Split type hydraulic full-hole centralizer, method thereof and casing curved well shaping pipe column

Abstract

The invention discloses a split type hydraulic full-hole centralizer, a method thereof and a casing curved well shaping pipe column, the split type hydraulic full-hole centralizer comprises a hydraulic mechanism and further comprises a split type centralizing mechanism, and the split type centralizing mechanism is arranged at the lower end of the hydraulic mechanism; a lower jacking cylinder, a sliding valve and a connecting cylinder are arranged in the split type righting mechanism; the lower ends of the sliding petals are rotationally connected with the connecting cylinder, the upper end of the lower jacking cylinder is connected with the hydraulic mechanism, the upper ends of the sliding petals are provided with transmission grooves inclining inwards with the rotary connecting shaft as the center, and the lower end of the lower jacking cylinder makes contact with the upper ends of the transmission grooves; when the lower ejection cylinder is inserted into the transmission groove, the transmission groove is straightened, and the sliding valve is ejected outwards around the rotating connecting shaft. According to the invention, high centralizing force and seamless centralizing can be realized, and full-hole centralizing in a slotted casing can be realized; and the centralizing mechanism uses few mechanical parts, is high in reliability and can stably work in an underground environment.

Description

Technical Field

[0001] The present invention relates to the technical field of oilfield development, and more particularly to a split-type hydraulic full-hole centralizer and its method and a casing bending well shaping string. Background Art

[0002] As major domestic oilfields enter the middle and late stages of development, with the large-scale use of various oil production and oil increment technologies, such as heavy oil thermal recovery, water injection for energy supplementation, etc., the downhole casing conditions have become increasingly harsh, and the downhole situations of casing bending have gradually increased. However, the current effective technologies for treating casing bending wells are relatively scarce. For such situations, major oilfields mostly operate with problems. If it is really difficult to maintain, sidetracking wells are used to replace the bent well section. However, recently, due to the low international oil price, major oilfields have all compressed costs and reduced investments. Even though the cost of sidetracking wells is much lower than that of drilling new wells, it cannot be implemented on a large scale to meet the huge demand for casing bending wells. Many casing bending wells are directly scrapped because they cannot be economically and effectively treated. Therefore, once the casing bending problem occurs, no matter how it is handled, it will cause great economic losses to the oilfield.

[0003] The difficulty in treating casing bending wells lies in that if the bent casing is to be straightened after bending, the shaping string must overcome the stress of the bent casing itself, and at the same time, there must be a deformation space outside the casing for casing straightening. Currently, the stress of the bent casing itself can be overcome by stress release through punching or slitting. However, compared with the two, casing slitting is superior to casing punching both in terms of stress release of the casing itself and preparation of the deformation space outside the casing. In the future series of technologies for treating casing bending wells, the stress release technology will surely adopt the casing slitting method. However, in the current treatment process, due to the lack of near-point support and centralization, according to the lever principle, although this scheme can achieve a certain treatment effect, it causes greater damage to the hydraulic boosting mechanism. There is a risk of bending or even breaking of the hydraulic cylinder mandrel theoretically. If near-point support and centralization are added, the centralizing force of the existing elastic centralizer is very small, and the outer diameter of the rigid centralizer needs to leave a certain gap with the inner wall of the casing due to the need for string lowering, resulting in poor centralizing effect, and neither can meet the full-hole centralizing requirements in the casing after slitting. Therefore, there is an urgent need for a safer casing bending well shaping string and a supporting centralizer to solve the above problems.

[0004] Publication (Announcement) Number: CN116066000A discloses a casing sandblasting and slotting cavity-forming string and its shaping operation method. The string includes a hydraulic variable-diameter ball centralizer, a reverse circulation wash well valve, and a hydraulic sandblasting and slotting tool arranged from top to bottom in sequence; its casing deformation and shaping operation method is completed through eight steps: string assembly and lowering, wellhead device assembly and connection of the surface pumping system, casing sandblasting and slotting and cavity-forming operation outside the casing, lifting the string, casing shaping, well flushing verification, casing reinforcement and plug drilling, and well completion; when the string is used for casing reduction and shaping operation in oilfield workover, it can not only longitudinally cut slots in the deformed section of the casing, but also effectively clean the formation cuttings outside the casing, remove the external stress on the casing, provide a prerequisite for casing shaping, and effectively improve the shaping success rate; in addition, in terms of structural design, it is not only applicable to the operation requirements of casing sections with different inner diameters, but also can solve the possible problem of string blockage.

