting the radial position of each anchor wheel.

Example 5:

An oil and gas production pipe string cutter. Based on any of the above embodiments, the cutting sub-joint, as shown in Figures 10 and 11, includes a second housing 401 and a cutting knife located at the bottom of the second housing 401. 402. The fifth driving device 403 for driving the cutting knife 402 to rotate, and the linear adjustment mechanism for driving the cutting knife 402 to move in the radial direction; the linear adjustment mechanism makes the cutting knife 402 relative to the second housing 401 Eccentric distribution.

In this embodiment, the fifth driving device 403 is a motor, and its output end directly or indirectly drives the cutting knife 402 to rotate.

In a more preferred embodiment, the linear adjustment mechanism includes a hydraulic motor 404, and the output end drives the turntable 405 to rotate through a transmission mechanism. A spiral groove is provided on the turntable 405. The fifth driving device 403 is installed on the motor base 406. A slide block 407 is fixedly connected to the seat 406, and the slide block 407 is slidably fitted in the spiral groove.

The hydraulic motor 404 drives the turntable to rotate, causing the spiral groove to rotate. The spiral groove and the slider 407 move relative to each other, causing the motor base 406 and the fifth driving device 403 located on the motor base 406 to move synchronously in the radial direction, thereby changing the direction of the cutting knife 402. radial position.

In a more preferred embodiment, a fifth elastic member 408 is also included. One end of the fifth elastic member 408 is sleeved on the motor base 406 and the other end is in contact with the inner wall of the second housing 401 . Preferably, the fifth elastic member 408 is a spring that is always in a compressed state.

In a more preferred embodiment, a support rod 409 is also included. One end of the support rod 409 is hinged on the motor base 406 and the other end is in contact with the inner wall of the second housing 401 . When adjusting the radial position of the cutter 402, the support rod 409 automatically rotates under the action of gravity, and can always maintain contact with the pipe wall as long as the size is satisfied, thereby playing a supporting role.

Example 6:

An oil and gas production pipe string cutter. Based on any of the above embodiments, as shown in Figure 12, the pipe wall cutter of this embodiment includes a traveling sub-joint 1 and a centralizing sub-joint 2 connected in sequence from top to bottom. , anchoring rotating sub-joint 3, traveling sub-joint 1, centering sub-joint 2, anchoring rotating sub-joint 3, cutting sub-joint 4. That is, this embodiment includes two traveling sub-joints 1, two centering sub-joints 2 and two anchoring rotating sub-joints 3. This structure can significantly improve the stability and stability of the cutter being sent into the well by wireline operation to the required position. It has high reliability and a certain ability to block jams and get out of trouble, which can significantly improve project safety and reduce the risk of accidents in cable operations.

In a more preferred embodiment, the traveling wheels 101 in the two sets of traveling sub-joints 1 are staggered in the circumferential direction, thereby further ensuring stable traveling in highly inclined directional wells, large displacement wells, and horizontal well sections.

The above-described specific embodiments further describe the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above-mentioned are only specific embodiments of the present invention and are not intended to limit the scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that these entities or operations are mutually exclusive. any such actual relationship or sequence exists between them. Furthermore, the terms "comprises," "comprises," or any other variations thereof, are intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also elements not expressly listed or other elements inherent in the process, method, article or equipment. In addition, the term "connection" used in this article may be a direct connection or an indirect connection through other components unless otherwise specified.

Claims (7)

1. The oil and gas production pipe column cutter is characterized by comprising a walking nipple (1), a righting nipple (2), an anchoring rotary nipple (3) and a cutting nipple (4);

when the walking pup joint (1) is started, the cutter axially walks in the pipeline;

centering the cutter in the pipeline when the centering pup joint (2) is started;

when the anchoring rotary pup joint (3) is started, the cutter keeps the current well depth and rotates around the axis of the pipeline;

the pipe wall is cut when the cutting pup joint (4) is started;

the anchoring rotary pup joint (3) comprises at least two anchoring wheels rolling along the circumferential direction of the cutter, a third driving device (301) for driving at least one anchoring wheel to rotate, and a third reducing mechanism for driving all the anchoring wheels to retract along the radial direction; the anchoring wheel comprises a large diameter wheel (302) and a small diameter wheel (303), and the diameter of the large diameter wheel (302) is larger than that of the small diameter wheel (303);

