Hydraulic internal cutting knife and method for cutting single-layer solid expansion casing

Abstract

According to the hydraulic internal cutting knife and method for cutting the single-layer solid expansion casing, in the hydraulic internal cutting knife, a cutting knife body is of a tubular structure with a hollow channel, a plurality of blades are evenly distributed on the cutting knife body on the circumference, and a blade pushing hydraulic cylinder is movably arranged on the cutting knife body in a sleeving mode and is in threaded connection with a blade supporting body to drive the blade supporting body; the blade pushing hydraulic cylinder is communicated with the hollow channel, the supporting sleeve is arranged between the upper cone connecting sleeve and the cutting knife body, the supporting sleeve is fixedly connected with the cutting knife body, and a plurality of steel balls are arranged between the supporting sleeve and the upper cone connecting sleeve; the central pipe is in threaded connection with the inner wall of the upper cone and communicates with the hollow channel; the plurality of slips are sleeved on the central pipe and are uniformly distributed in the circumferential direction, and the slips are arranged between the upper cone and the lower cone and can extend outwards in the radial direction; the lower cone pushing hydraulic cylinder is movably arranged on the central pipe in a sleeving mode, fixedly connected with the lower cone and communicated with the hollow pipe. The hydraulic internal cutting knife can accurately cut a single-layer expansion casing pipe.

Description

Technical Field

[0001] The present invention relates to the technical field of workover operations, and particularly to a hydraulic internal cutter and method for cutting a single-layer solid expandable casing. Background Art

[0002] The expandable casing patch technology has the advantages of high pressure resistance, large internal diameter, good high temperature resistance and strong anchoring ability, and is widely used in various types of casing damage repair, high water-bearing layer plugging and perforated well section plugging. Due to the failure of the downhole expandable casing or other technological measures, it is required to first cut the expandable casing in sections and then salvage the pipe body one by one. After the expandable casing is patched, it clings tightly to the outer layer of the completion casing, and the annular clearance is extremely small, only 1-2 mm, which brings the following two difficulties to the cutting of the expandable casing: (1) The tool size is small, the cutting depth of the hydraulic cutter is small, and the expandable casing cannot be cut thoroughly, resulting in difficulties in subsequent pipe body salvage; (2) The tool size is large, the cutting depth of the hydraulic cutter is too large, and it is easy to accidentally cut the completion casing outside the expandable casing, resulting in new casing damage in the oil well.

[0003] Shale oil and gas wells have extremely high requirements for wellbore integrity, requiring the hydraulic cutter to have precise cutting ability and not to cause a serious accident of accidentally cutting the completion casing, which complicates the wellbore treatment. The existing casing cutter technology has the following three problems: The cutter tool has no limit mechanism, and it is difficult to accurately control the maximum cutting outer diameter of the cutter head, and there is a risk of accidentally cutting the outer casing. The cutter tool has no anchoring mechanism and cannot be anchored to the inner wall of the casing. The cutting string moves up and down, resulting in a change in the up and down position of the cutter, low cutting efficiency, and easy breakage of the cutter blade. The cutter tool has no blade reset mechanism. After the casing is cut, the cutter cannot be retracted smoothly, and there is a risk of jamming.

[0004] The above information disclosed in the background art section is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0005] The purpose of the present invention is to provide a hydraulic internal cutter and method for cutting a single-layer solid expandable casing, solve the problem of precise cutting of the single-layer expandable casing, and not damage the outer completion casing, providing a good working condition for the salvage of the expandable casing and subsequent secondary patching and casing repair.

[0006] In order to achieve the above purpose, the present invention provides the following technical solutions:

[0007] A hydraulic internal cutter for cutting a single-layer solid expandable casing of the present invention includes:

[0008] A cutter body, which is a tubular structure with a hollow channel, and the cutter body is provided with a groove in the circumferential direction;

[0009] Multiple blades, which are evenly distributed on the circumference of the cutter body, and the blades are rotatably arranged in the grooves;

[0010] A blade support body, which is movably sleeved on the cutter body to abut against or away from the blade;

[0011] A blade pushing hydraulic cylinder, which is movably sleeved on the cutter body and is threadedly connected to the blade support body to drive the blade support body, and the blade pushing hydraulic cylinder communicates with the hollow channel;

[0012] A blade return spring, which is sleeved between the cutter body and the blade pushing hydraulic cylinder;

[0013] An upper cone connecting sleeve, which is sleeved on the cutter body, and the top end of the upper cone connecting sleeve extends between the blade pushing hydraulic cylinder and the cutter body;

[0014] An upper cone, which is threadedly connected to the upper cone connecting sleeve;

[0015] A support sleeve, which is arranged between the upper cone connecting sleeve and the cutter body, the support sleeve is fixedly connected to the cutter body, and a number of steel balls are arranged between the support sleeve and the upper cone connecting sleeve;

[0016] A central tube, which is threadedly connected to the inner wall of the upper cone, and the central tube communicates with the hollow channel;

[0017] A lower cone, which is movably sleeved on the central tube;

[0018] Multiple slips, which are sleeved on the central tube and are evenly distributed in the circumferential direction, and the slips are placed between the upper cone and the lower cone and can radially extend outwards;

[0019] A slip cover, which is sleeved outside the slips and the slip cover is fixedly connected to the upper cone connecting sleeve;

[0020] Multiple leaf springs, which are arranged between the slips and the slip cover;

[0021] A lower cone pushing hydraulic cylinder, which is movably sleeved on the central tube, and the lower cone pushing hydraulic cylinder is fixedly connected to the lower cone, and the lower cone pushing hydraulic cylinder communicates with the hollow tube;

[0022] A lower cone return spring, which is sleeved between the lower cone pushing hydraulic cylinder and the central tube;

[0023] A guide shoe, which is fixedly connected to the central tube, and the central tube communicates with the central tube.