[0005] When the existing technology is used, there is a lack of near-point support and centralization, which causes greater damage to the hydraulic force-increasing mechanism, and there is a risk of bending or even breaking of the hydraulic cylinder core shaft.

[0006] Publication (Announcement) Number: CN108561081B discloses a turbine cam type downhole centralizer, which consists of a power assembly, a deviation rectification assembly, and a lower sub. The front end of the power assembly is connected to the deviation rectification assembly, and the front end of the deviation rectification assembly is connected to the lower sub. During drilling, when the well deviation occurs, the heavier side of the weighted casing automatically rotates to the low side of the wellbore under the action of gravity through bearing a and bearing c, driving the connecting rod seat to rotate, so that connecting rod a and connecting rod b are always located on the high side of the wellbore. The turbine rotor of the power assembly converts the liquid energy into rotational mechanical energy, driving the central tube to rotate. The roller seat rotates synchronously with the central tube, causing the cam to reciprocate up and down, thereby driving connecting rod a and connecting rod b to continuously push against the well wall, generating a periodic reaction force to correct the well deviation and realizing normal drilling.

[0007] Multiple pin connections are used in the pop-up centralization part of the existing technology, significantly increasing the probability of failures underground.

[0008] Publication (Announcement) Number: CN214787235U, which discloses a centralizer for oil exploitation, including a fastening device and a supporting device. The fastening device includes an upper threaded pipe, a lower threaded pipe and a connecting sleeve. The upper threaded pipe and the lower threaded pipe are respectively connected with an upper sucker rod and a lower sucker rod. A first annular convex ring is provided at the lower end of the upper threaded pipe, and a second annular convex ring is provided at the upper end of the lower threaded pipe. The connecting sleeve is formed by enclosing at least two arc-shaped plates. The inner wall of the upper part of the arc-shaped plate is provided with a first groove, and the inner wall of the lower part of the arc-shaped plate is provided with a second groove. The first annular convex ring and the second annular convex ring are respectively clamped in the first groove and the second groove. The supporting device includes a guide rail and a slide bar. Two first telescopic rods are fixedly arranged on the slide bar. A scraping plate is fixedly arranged at the telescopic end of the first telescopic rod. At least one second telescopic rod is also fixedly arranged on the slide bar. A roller is rotatably connected to the telescopic end of the second telescopic rod.

[0009] This prior art cannot actively control centralization and uses many mechanical sliding structures, significantly increasing the probability of failures underground.

[0010] In summary, the technical solutions, the technical problems to be solved and the beneficial effects of the above-disclosed technologies are all different from those of the present invention. For more technical features, technical problems to be solved and beneficial effects of the present invention, there is no technical inspiration in the above-disclosed technical documents. Summary of the Invention

[0011] In view of the above-mentioned defects existing in the prior art, the object of the present invention is to provide a split-type hydraulic full-bore centralizer and its method and a casing straightening string for casing with slots, realizing high centralizing force, seamless centralization, and full-bore centralization in the slotted casing.

[0012] To achieve the above object, the present invention adopts the following technical solutions:

[0013] A split-type hydraulic full-bore centralizer includes a hydraulic mechanism and also includes a split-type centralizing mechanism. The split-type centralizing mechanism is arranged at the lower end of the hydraulic mechanism. In the split-type centralizing mechanism, there are a lower top cylinder, sliding petals and a connecting cylinder. The lower end of the sliding petals is rotatably connected to the connecting cylinder. The upper end of the lower top cylinder is connected to the hydraulic mechanism. The upper end of the sliding petals is provided with a transmission groove that inclines inward with the rotation connection shaft as the center. The lower end of the lower top cylinder contacts the upper end of the transmission groove. When the lower top cylinder is inserted into the transmission groove, the transmission groove is straightened, and the sliding petals are pushed outwards around the rotation connection shaft.

[0014] Further, both the hydraulic mechanism and the split-type centralizing mechanism are sleeved on the central pipe.

[0015] Further, the hydraulic mechanism includes a cylinder seat, a hydraulic cylinder, an upper top cylinder, a return spring and a limiting cylinder.

[0016] Specifically, the center of the cylinder base is through, the lower end of the inner wall of the cylinder base is connected to the upper end of the outer wall of the central pipe, and the hydraulic cylinder is sleeved with the cylinder base from below the cylinder base;

[0017] Specifically, a first sealing ring is arranged on the outer wall of the cylinder base for sealing with the inner wall of the upper end of the hydraulic cylinder; a second sealing ring is arranged on the inner wall of the lower end of the hydraulic cylinder for sealing with the outer wall of the central pipe;

[0018] Specifically, the upper end of the upper top cylinder is connected to the lower end of the hydraulic cylinder, the limiting cylinder is arranged on the outer wall of the upper top cylinder, the return spring is sleeved outside the upper top cylinder, and the return spring presses the hydraulic cylinder upward and presses the limiting cylinder downward;

[0019] Specifically, a pressure transmission hole is arranged between the central pipe below the cylinder base and the second sealing ring.