the output end of the third driving device (301) drives the driving wheel (304) to rotate, and the large-diameter wheel (302) and the driving wheel (304) are driven by a chain or a synchronous belt; the device also comprises a tensioning mechanism for tensioning the chain or the synchronous belt;

the third reducing mechanism comprises a main shaft (305), a third sliding part (306) which is in sliding fit with the main shaft (305), a fourth driving device (307) which is used for driving the third sliding part (306) to slide along the main shaft (305), a second elastic part (308) which is sleeved on the main shaft (305), at least two plug-in parts (309) which are circumferentially distributed on the main shaft (305) and a fourth sliding part (310) which is in sliding fit with the plug-in parts (309) along the radial direction; one end of the second elastic piece (308) is relatively fixed with the main shaft (305), and the other end of the second elastic piece is abutted with the third sliding piece (306); the fourth sliding parts (310) are correspondingly connected with the anchoring wheels one by one;

the device further comprises a third connecting rod (311) hinged on the plug-in part (309), a fourth connecting rod (312) hinged on the fourth sliding piece (310) and a fifth connecting rod (313) hinged on the third sliding piece (306), wherein the third connecting rod (311) is hinged with the corresponding fourth connecting rod (312), and the fifth connecting rod (313) is hinged with the fourth connecting rod (312);

the second elastic piece (308) is a spring which is always in a compressed state; the length of the fifth connecting rod corresponding to the small diameter wheel is longer than that of the fifth connecting rod corresponding to the large diameter wheel; when the fourth driving device (307) drives the third sliding piece (306) to return to the upper end of the stroke, all the fourth sliding pieces (310) are in abutting state with the sockets of the corresponding plug-in parts (309).

2. An oil and gas production string cutter according to claim 1, characterized in that the cutter connects the cable at the top, and the traveling nipple (1), the centralizing nipple (2), the anchoring rotary nipple (3) and the cutting nipple (4) are all activated by the cable control.

3. An oil and gas production string cutter according to claim 1, wherein the travelling nipple (1) comprises at least two travelling wheels (101) rolling along the axial direction of the cutter, a first driving device (102) for driving at least one travelling wheel (101) to rotate, and a first reducing mechanism for driving all travelling wheels (101) to retract in the radial direction.

4. An oil and gas production string cutter according to claim 1, wherein the centralizing sub (2) comprises a central shaft (201), a positioning member (202) fixedly connected to the central shaft (201), a first sliding member (203) and a second sliding member (204) slidingly connected to the central shaft (201), the first sliding member (203) is located between the positioning member (202) and the second sliding member (204), and a first elastic member (205) is connected between the first sliding member (203) and the second sliding member (204); the device also comprises a second driving device (206) for driving the second sliding piece (204) to slide along the central shaft (201), and a plurality of second reducing mechanisms which are connected between the positioning piece (202) and the first sliding piece (203) and uniformly distributed along the circumferential direction.

5. The oil and gas production string cutter of claim 4, wherein the second reducing mechanism comprises a first link (207) hinged to the positioning member (202), a second link (208) hinged to the first sliding member (203), and the first link (207) and the second link (208) are hinged to each other; the device also comprises a plurality of supporting wheels (209), wherein the supporting wheels (209) are arranged at the hinge joint of the first connecting rod (207) and the second connecting rod (208); the first connecting rod (207) and the second connecting rod (208) are both hinged with a rocker (210), the central shaft (201) is provided with a plurality of sliding grooves (211), the long axis of each sliding groove (211) is parallel to the axis of the central shaft (201), and the rocker (210) is in sliding fit in each sliding groove (211).

6. An oil and gas production string cutter as claimed in claim 1, wherein the anchor rotary nipple (3) further comprises a first housing (314); the centers of all the anchor wheels are distributed around a circumference, and the circumference is eccentrically distributed in the first housing (314).

7. An oil and gas production string cutter according to claim 1, wherein the cutting nipple (4) comprises a second housing (401), a cutter (402) arranged at the bottom of the second housing (401), a fifth driving device (403) for driving the cutter (402) to rotate, and a linear adjusting mechanism for driving the cutter (402) to move radially; the cutters (402) are distributed eccentrically relative to the second housing (401).