[0024] In the described hydraulic internal cutter for cutting a single-layer solid expandable casing, liquid enters the blade pushing cylinder, the lower cone pushing cylinder, and the guide shoe respectively along the hollow channel. The throttling pressure pushes the lower cone pushing cylinder to move upward. The lower cone pushing cylinder squeezes the lower cone return spring upward, pushing the lower cone to move upward. Under the action of the upward force of the lower cone, the slips extend radially outward.

[0025] In the described hydraulic internal cutter for cutting a single-layer solid expandable casing, the throttling pressure pushes the blade pushing cylinder to move upward. The blade pushing cylinder squeezes the blade return spring upward, pushing the blade support body to move upward. The blade support body contacts the bottom end of the blade upward, propping up the tip of the blade. The cutter body is connected to the support sleeve and presses down on the support ball. The cutter body rotates with the support sleeve and the blade to cut layer by layer.

[0026] In the described hydraulic internal cutter for cutting a single-layer solid expandable casing, the blade is rotatably arranged in the groove via the first pin shaft. The first hexagon socket flat end set screw is fixedly connected to the blade. The blades are evenly distributed on the 360-degree circumference at an interval of 120 degrees.

[0027] In the described hydraulic internal cutter for cutting a single-layer solid expandable casing, the top end of the blade return spring is limited by the blade return spring retaining ring. The blade return spring retaining ring is fixed on the cutter body by threads and hexagon socket cone end set screws. The lower cone return spring retaining ring is sleeved between the lower cone pushing cylinder and the central tube and is located at the bottom end of the lower cone return spring. The lower cone return spring retaining ring connects and fixes the lower cone pushing cylinder by threads and hexagon socket cone end set screws.

[0028] In the described hydraulic internal cutter for cutting a single-layer solid expandable casing, the blade pushing cylinder and the cutter body are sealed by the first sealing ring. The upper cone connecting sleeve is sealed and connected to the blade pushing cylinder via the second sealing ring. The upper cone connecting sleeve is sealed and connected to the cutter body via the third sealing ring. The upper cone and the upper cone connecting sleeve are sealed by the fourth sealing ring. The upper cone and the cutter body are sealed by the fifth sealing ring. The central tube is sealed and connected to the upper cone via the sixth sealing ring. The lower cone pushing cylinder and the central tube are sealed by the seventh sealing ring.

[0029] In the described hydraulic internal cutter for cutting a single-layer solid expandable casing, the support sleeve fixes the cutter body by threads and the second hexagon socket cone end set screw. The lower cone pushing cylinder and the lower cone are connected by the second pin shaft and the second hexagon socket flat end set screw. The central tube and the guide shoe are connected and fixed by threads and the fourth hexagon socket cone end set screw.

[0030] In the described hydraulic internal cutter for cutting a single-layer solid expandable casing, 4 slips are evenly distributed on the 360° circumference at 90° intervals.

[0031] In the described hydraulic internal cutter for cutting a single-layer solid expandable casing, the slip cover is welded to the bottom end of the upper cone connecting sleeve, and the lower cone is limited in the downward movement direction via the slip cover.

[0032] The cutting method of the described hydraulic internal cutter for cutting a single-layer solid expandable casing includes the following steps.

[0033] The expandable casing is sleeved inside the completion casing. A plurality of sealing rubber cylinders are provided between the expandable casing and the completion casing. The hydraulic internal cutter is movably arranged inside the expandable casing.

[0034] Step 1: Pump in the workover fluid. The workover fluid enters the blade pushing cylinder, the lower cone pushing cylinder, and the guide shoe respectively along the hollow channel.

[0035] Step 2: The throttling pressure pushes the lower cone pushing cylinder to move upward. The lower cone pushing cylinder squeezes the lower cone return spring upward, pushing the lower cone to move upward. Under the upward force of the lower cone, the slips extend radially outward and are anchored on the inner wall of the expandable casing. The throttling pressure pushes the blade pushing cylinder to move upward. The blade pushing cylinder squeezes the blade return spring upward, pushing the blade support to move upward. The blade support body contacts the bottom end of the blade upward, propping up the tip of the blade and pressing it against the inner wall of the expandable casing. Press down the drill string. The cutter body is connected to the support sleeve and presses down on the support ball. At this time, rotate the drill string. The cutter body drives the support sleeve and the blade to rotate and cut the expandable casing layer by layer. By controlling the throttling pressure through the displacement, the tip of the blade is always in contact with the inner wall of the expandable casing for cutting. The expandable pipe is cut layer by layer by the blade. When the expandable casing is completely cut through, relieve the pressure. The lower cone pushing cylinder moves downward under the elastic force of the lower cone return spring, dragging the lower cone to move downward. The slips lose the support of the lower cone and, under the elastic force of the leaf spring, the slips reset radially and disengage from the anchoring position of the expandable casing. The blade pushing cylinder moves downward under the elastic force of the blade return spring, dragging the blade support body to move downward. The blade loses the effective support of the blade support body and resets and retracts into the cutter body. At this time, the entire cutter is completely out of contact with the inner wall of the expandable casing.