[0020] Further, the split type centering mechanism includes an outer cylinder, a lower top cylinder, a sliding flap, and a connecting cylinder;

[0021] Specifically, the inner wall of the upper end of the outer cylinder is connected to the outer wall of the limiting cylinder, the inner wall of the connecting cylinder is fixedly connected to the outer wall of the central pipe, and the outer wall of the connecting cylinder is connected to the lower end of the outer cylinder;

[0022] Specifically, the outer cylinder is provided with at least two uniformly distributed sliding flap through grooves, and each sliding flap through groove is provided with a sliding flap;

[0023] Specifically, the lower end of the sliding flap is rotationally connected to the upper end of the connecting cylinder through a rotating pin, the lower top cylinder is below the limiting cylinder, and the upper end of the lower top cylinder is connected to the outer wall of the upper top cylinder;

[0024] Specifically, a transmission groove is arranged at the upper end of the sliding flap, the shape of the transmission groove is the same as the outer shape of the lower end of the lower top cylinder, the transmission groove is inclined towards the central pipe with the rotating pin as the fulcrum, and the lower end of the lower top cylinder contacts the upper end of the transmission groove.

[0025] Further, a joint thread is arranged at the upper end of the inner wall of the cylinder base, and a lower joint is arranged at the lower end of the inner wall of the central pipe.

[0026] Further, the outer wall of the cylinder base is a precision machined sealing surface, the outer wall of the cylinder base is provided with at least one first sealing ring groove for placing the first sealing ring, the upper end of the inner wall of the cylinder base is provided with a first joint thread, the lower end is provided with a first internal thread, and a tapered surface is used for transition between the first joint thread and the first internal thread;

[0027] Specifically, the hydraulic cylinder is of a cylindrical structure, and three diameter surfaces of large, small, and medium are successively machined inside the hydraulic cylinder from top to bottom. Among them, the small diameter surface and the large diameter surface are precision machined sealing surfaces, at least one second sealing ring groove is machined on the small diameter surface for placing the second sealing ring, a second internal thread is machined on the medium diameter surface for connecting with the upper top cylinder, and a nail groove is machined on the outer wall corresponding to the medium diameter surface;

[0028] Specifically, the central tube is of a stepped tube structure. The upper end of the central tube is provided with a first external thread, and the lower end is provided with a fifth external thread. Above the fifth external thread, a large-diameter external thread is machined for connecting the connecting cylinder.

[0029] Specifically, the upper end inner wall of the lower joint is provided with a fifth internal thread, and the lower end is provided with a second joint thread. The fifth internal thread and the second joint thread are transitioned through a tapered surface.

[0030] Further, the upper top cylinder is of a special-shaped cylinder structure. The upper end of its outer wall is machined with a second external thread. The outer wall of the upper top cylinder is successively a flat surface, a convex ring, and a tapered support surface from top to bottom. The convex ring is machined with a third external thread for connecting with the lower top cylinder. The limiting cylinder is arranged above the convex ring.

[0031] Specifically, the upper end inner wall of the lower top cylinder is provided with a third internal thread, and the lower end is machined with an inner tapered surface. The lower end of its outer wall is machined with an outer tapered surface. The tapered surface thickness of the lower top cylinder gradually decreases from top to bottom.

[0032] Specifically, the upper end of the limiting cylinder is provided with a limiting step. The lower end outer wall of the limiting cylinder is provided with a fourth external thread for connecting with the outer cylinder. The upper end inner wall of the outer cylinder is machined with a fourth internal thread.

[0033] Further, the lower end of the sliding flap is provided with a first hinge support. A first rotation pin hole is machined in the first hinge support for connecting with the connecting cylinder. The outer wall of the sliding flap is an arc surface.

[0034] Specifically, the inner wall of the connecting cylinder is machined with a large-diameter internal thread. The outer wall is provided with a pin socket for pin connection with the lower end of the outer cylinder. The lower end outer wall of the connecting cylinder is provided with an outer cylinder limiting seat. The upper end of the connecting cylinder is provided with a second hinge support. A second rotation pin hole is arranged in the second hinge support.

[0035] Specifically, the rotation pin passes through the first rotation pin hole and the second rotation pin hole to complete the rotational connection between the sliding flap and the connecting cylinder.

[0036] To achieve the above object, the present invention adopts the following technical solutions:

[0037] A method for using a split-type hydraulic full-bore centralizer, comprising the following steps:

[0038] S1. Pressurize from the wellhead. The pressure passes through the pressure transmission hole to push the hydraulic cylinder downward to store energy for the return spring. The lower end outer tapered surface of the lower top cylinder enters the transmission groove in the sliding flap. The transmission groove is aligned by the lower top cylinder, and the sliding flap moves outward around the rotation pin, thereby expanding the sliding flap through groove. The arc surface of the outer wall of the sliding flap contacts the inner wall of the casing to achieve centralizing and straightening.

[0039] S2. After the hydraulic pressure disappears, the return spring pushes the hydraulic cylinder upward, and the inner conical surface at the lower end of the lower ejector barrel presses against the upper end of the rotating groove inside the sliding valve, causing the sliding valve to contract back into the outer cylinder and return to its original state.

[0040] To achieve the above object, the present invention adopts the following technical solutions:

[0041] A casing bending well shaping string of a split type hydraulic full hole centralizer includes a tubing string, and further includes a hydraulic anchor, a hydraulic force increasing tool, a split type hydraulic full hole centralizer, and a variable stiffness shaper connected in sequence from top to bottom. The upper end of the hydraulic anchor is connected to the tubing string; a hydraulic mechanism, a lower ejector barrel, a sliding valve, and a connecting cylinder are arranged in the split type hydraulic full hole centralizer; the lower end of the sliding valve is rotatably connected to the connecting cylinder, the upper end of the lower ejector barrel is connected to the hydraulic mechanism, a transmission groove inclined inward with the rotation connecting shaft as the center is arranged at the upper end of the sliding valve, and the lower end of the lower ejector barrel contacts the upper end of the transmission groove.

[0042] The present invention has the following beneficial effects compared with the prior art:

[0043] 1. It can achieve high centralizing force, with no gap in centralizing, and can perform full hole centralizing in the slotted casing.

[0044] 2. The centralizing mechanism uses fewer mechanical parts and has high reliability, and can work stably in the downhole environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is a schematic structural diagram of a casing bending well shaping string of a split type hydraulic full hole centralizer of the present invention;

[0046] Figure 2 is a schematic structural diagram of a split type hydraulic full hole centralizer of the present invention;

[0047] Figure 3 is a schematic structural diagram of a cylinder seat of a split type hydraulic full hole centralizer of the present invention;

[0048] Figure 4 is a schematic structural diagram of a hydraulic cylinder of a split type hydraulic full hole centralizer of the present invention;

[0049] Figure 5 is a schematic structural diagram of a central tube of a split type hydraulic full hole centralizer of the present invention;

[0050] Figure 6 is a schematic structural diagram of an upper ejector barrel of a split type hydraulic full hole centralizer of the present invention;

[0051] Figure 7 is a schematic structural diagram of a limit cylinder of a split type hydraulic full hole centralizer of the present invention;

[0052] Figure 8It is a schematic structural diagram of the outer cylinder of a split-type hydraulic full-bore centralizer according to the present invention;

[0053] Figure 9 It is a schematic structural diagram of the lower top cylinder of a split-type hydraulic full-bore centralizer according to the present invention;

[0054] Figure 10 It is a schematic structural diagram of the sliding flap of a split-type hydraulic full-bore centralizer according to the present invention;

[0055] Figure 11 It is a schematic structural diagram of the connecting cylinder of a split-type hydraulic full-bore centralizer according to the present invention;

[0056] Figure 12 It is a schematic structural diagram of the lower sub of a split-type hydraulic full-bore centralizer according to the present invention;

[0057] In the figure: 1, tubing; 2, hydraulic anchor; 3, hydraulic force increasing tool; 4, split-type hydraulic full-bore centralizer; 5, variable stiffness shaper; 4-1, cylinder seat; 4-2, hydraulic cylinder; 4-21, small diameter surface; 4-22, large diameter surface; 4-23, middle diameter surface; 4-24, nail groove; 4-3, central tube; 4-31, pressure transmission hole; 4-32, large diameter external thread; 4-4, upper top cylinder; 4-41, convex ring; 4-42, conical support surface; 4-5, return spring; 4-6, limit cylinder; 4-61, limit step; 4-7, outer cylinder; 4-71, sliding flap through groove; 4-8, lower top cylinder; 4-81, outer conical surface; 4-82, inner conical surface; 4-9, sliding flap; 4-91, transmission groove; 4-92, arc surface; 4-93, first pin hole; 4-94, first hinge support; 4-10, pin; 4-11, connecting cylinder; 4-110, second hinge support; 4-111, second pin hole; 4-1112, pin socket; 4-1113, outer cylinder limit seat; 4-12, lower sub. Specific embodiments

[0058] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. 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.