[0036] Step 3: Move the hydraulic internal cutter downward and repeat Step 2 to execute the segmented cutting procedure for each sealing rubber cylinder part until the entire expandable casing is completely cut into several sections, and the pipe cutting is completed.

[0037] In the above technical solution, a hydraulic internal cutter for cutting a single-layer solid expandable casing provided by the present invention has the following beneficial effects: it can accurately and thoroughly cut the expandable casing in sections, will not mistakenly cut the completion casing on the outer layer of the expandable casing, and will not complicate the wellbore treatment. The tool is highly matched with the downhole environment, easy to operate, economical and practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings.

[0039] Figure 1 It is a schematic structural diagram of a hydraulic internal cutter for cutting a single-layer solid expandable casing provided by an embodiment of the present invention.

[0040] Figure 2 It is a schematic structural diagram of a damaged original well completion casing, expandable casing and sealing rubber barrel of a hydraulic internal cutter for cutting a single-layer solid expandable casing provided by an embodiment of the present invention.

[0041] Figure 3 For Figure 1 It is a schematic structural diagram of the first section from top to bottom of a hydraulic internal cutter for cutting a single-layer solid expandable casing provided by an embodiment of the present invention.

[0042] Figure 4 For Figure 1 It is a schematic structural diagram of the second section from top to bottom of a hydraulic internal cutter for cutting a single-layer solid expandable casing provided by an embodiment of the present invention.

[0043] Figure 5 For Figure 1 It is a schematic structural diagram of the third section from top to bottom of a hydraulic internal cutter for cutting a single-layer solid expandable casing provided by an embodiment of the present invention.

[0044] Among them, the reference numerals are: 1. cutter body, 2. first pin shaft, 3. first hexagon socket flat end set screw, 4. blade, 5. blade support body, 6. blade return spring retaining ring, 7. first hexagon socket cone end set screw, 8. blade return spring, 9. blade pushing hydraulic cylinder, 10. first sealing ring, 11. second sealing ring, 12. third sealing ring, 13. upper cone connection sleeve, 14. second hexagon socket cone end set screw, 15. support sleeve, 16. steel ball, 17. fourth sealing ring, 18. fifth sealing ring, 19. upper cone, 20. sixth sealing ring, 21. slip cover, 22. leaf spring, 23. slip, 24. lower cone, 25. central tube, 26. second pin shaft, 27. second hexagon socket flat end set screw, 28. seventh sealing ring, 29. eighth sealing ring, 30. lower cone pushing hydraulic cylinder, 31. lower cone return spring, 32. third hexagon socket cone end set screw, 33. lower cone return spring retaining ring, 34. fourth hexagon socket cone end set screw, 35. guide shoe, 36. completion casing, 37. sealing rubber barrel, 38. expandable casing. Detailed implementation manners

[0045] To make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0046] Therefore, the detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0047] It should be noted that: like reference numerals and letters denote like items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0048] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings. It 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. Therefore, it should not be construed as a limitation to the present invention.

[0049] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, the meaning of "a plurality" is two or more unless otherwise specifically defined.

[0050] In the present invention, unless otherwise clearly specified and defined, terms such as "mounted", "connected", "connected to", "fixed" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0051] In the present invention, unless otherwise clearly specified and defined, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature has a higher horizontal height than the second feature. The first feature being "below", "under" and "beneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature has a lower horizontal height than the second feature.

[0052] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0053] See Figures 1-5 As shown, in one embodiment, a hydraulic internal cutter for cutting a single-layer solid expandable casing of the present invention includes

[0054] The cutter body 1 is a tubular structure with a hollow channel, and the cutter body 1 is provided with a groove in the circumferential direction;

[0055] A plurality of blades 4 are evenly distributed on the cutter body 1 in the circumferential direction, and the blades 4 are rotatably arranged in the grooves;

[0056] The blade support 5 is movably sleeved on the cutter body 1 to abut against the blade 4 or move away from the blade 4;

[0057] The blade pushing hydraulic cylinder 9 is movably sleeved on the cutter body 1 and is threadedly connected to the blade support 5 to drive the blade support 5, and the blade pushing hydraulic cylinder 9 communicates with the hollow channel;

[0058] The blade return spring 8 is sleeved between the cutter body 1 and the blade pushing hydraulic cylinder 9;

[0059] The upper cone connecting sleeve 13 is sleeved on the cutter body 1, and the top end of the upper cone connecting sleeve 13 extends between the blade pushing hydraulic cylinder 9 and the cutter body 1;

[0060] The upper cone 19 is threadedly connected to the upper cone connecting sleeve 13;

[0061] The support sleeve 15 is arranged between the upper cone connecting sleeve 13 and the cutter body 1, the support sleeve 15 is fixedly connected to the cutter body 1, and a plurality of steel balls 16 are arranged between the support sleeve 15 and the upper cone connecting sleeve 13;

[0062] The central tube 25 is threadedly connected to the inner wall of the upper cone 19, and the central tube 25 communicates with the hollow channel;