[0059] Embodiment 1:

[0060] Please refer to Figure 1 , Figure 2 , Figure 5 , Figure 8 , Figure 10 , a split-type hydraulic full-bore centralizer provided by the present invention includes a hydraulic mechanism and a split-type centralizing mechanism connected in sequence;

[0061] The hydraulic mechanism and the split-type centralizing mechanism are both sleeved on the central pipe 4-3. The hydraulic mechanism includes a cylinder base 4-1, a hydraulic cylinder 4-2, an upper top cylinder 4-4, a return spring 4-5, and a limit cylinder 4-6;

[0062] The center of the cylinder base 4-1 is penetrated. The lower end of the inner wall of the cylinder base 4-1 is connected to the upper end of the outer wall of the central pipe 4-3. The hydraulic cylinder 4-2 is sleeved on the cylinder base 4-1 from below the cylinder base 4-1. A first sealing ring is arranged on the outer wall of the cylinder base 4-1 for sealing with the inner wall of the upper end of the hydraulic cylinder 4-2. A second sealing ring is arranged on the inner wall of the lower end of the hydraulic cylinder 4-2 for sealing with the outer wall of the central pipe 4-3. The upper end of the upper top cylinder 4-4 is connected to the lower end of the hydraulic cylinder 4-2. The limit cylinder 4-6 is arranged on the outer wall of the upper top cylinder 4-4. The return spring 4-5 is sleeved outside the upper top cylinder 4-4. The return spring 4-5 pushes the hydraulic cylinder 4-2 upward and the limit cylinder 4-6 downward;

[0063] A pressure transmission hole 4-31 is arranged between the central pipe 4-3 and the second sealing ring below the cylinder base 4-1.

[0064] The split-type centralizing mechanism includes an outer cylinder 4-7, a lower top cylinder 4-8, a sliding flap 4-9, and a connecting cylinder 4-11. The inner wall of the upper end of the outer cylinder 4-7 is connected to the outer wall of the limit cylinder 4-6. The inner wall of the connecting cylinder 4-11 is fixedly connected to the outer wall of the central pipe 4-3. The outer wall of the connecting cylinder 4-11 is connected to the lower end of the outer cylinder 4-7. The outer cylinder 4-7 is provided with at least two uniformly distributed sliding flap through grooves 4-71. Each sliding flap through groove 4-71 is provided with a sliding flap 4-9. The lower end of the sliding flap 4-9 is rotationally connected to the upper end of the connecting cylinder 4-11 through a rotating pin 4-10. The lower top cylinder 4-8 is a conical cylinder. The lower top cylinder 4-8 is below the limit cylinder 4-6. The upper end of the lower top cylinder 4-8 is connected to the outer wall of the upper top cylinder 4-4. A transmission groove 4-91 is arranged at the upper end of the sliding flap 4-9. The shape of the transmission groove 4-91 is the same as the outer shape of the lower top cylinder 4-8. The transmission groove 4-91 is inclined towards the central pipe 4-3 with the rotating pin 4-10 as the fulcrum. The lower end of the lower top cylinder 4-8 contacts the upper end of the transmission groove 4-91. When the lower end of the lower top cylinder 4-8 is completely inserted into the transmission groove 4-91, the lower top cylinder 4-8 and the transmission groove 4-91 are completely matched, and the moving groove 4-91 is straightened, so that the sliding flap 4-9 moves outward around the rotating pin 4-10.

[0065] The upper end of the inner wall of the cylinder base 4-1 is provided with a joint thread, and the lower end of the inner wall of the central pipe is provided with a lower joint 4-12.

[0066] Embodiment 2:

[0067] Based on Embodiment 1, this embodiment provides a preferred structure of the device. Please refer to Figures 1 to 12 .

[0068] As shown Figure 3 in the figure, the outer wall of the cylinder base 4-1 is a precision-machined sealing surface. At least one first sealing ring groove is provided on the outer wall of the cylinder base 4-1 for placing a first sealing ring. At the upper end of the inner wall of the cylinder base 4-1, a first joint thread is provided, and at the lower end, a first internal thread is provided. A tapered surface is used for transition between the first joint thread and the first internal thread.

[0069] As shown Figure 4 in the figure, the hydraulic cylinder 4-2 is of a cylindrical structure. Inside the hydraulic cylinder 4-2, three diameter surfaces 4-22, 4-21, and 4-23 with large, small, and medium diameters are machined in sequence from top to bottom. Among them, the small-diameter surface 4-21 and the large-diameter surface 4-22 are precision-machined sealing surfaces. At least one second sealing ring groove is machined on the small-diameter surface 4-21 for placing a second sealing ring. A second internal thread is machined on the medium-diameter surface 4-23, and a nail groove 4-24 is machined on the corresponding outer wall of the medium-diameter surface 4-23.

[0070] As shown Figure 5 in the figure, the central tube 4-3 is of a stepped tube structure. A first external thread is provided at the upper end of the central tube 4-3, and a fifth external thread is provided at the lower end. A large-diameter external thread 4-32 is machined above the fifth external thread for connecting the connecting tube 4-11.

[0071] As shown Figure 6 in the figure, the upper top cylinder 4-4 is of a special-shaped cylindrical structure. A second external thread is machined at the upper end of its outer wall. The outer wall of the upper top cylinder 4-4 is a flat surface, a convex ring 4-41, and a tapered support surface 4-42 in sequence from top to bottom. A third external thread is machined on the convex ring 4-41 for connecting with the lower top cylinder 4-8. The limiting cylinder 4-6 is arranged above the convex ring 4-41.

[0072] As shown Figure 7 in the figure, a limiting step 4-61 is provided at the upper end of the limiting cylinder 4-6. A fourth external thread is provided on the outer wall at the lower end of the limiting cylinder 4-6 for connecting with the outer cylinder 4-7.

[0073] As shown Figure 8 in the figure, a fourth internal thread is machined at the upper end of the inner wall of the outer cylinder 4-7, and three sliding flap through grooves 4-71 are machined on the wall.

[0074] As shown Figure 9 in the figure, a third internal thread is provided on the inner wall at the upper end of the lower top cylinder 4-8, and an inner tapered surface 4-82 is machined at the lower end. An outer tapered surface 4-81 is machined on the outer wall at the lower end of the lower top cylinder 4-8, and the tapered surface thickness of the lower top cylinder 4-8 gradually decreases from top to bottom.

[0075] As shown Figure 10As shown, a first hinge support 4-94 is provided at the lower end of the sliding valve 4-9. A first pin hole 4-93 is machined in the first hinge support 4-94 for connecting with the connecting cylinder 4-11. The outer wall of the sliding valve 4-9 is an arc surface 4-92.

[0076] As Figure 11 shown, large-diameter internal threads are machined on the inner wall of the connecting cylinder 4-11, and a pin socket 4-1112 is provided on the outer wall for pin connection with the lower end of the outer cylinder 4-7. An outer cylinder limit seat 4-1113 is provided at the lower end of the outer wall of the connecting cylinder 4-11. A second hinge support 4-110 is provided at the upper end of the connecting cylinder 4-11, and a second pin hole 4-111 is provided in the second hinge support 4-110.

[0077] As Figure 12 shown, a fifth internal thread is provided at the upper end of the inner wall of the lower joint 4-1, and a second joint thread is provided at the lower end. The fifth internal thread and the second joint thread are transitioned through a conical surface.

[0078] Specifically, the internal thread and the external thread with the same prefix name are connected together.

[0079] Specifically, the pin 4-10 passes through the first pin hole 4-93 and the second pin hole 4-111 to complete the rotational connection between the sliding valve 4-9 and the connecting cylinder 4-11.

[0080] Embodiment 3:

[0081] Based on Embodiment 1 or 2, a method for using a split-type hydraulic full-bore centralizer is provided:

[0082] S1. Pressurize from the wellhead. The pressure passes through the pressure transmission hole 4-31, pushes the hydraulic cylinder 4-2 downward to store energy for the return spring 4-5. The outer conical surface 4-81 at the lower end of the lower top cylinder 4-8 enters the transmission groove 4-91 in the sliding valve 4-9. The transmission groove 4-91 is aligned by the lower top cylinder 4-8, and the sliding valve 4-9 moves outward around the pin 4-10, so that the sliding valve 4-9 expands out the sliding valve through groove 4-71. The arc surface 4-92 on the outer wall of the sliding valve 4-9 contacts the inner wall of the casing to achieve centralizing and straightening.