[0063] The lower cone 24 is movably sleeved on the central tube 25;

[0064] A plurality of slips 23 are sleeved on the central tube 25 and are evenly distributed in the circumferential direction. The slips 23 are placed between the upper cone 19 and the lower cone 24 and can radially extend outwards;

[0065] The slip cover 21 is sleeved outside the slips 23 and the slip cover 21 is fixedly connected to the upper cone connecting sleeve 13;

[0066] A plurality of leaf springs 22 are arranged between the slips 23 and the slip cover 21;

[0067] The lower cone pushing hydraulic cylinder 30 is movably sleeved on the central tube 25, and the lower cone pushing hydraulic cylinder 30 is fixedly connected to the lower cone 24. The lower cone pushing hydraulic cylinder 30 communicates with the hollow tube;

[0068] The lower cone return spring 31 is sleeved between the lower cone pushing hydraulic cylinder 30 and the central tube 25;

[0069] The guide shoe 35 is fixedly connected to the central tube 25, and the central tube 25 is communicated with the central tube 25.

[0070] In the preferred embodiment of a hydraulic internal cutter for cutting a single-layer solid expandable casing, the liquid enters the blade pushing hydraulic cylinder 9, the lower cone pushing hydraulic cylinder 30 and the guide shoe 35 along the hollow channel respectively. The throttling pressure pushes the lower cone pushing hydraulic cylinder 30 to move upward. The lower cone pushing hydraulic cylinder 30 squeezes the lower cone return spring 31 upward, pushing the lower cone 24 to move upward. Under the action of the upward force of the lower cone 24, the slips 23 extend radially outward.

[0071] In the preferred embodiment of a hydraulic internal cutter for cutting a single-layer solid expandable casing, the throttling pressure pushes the blade pushing hydraulic cylinder 9 to move upward. The blade pushing hydraulic cylinder 9 squeezes the blade return spring 8 upward, pushing the blade support 5 to move upward. The blade support 5 contacts the bottom end of the blade 4 upward, propping up the tip of the blade 4. The cutter body 1 is connected with the support sleeve 15 and presses down on the support ball. The cutter body 1 drives the support sleeve 15 and the blade 4 to rotate to cut layer by layer.

[0072] In the preferred embodiment of a hydraulic internal cutter for cutting a single-layer solid expandable casing, the blade 4 is rotatably arranged in the groove via the first pin shaft 2. The first hexagon socket flat end set screw 3 is fixedly connected to the blade 4. The blades 4 are evenly distributed on the 360-degree circumference at intervals of 120 degrees.

[0073] In the preferred embodiment of a hydraulic internal cutter for cutting a single-layer solid expandable casing, the top end of the blade return spring 8 is limited by the blade return spring retaining ring 6. The blade return spring retaining ring 6 is fixed on the cutter body 1 by threads and the first hexagon socket cone point set screw 7. The lower cone return spring retaining ring 33 is sleeved between the lower cone pushing hydraulic cylinder 30 and the central tube 25 and is located at the bottom end of the lower cone return spring 31. The lower cone return spring retaining ring 33 is connected and fixed to the lower cone pushing hydraulic cylinder 30 by threads and the third hexagon socket cone point set screw 32.

[0074] In a preferred embodiment of the described hydraulic internal cutter for cutting a single-layer solid expandable casing, the blade pushing cylinder 9 and the cutter body 1 are sealed by a first sealing ring 10. The upper cone connecting sleeve 13 is hermetically connected to the blade pushing cylinder 9 via a second sealing ring 11. The upper cone connecting sleeve 13 is hermetically connected to the cutter body 1 via a third sealing ring 12. The upper cone 19 and the upper cone connecting sleeve 13 are sealed by a fourth sealing ring 17. The upper cone 19 and the cutter body 1 are sealed by a fifth sealing ring 18. The central tube 25 is hermetically connected to the upper cone 19 via a sixth sealing ring 20. The lower cone pushing cylinder 30 and the central tube 25 are sealed by a seventh sealing ring 28.

[0075] In a preferred embodiment of the described hydraulic internal cutter for cutting a single-layer solid expandable casing, the support sleeve 15 fixes the cutter body 1 by means of threads and a second internal hexagonal socket set screw 14. The lower cone pushing cylinder 30 and the lower cone 24 are connected by a second pin shaft 26 and a second internal hexagonal flat end set screw 27. The central tube 25 and the guide shoe 35 are connected and fixed by means of threads and a fourth internal hexagonal socket set screw 34.

[0076] In a preferred embodiment of the described hydraulic internal cutter for cutting a single-layer solid expandable casing, 4 slips 23 are evenly distributed on the 360-degree circumference at intervals of 90 degrees.

[0077] In a preferred embodiment of the described hydraulic internal cutter for cutting a single-layer solid expandable casing, the slip cover 21 is welded to the bottom end of the upper cone connecting sleeve 13. The lower cone 24 is limited in the downward movement direction via the slip cover 21.

[0078] In one embodiment, a hydraulic internal cutter for cutting a single-layer solid expandable casing includes, from top to bottom, a cutter body 1, a blade 4, a blade support 5, a blade return spring retaining ring 6, a blade return spring 8, a blade push cylinder 9, an upper cone connecting sleeve 13, a support sleeve 15, a steel ball 16, an upper cone 19, a slip housing 21, a leaf spring 22, slips 23, a lower cone 24, a central tube 25, a lower cone push cylinder 30, a lower cone return spring 31, a lower cone return spring retaining ring 33, and a guide shoe 35. The cutter body 1 and the blade 4 are fixedly connected by the first pin shaft 2 and the first hexagon socket head cap screw 3; the blades 4 are evenly distributed on the 360-degree circumference at intervals of 120 degrees; the blade support 5 is sleeved on the cutter body 1; the blade support 5 is threadedly connected to the blade push cylinder 9; the blade return spring 8 is sleeved between the cutter body 1 and the blade push cylinder 9; the blade push cylinder 9 and the cutter body 1 are sealed by a first sealing ring 10; the top of the blade return spring 8 is limited by the blade return spring retaining ring 6, and the blade return spring retaining ring 6 is fixed to the cutter body 1 by a thread and a first hexagon socket head cap screw 7; the upper cone connecting sleeve 13 and the upper cone 19 are threadedly connected; the upper cone connecting sleeve 13 and the cutter body 1 are sealed by a third sealing ring 12; the support sleeve 15 and the cutter body 1 are fixed by a thread and a second hexagon socket head cap screw 14; the upper cone 19 and the cutter body 1 are sealed by a sealing ring; the upper cone 19 and the upper cone connecting sleeve 13 are sealed by a sealing ring; a plurality of the steel balls 16 are arranged between the support sleeve 15 and the upper cone connecting sleeve 13; the upper cone 19 and the central tube 25 are threadedly connected; the upper cone 19 and the central tube 25 are sealed by a fourth sealing ring 17; the slips 23 are sleeved on the central tube 25 and are placed between the upper and lower cones 24; the slip housing 21 is sleeved outside the slips 23; the leaf spring 22 is arranged between the slips 23 and the slip housing 21; the 4 slips 23 are evenly distributed on the 360-degree circumference at intervals of 90 degrees; the upper cone connecting sleeve 13 and the slip housing 21 are fixedly connected by welding; the lower cone push cylinder 30 and the lower cone 24 are connected by the second pin shaft 26 and the second hexagon socket head cap screw 27; the lower cone push cylinder 30 and the central tube 25 are sealed by a seventh sealing ring 28; the lower cone push cylinder 30 and the lower cone return spring retaining ring 33 are fixedly connected by a thread and a third hexagon socket head cap screw 32; the lower cone return spring 31 is sleeved between the lower cone push cylinder 30 and the central tube 25; the central tube 25 and the guide shoe 35 are fixedly connected by a thread and a fourth hexagon socket head cap screw 34.

[0079] In one embodiment, in a hydraulic internal cutter for cutting a single-layer expandable casing, the expandable casing 38 is sleeved inside the completion casing 36. A plurality of sealing rubber cylinders 37 are provided between the expandable casing 38 and the completion casing 36. The hydraulic internal cutter is movably arranged inside the expandable casing 38. The hydraulic internal cutter includes,

[0080] A cutter body 1, which is a tubular structure with a hollow channel. The cutter body 1 is provided with grooves in the circumferential direction;

[0081] A plurality of blades 4, which are evenly distributed on the cutter body 1 in the circumferential direction. The blades 4 are rotatably arranged in the grooves via the first pin shaft 2. The first hexagon socket flat end set screw 3 is fixedly connected to the blades 4. The blades 4 are evenly distributed on the 360-degree circumference at an interval of 120 degrees;

[0082] A blade support body 5, which is movably sleeved on the cutter body 1 to abut against the blades 4 or move away from the blades 4;

[0083] A blade pushing hydraulic cylinder 9, which is movably sleeved on the cutter body 1 and is threadedly connected to the blade support body 5 to drive the blade support body 5. The blade pushing hydraulic cylinder 9 communicates with the hollow channel; the blade pushing hydraulic cylinder 9 is sealed with the cutter body 1 through the first sealing ring 10,

[0084] A blade return spring 8, which is sleeved between the cutter body 1 and the blade pushing hydraulic cylinder 9; the top end of the blade return spring 8 is limited by the blade return spring retaining ring 6. The blade return spring retaining ring 6 is fixed on the cutter body 1 through threads and the first hexagon socket cone end set screw 7,

[0085] An upper cone connection sleeve 13, which is sleeved on the cutter body 1. The top end of the upper cone connection sleeve 13 extends between the blade pushing hydraulic cylinder 9 and the cutter body 1. The upper cone connection sleeve 13 is sealingly connected to the blade pushing hydraulic cylinder 9 through the second sealing ring 11. The upper cone connection sleeve 13 is sealingly connected to the cutter body 1 through the third sealing ring 12. The upper cone connection sleeve 13 is fixed to the cutter body 1 through threads and the hexagon socket cone end set screw;

[0086] An upper cone 19, which is threadedly connected to the upper cone connection sleeve 13. The upper cone 19 is sealed with the upper cone connection sleeve 13 through the fourth sealing ring 17. The upper cone 19 is sealed with the cutter body 1 through the fifth sealing ring 18,

[0087] Support sleeve 15, which is arranged between the upper conical connecting sleeve 13 and the cutter body 1. The support sleeve 15 is fixedly connected to the cutter body 1. A number of steel balls 16 are arranged between the support sleeve 15 and the upper conical connecting sleeve 13. The support sleeve 15 fixes the cutter body 1 through a thread and a second internal hexagonal cone end set screw 14. The cutter body 1 drives the support sleeve 15 and the blade 4 to rotate and cut the expansion casing 38 layer by layer.