[0083] S2. When the hydraulic pressure disappears, the return spring 4-5 pushes the hydraulic cylinder 4-2 upward. The inner conical surface 4-82 at the lower end of the lower top cylinder 4-8 presses on the upper end of the inner rotating groove 4-91 in the sliding valve 4-9, so that the sliding valve 4-9 contracts back into the outer cylinder 4-7 and returns to its original state.

[0084] Embodiment 4:

[0085] On the basis of the above embodiments, the present embodiment provides a casing bending well shaping string for a split type hydraulic full gauge centralizer, which includes a hydraulic anchor 2, a hydraulic force increasing tool 3, a split type hydraulic full gauge centralizer 4, and a variable stiffness shaper 5 connected in sequence from top to bottom; the upper end of the hydraulic anchor 2 is connected to a tubing 1.

[0086] In this application, any component itself that is not elaborated and the connection methods of various components in this application belong to the well-known technologies in the technical field. They can be directly applied and will not be elaborated further.

[0087] In the present invention, the term "a plurality of" refers to two or more, unless otherwise clearly defined. Terms such as "installation", "connection", "connection", "fixation" and other terms should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "connection" can be a direct connection or an indirect connection through an intermediate medium. 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.

[0088] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "front", "rear", 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 unit referred to must have a specific direction, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0089] In the description of this specification, the description of terms such as "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0090] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims

1. A split-type hydraulic full-bore centralizer, comprising a hydraulic mechanism, characterized in that, It further includes a split-type centering mechanism, and the split-type centering mechanism is arranged at the lower end of the hydraulic mechanism; A lower top cylinder, a sliding flap, and a connecting cylinder are arranged in the split-type centering mechanism; The lower end of the sliding flap is rotatably connected to the connecting cylinder, the upper end of the lower top cylinder is connected to the hydraulic mechanism, a transmission groove that inclines inwards with the rotation connecting shaft as the center is arranged at the upper end of the sliding flap, and the lower end of the lower top cylinder contacts the upper end of the transmission groove; When the lower top cylinder is inserted into the transmission groove, the transmission groove is straightened, and the sliding flap is pushed outwards around the rotation connecting shaft.

2. The split-type hydraulic full-bore centralizer according to claim 1, wherein Both the hydraulic mechanism and the split-type centering mechanism are sleeved on the central pipe.

3. The split hydraulic full-bore centralizer according to claim 2, wherein, The hydraulic mechanism includes a cylinder base, a hydraulic cylinder, an upper top cylinder, a return spring, and a limiting cylinder; The center of the cylinder base is penetrated, the lower end inner wall of the cylinder base is connected to the outer wall upper end of the central pipe, and the hydraulic cylinder is sleeved with the cylinder base from below the cylinder base; A first sealing ring is arranged on the outer wall of the cylinder base for sealing with the inner wall upper end of the hydraulic cylinder; a second sealing ring is arranged on the inner wall lower end of the hydraulic cylinder for sealing with the outer wall of the central pipe; The upper end of the upper top cylinder is connected to the lower end of the hydraulic cylinder, the limiting cylinder is arranged on the outer wall of the upper top cylinder, the return spring is sleeved outside the upper top cylinder, and the return spring pushes up the hydraulic cylinder to push down the limiting cylinder; A pressure transmission hole is arranged between the central pipe below the cylinder base and the second sealing ring.

4. The split-type hydraulic full-bore centralizer according to claim 3, characterized in that, The split-type centering mechanism includes an outer cylinder, a lower top cylinder, a sliding flap, and a connecting cylinder; The upper end inner wall of the outer cylinder is connected to the outer wall of the limiting cylinder, the inner wall of the connecting cylinder is fixedly connected to the outer wall of the central pipe, and the outer wall of the connecting cylinder is connected to the lower end of the outer cylinder; At least two uniformly distributed sliding flap through grooves are arranged on the outer cylinder, and a sliding flap is arranged in each sliding flap through groove; The lower end of the sliding flap is rotatably connected to the upper end of the connecting cylinder through a rotating pin, the lower top cylinder is below the limiting cylinder, and the upper end of the lower top cylinder is connected to the outer wall of the upper top cylinder; A transmission groove is arranged at the upper end of the sliding flap, the shape of the transmission groove is the same as the outer shape of the lower end of the lower top cylinder, the transmission groove inclines towards the central pipe with the rotating pin as the fulcrum, and the lower end of the lower top cylinder contacts the upper end of the transmission groove.

5. The split-type hydraulic full-bore centralizer according to claim 4, characterized in that, Threaded joints are arranged on the upper end inner wall of the cylinder base, and a lower joint is arranged on the lower end inner wall of the central pipe.