[0088] Central tube 25, which is threadedly connected to the inner wall of the upper cone 19. The central tube 25 communicates with the hollow channel. The central tube 25 is hermetically connected to the upper cone 19 through a sixth sealing ring 20.

[0089] Multiple slips 23, which are sleeved on the central tube 25 and are evenly distributed in the circumferential direction. The slips 23 are placed between the upper cone 19 and the lower cone 24 and can radially extend outwards. Four slips 23 are evenly distributed on the 360-degree circumference at intervals of 90 degrees.

[0090] Slip cover 21, which is sleeved outside the slips 23 and the slip cover 21 is fixedly connected to the upper conical connecting sleeve 13. Further, the slip cover 21 is welded to the bottom end of the upper conical connecting sleeve 13.

[0091] Multiple leaf springs 22, which are arranged between the slips 23 and the slip cover 21.

[0092] Lower cone 24, which is movably sleeved on the central tube 25. Further, the lower cone 24 is limited in the downward movement direction by the slip cover 21.

[0093] Lower cone pushing hydraulic cylinder 30, which is movably sleeved on the central tube 25, and the lower cone pushing hydraulic cylinder 30 is fixedly connected to the lower cone 24. The lower cone pushing hydraulic cylinder 30 communicates with the hollow tube. Further, the lower cone pushing hydraulic cylinder 30 and the lower cone 24 are connected by the second pin shaft 26 and the second internal hexagonal flat end set screw 27. The lower cone pushing hydraulic cylinder 30 and the central tube 25 are sealed by a seventh sealing ring 28.

[0094] Lower cone return spring 31, which is sleeved between the lower cone pushing hydraulic cylinder 30 and the central tube 25.

[0095] Lower cone return spring retaining ring 33, which is sleeved between the lower cone pushing hydraulic cylinder 30 and the central tube 25 and is located at the bottom end of the lower cone return spring 31. The lower cone return spring retaining ring 33 is connected and fixed to the lower cone pushing hydraulic cylinder 30 through a thread and a third internal hexagonal cone end set screw 32.

[0096] The guide shoe 35 is fixedly connected to the central pipe 25, and the central pipe 25 is communicated with the central pipe 25. Further, the central pipe 25 and the guide shoe 35 are fixedly connected by a thread and a fourth hexagon socket set screw 34 with a cone end.

[0097] In one embodiment, the lower cone pushes the hydraulic cylinder 30 to seal and cut off the lower cone return spring 31 through the eighth sealing ring 29.

[0098] The cutting method of a hydraulic internal cutter for cutting a single-layer expandable casing includes the following steps:

[0099] The expandable casing 38 is sleeved in the completion casing 36. A plurality of seal rubber cylinders 37 are arranged between the expandable casing 38 and the completion casing 36. The hydraulic internal cutter is movably arranged in the expandable casing 38.

[0100] Step 1: Pump in the workover fluid. The workover fluid enters the blade pushing hydraulic cylinder 9, the lower cone pushing hydraulic cylinder 30, and the guide shoe 35 along the hollow channel respectively.

[0101] Step 2: The throttling pressure pushes the lower cone pushing hydraulic cylinder 30 to move upward. The lower cone pushing hydraulic cylinder 30 squeezes the lower cone return spring 31 upward, and pushes the lower cone 24 to move upward. Under the action of the upward force of the lower cone 24, the slips 23 radially extend outward and are anchored on the inner wall of the expandable casing 38. The throttling pressure pushes the blade pushing hydraulic cylinder 9 to move upward. The blade pushing hydraulic cylinder 9 squeezes the blade return spring 8 upward, and pushes the blade support 5 to move upward. The blade support body 5 contacts the bottom end of the blade 4 upward, propping up the tip of the blade 4 and pressing it against the inner wall of the expandable casing 38. Press down the drill string. The cutter body 1 is connected with the support sleeve 15 and pressed down on the support ball. At this time, rotate the drill string. The cutter body 1 drives the support sleeve 15 and the blade 4 to rotate and cut the expandable casing 38 layer by layer. By controlling the throttling pressure through the displacement, the tip of the blade 4 is always in contact with the inner wall of the expandable casing 38 for cutting. The expandable pipe is cut layer by layer by the blade 4. When the expandable casing 38 is completely cut through, relieve the pressure. The lower cone pushing hydraulic cylinder 30 moves downward under the elastic force of the lower cone return spring 31, dragging the lower cone 24 to move downward. The slips 23 lose the support of the lower cone 24 and radially reset under the elastic force of the leaf spring 22, disengaging from the anchoring position of the expandable casing. The blade pushing hydraulic cylinder 9 moves downward under the elastic force of the blade return spring 8, dragging the blade support body 5 to move downward. The blade 4 loses the effective support of the blade support body 5 and resets and retracts into the cutter body 1. At this time, the entire cutter is completely out of contact with the inner wall of the expandable casing 38.

[0102] Step 3: Move the hydraulic internal cutter downward and repeat Step 2 to execute the segmented cutting procedure for each seal rubber cylinder 37 part until the whole expandable casing 38 is completely cut into several sections, and the pipe cutting is ended.

[0103] In one embodiment, asFigure 2 The completion casing 36 shown in the figure is damaged, and an expansion casing 38 is used to repair the casing, and multiple sealing rubber tubes 37 are used to seal the damaged section to ensure the integrity of the wellbore. Due to production needs, a hydraulic internal cutter is used to cut the expansion casing 38. First, use a drilling tool to lower a hydraulic inner cutter used for cutting a single-layer solid expansion casing into the expansion casing, pump in workover fluid for circulation, and the workover fluid enters the blade push cylinder 9, the lower cone push cylinder 30, and the guide shoe 35 circulation channel along the inner circulation channel respectively, and the throttling pressure pushes the lower cone push cylinder 30 upward, and the lower cone push cylinder 30 squeezes the lower cone reset spring 31 upward, pushing the lower cone 24 upward, and the slip 23 extends radially outward under the action of the upward force of the lower cone 24 and is anchored on the inner wall of the expansion casing 38; the throttling pressure pushes the blade push cylinder 9 upward, and the blade push cylinder 9 squeezes the blade reset spring 8 upward, pushing the blade support body 5 upward, and the blade support body 5 contacts the bottom end of the blade 4 upward, supporting the tip of the blade 4 The expansion casing 38 is cut layer by layer by the blade 4. The expansion casing 38 is cut layer by layer by the blade 4. The blade 4 is pushed upward by the blade support body 5 to achieve the maximum outer diameter of the completion casing 36. When the expansion sleeve 38 is completely cut through, the pressure is released, and the lower cone pushes the hydraulic cylinder 30 downward under the elastic force of the lower cone reset spring 31, dragging the lower cone 24 downward. The cava 23 loses the support of the lower cone 24, and under the elastic force of the leaf spring 22, the cava 23 is reset in the radial direction and detached from the anchoring position of the expansion sleeve 38. The blade pushes the hydraulic cylinder 9 downward under the elastic force of the blade reset spring 8, dragging the blade support body 5 downward. The blade 4 loses the effective support of the blade support body 5 and is reset and retracted into the cutter body 1. At this time, the entire cutter does not contact the inner wall of the expansion sleeve 38 at all. Move the cutting knife downward, repeat the above steps, and execute the segmented cutting procedure of each sealing rubber tube 37 until the entire expansion casing 38 is completely cut into several sections. The pipe cutting procedure is completed, the drill is pulled out, and the spear is lowered to salvage each section of the expansion casing one by one. After the expansion casing is caught, the drill bit is lifted to break the friction resistance of the rubber tube, and this section of the expansion casing is salvaged. Repeat several times to complete the salvage of all the expansion casings.

[0104] Finally, it should be noted that the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0105] Only some exemplary embodiments of the present invention have been described above by way of illustration. Undoubtedly, for those of ordinary skill in the art, the described embodiments can be modified in various different ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A hydraulic internal cutter for cutting a single-layer solid expandable casing, characterized in that, It includes a cutter body, which is a tubular structure with a hollow channel, and the cutter body is provided with grooves in the circumferential direction; a plurality of blades, which are evenly distributed on the cutter body in the circumferential direction, and the blades are rotatably arranged in the grooves; a blade support body, which is movably sleeved on the cutter body to abut against the blade or away from the blade; a blade pushing hydraulic cylinder, which is movably sleeved on the cutter body and threadedly connected to the blade support body to drive the blade support body, and the blade pushing hydraulic cylinder communicates with the hollow channel; a blade return spring, which is sleeved between the cutter body and the blade pushing hydraulic cylinder; an upper cone connecting sleeve, which is sleeved on the cutter body, and the top end of the upper cone connecting sleeve extends between the blade pushing hydraulic cylinder and the cutter body; an upper cone, which is threadedly connected to the upper cone connecting sleeve; a support sleeve, which is arranged between the upper cone connecting sleeve and the cutter body, the support sleeve is fixedly connected to the cutter body, and a number of steel balls are arranged between the support sleeve and the upper cone connecting sleeve; a central tube, which is threadedly connected to the inner wall of the upper cone, and the central tube communicates with the hollow channel; a lower cone, which is movably sleeved on the central tube; a plurality of slips, which are sleeved on the central tube and evenly distributed in the circumferential direction, and the slips are placed between the upper cone and the lower cone and can radially extend outwards; a slip cover, which is sleeved outside the slips and the slip cover is fixedly connected to the upper cone connecting sleeve; a plurality of leaf springs, which are arranged between the slips and the slip cover; a lower cone pushing hydraulic cylinder, which is movably sleeved on the central tube, and the lower cone pushing hydraulic cylinder is fixedly connected to the lower cone, and the lower cone pushing hydraulic cylinder communicates with the hollow tube; a lower cone return spring, which is sleeved between the lower cone pushing hydraulic cylinder and the central tube; a guide shoe, which is fixedly connected to the central tube, and the central tube communicates with the central tube.

2. The hydraulic internal cutter for cutting a single-layer solid expandable casing according to claim 1, characterized in that, Liquid enters the blade pushing hydraulic cylinder, the lower cone pushing hydraulic cylinder and the guide shoe respectively along the hollow channel, and the throttling pressure pushes the lower cone pushing hydraulic cylinder to move upwards. The lower cone pushing hydraulic cylinder upwards squeezes the lower cone return spring and pushes the lower cone to move upwards. Under the action of the upward force of the lower cone, the slips radially extend outwards.