6. A split-type hydraulic full-bore centralizer according to claim 5, characterized in that, The outer wall of the cylinder base is a precision-machined sealing surface, at least one first sealing ring groove is arranged on the outer wall of the cylinder base for placing the first sealing ring, a first joint thread is arranged on the upper end inner wall of the cylinder base, a first internal thread is arranged at the lower end, and a conical surface is used for transition between the first joint thread and the first internal thread; The hydraulic cylinder is of a cylindrical structure, and three diameter surfaces of large, small, and medium are successively machined inside the hydraulic cylinder from top to bottom. Among them, the small diameter surface and the large diameter surface are precision-machined sealing surfaces, at least one second sealing ring groove is machined on the small diameter surface for placing the second sealing ring, a second internal thread is machined on the medium diameter surface for connecting with the upper top cylinder, and a nail groove is machined on the corresponding outer wall of the medium diameter surface; The central pipe is of a stepped pipe type structure, a first external thread is arranged at the upper end of the central pipe, a fifth external thread is arranged at the lower end, and a large diameter external thread is machined above the fifth external thread for connecting the connecting cylinder; A fifth internal thread is arranged at the upper end inner wall of the lower joint, a second joint thread is arranged at the lower end, and a conical surface is used for transition between the fifth internal thread and the second joint thread.

7. A split hydraulic full-bore centralizer according to claim 6, wherein, The upper top cylinder has a special-shaped cylindrical structure. The upper end of its outer wall is machined with a second external thread. The outer wall of the upper top cylinder is successively a flat surface, a convex ring, and a conical support surface from top to bottom. The convex ring is machined with a third external thread for connecting with the lower top cylinder. The limiting cylinder is arranged above the convex ring; The upper end inner wall of the lower top cylinder is provided with a third internal thread, and the lower end is machined with an inner conical surface. The lower end of its outer wall is machined with an outer conical surface. The conical surface thickness of the lower top cylinder gradually decreases from top to bottom; The upper end of the limiting cylinder is provided with a limiting step. The lower end outer wall of the limiting cylinder is provided with a fourth external thread for connecting with the outer cylinder; the upper end inner wall of the outer cylinder is machined with a fourth internal thread.

8. A split-type hydraulic full-bore centralizer according to claim 6, characterized in that The lower end of the sliding flap is provided with a first hinge support. A first pin hole is machined in the first hinge support for connecting with the connecting cylinder. The outer wall of the sliding flap is an arc surface; The inner wall of the connecting cylinder is machined with a large-diameter internal thread. The outer wall is provided with a pin socket for pin connection with the lower end of the outer cylinder. The lower end outer wall of the connecting cylinder is provided with an outer cylinder limiting seat. The upper end of the connecting cylinder is provided with a second hinge support. A second pin hole is arranged in the second hinge support; The pin passes through the first pin hole and the second pin hole to complete the rotational connection between the sliding flap and the connecting cylinder.

9. A method for using a split hydraulic full-bore centralizer, characterized in that, It includes the following steps: S1. Pressurize from the wellhead. The pressure passes through the pressure transmission hole to push the hydraulic cylinder downward to store energy for the return spring. The outer conical surface at the lower end of the lower top cylinder enters the transmission groove in the sliding flap. The transmission groove is aligned by the lower top cylinder, and the sliding flap moves outward around the pin, thereby expanding the sliding flap through groove. The arc surface of the outer wall of the sliding flap contacts the inner wall of the casing to achieve centering and straightening; S2. When the hydraulic pressure disappears, the return spring pushes the hydraulic cylinder upward. The inner conical surface at the lower end of the lower top cylinder presses on the upper end of the rotation groove inside the sliding flap, causing the sliding flap to contract back into the outer cylinder and return to its original state.

10. A casing bending well straightening string of a split type hydraulic full gauge centralizer, comprising a tubing string, characterized in that, It further includes a hydraulic anchor, a hydraulic force amplifier, a split-type hydraulic full-bore centralizer, and a variable stiffness shaper connected in sequence from top to bottom. The upper end of the hydraulic anchor is connected to the tubing; The split-type hydraulic full-bore centralizer is provided with a hydraulic mechanism, a lower top cylinder, a sliding flap, and a connecting cylinder; the lower end of the sliding flap is rotationally connected to the connecting cylinder. The upper end of the lower top cylinder is connected to the hydraulic mechanism. The upper end of the sliding flap is provided with a transmission groove that inclines inward with the rotational connection shaft as the center. The lower end of the lower top cylinder contacts the upper end of the transmission groove.

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