3. The hydraulic internal cutter for cutting a single-layer solid expandable casing according to claim 2, characterized in that, The throttling pressure pushes the blade pushing hydraulic cylinder to move upwards. The blade pushing hydraulic cylinder upwards squeezes the blade return spring and pushes the blade support body to move upwards. The blade support body upwards contacts the bottom end of the blade and props up the tip of the blade. The cutter body is connected to the support sleeve and presses down on the support ball, and the cutter body drives the support sleeve and the blade to rotate to cut layer by layer.

4. The hydraulic internal cutter for cutting a single-layer solid expandable casing according to claim 1, characterized in that, The blade is rotatably arranged in the groove via a first pin shaft, and a first internal hexagonal flat end set screw is fixedly connected to the blade. The blades are evenly distributed on the 360-degree circumference at intervals of 120 degrees.

5. The hydraulic internal cutter for cutting a single-layer solid expandable casing according to claim 1, characterized in that, The top end of the blade return spring is limited by a blade return spring retaining ring, and the blade return spring retaining ring is fixed on the cutter body by thread and an internal hexagonal cone end set screw. The lower cone return spring retaining ring is sleeved between the lower cone pushing hydraulic cylinder and the central tube and is located at the bottom end of the lower cone return spring. The lower cone return spring retaining ring is connected and fixed to the lower cone pushing hydraulic cylinder by thread and an internal hexagonal cone end set screw.

6. The hydraulic internal cutter for cutting a single-layer solid expandable casing according to claim 1, characterized in that, The blade pushing cylinder and the cutter body are sealed by the first sealing ring, the upper cone connecting sleeve is sealed and connected to the blade pushing cylinder via the second sealing ring, the upper cone connecting sleeve is sealed and connected to the cutter body via the third sealing ring, the upper cone and the upper cone connecting sleeve are sealed by the fourth sealing ring, the upper cone and the cutter body are sealed by the fifth sealing ring, the center tube is sealed and connected to the upper cone by the sixth sealing ring, and the lower cone pushing cylinder and the center tube are sealed by the seventh sealing ring.

7. The hydraulic internal cutter for cutting a single-layer solid expandable casing according to claim 1, characterized in that, The support sleeve fixes the cutter body through threads and a second hexagonal cone-end set screw, the lower cone push cylinder is connected to the lower cone through a second pin shaft and a second hexagonal flat-end set screw, and the center tube is connected and fixed to the guide shoe through threads and a fourth hexagonal cone-end set screw.

8. The hydraulic internal cutter for cutting a single-layer solid expandable casing according to claim 1, characterized in that, The four slips are evenly distributed on a 360-degree circumference at 90-degree intervals.

9. The hydraulic internal cutter for cutting a single-layer solid expandable casing according to claim 1, characterized in that, The slip cover is welded to the bottom end of the upper cone connecting sleeve, and the lower cone is limited by the slip cover in the downward moving direction.

10. A cutting method of a hydraulic internal cutter for cutting a single-layer solid expandable casing according to any one of claims 1-9, characterized in that, It includes the following steps, The expansion casing is sleeved in the completion casing, a plurality of sealing rubber tubes are arranged between the expansion casing and the completion casing, and a hydraulic internal cutter is movably arranged in the expansion casing. Step 1: Pump in the workover fluid, which enters the blade push cylinder, the lower cone push cylinder and the guide shoe along the hollow channel. Step 2: The throttling pressure pushes the lower cone to push the hydraulic cylinder upward, and the lower cone pushes the hydraulic cylinder upward to squeeze the lower cone return spring, pushing the lower cone upward. Under the action of the upward force of the lower cone, the slips extend radially outward and are anchored on the inner wall of the expansion casing; The throttling pressure pushes the blade push cylinder upward, and the blade push cylinder squeezes the blade reset spring upward, pushing the blade support upward, and the blade support body contacts the bottom end of the blade upward, propping up the tip of the blade and pressing it against the inner wall of the expansion casing, pressing the drill bit downward, and the cutter body connected to the support sleeve is pressed down on the support ball. At this time, the drill bit is rotated, and the cutter body rotates with the support sleeve and the blade to cut the expansion casing layer by layer. The throttling pressure is controlled by the displacement, so that the tip of the blade is always in contact with the inner wall of the expansion casing, and the expansion tube is cut by the blade layer by layer. Layer cutting, when the expansion casing is completely cut through, the pressure is released, the lower cone pushes the hydraulic cylinder downward under the elastic force of the lower cone reset spring, drags the lower cone downward, the slips lose the support of the lower cone, under the elastic force of the leaf spring, the slips reset along the radial direction and detach from the anchoring position of the expansion casing, the blade pushes the hydraulic cylinder downward under the elastic force of the blade reset spring, drags the blade support body downward, the blade loses the effective support of the blade support body, resets and retracts into the cutter body, at this time the entire cutter does not contact the inner wall of the expansion casing at all; Step 3, move the hydraulic inner cutter downward, repeat step 2, and execute the segmented cutting procedure of each sealant tube part until the entire expansion casing is completely cut into several sections, and the pipe cutting is completed.

Images