Small-outer-diameter hydraulic centralizer for coal bed gas open hole design

Abstract

The utility model discloses a small-outer-diameter hydraulic centralizer for coal bed gas open hole design, and belongs to the technical field of coal mining. The device comprises an outer cylinder, an inner cylinder is arranged in the outer cylinder, an extension guide column flush with the top of the inner cylinder in height is arranged at the top of the outer cylinder, a compression spiral ring surrounding the top of the inner cylinder is arranged on the inner wall of the extension guide column, and multiple sets of centralizing frames in an annular array are arranged on the outer circumferential wall of the outer cylinder. Accurate centralizing and stabilizing are achieved through hydraulic driving, and local difference is avoided; the righting frame and the stabilizing frame are flexible in design and can meet the requirements of different hoistways, the length of the inserting rod is adjustable, and stable insertion is ensured; by means of the spiral flow guide structure and the flow guide conical ring, the resistance of the centralizer to flowing of substances in a well is effectively reduced, and retention, sedimentation and blockage are avoided; the overall operation is simple, convenient and flexible, the fitting adaptability is high, and accurate control can be achieved according to actual requirements.

Description

Technical Field

[0001] The utility model relates to the technical field of coal mining, in particular to a small outer diameter hydraulic centralizer designed for coalbed methane open hole. Background Art

[0002] A centralizer is a rigid yet flexible stabilizing structure typically installed on the outer surface of casing or tubing. Its primary function is to prevent the casing or tubing from shifting or tilting within the wellbore, thereby ensuring the stability and efficiency of mining equipment. Centralizers can be categorized into various types, including mechanical and hydraulic, depending on their structure and function. Coalbed methane openhole wells, defined as sections without casing protection, present additional challenges during mining. Due to the geological characteristics of the coal seam, these sections are prone to collapse and eccentric wear, which not only impact mining efficiency but can also lead to safety incidents. Therefore, the use of centralizers in coalbed methane openhole wells is particularly important.

[0003] In conjunction with the above content, it should be noted that: the Chinese patent with publication number CN208966214U discloses a hydraulic stabilizer and casing for improving the quality of cementing in small-hole side drilling. It increases pressure by injecting liquid into the annular cavity, thereby driving the straightening claws at the bottom of the sliding assembly to open, thereby achieving external support, straightening between the casing and the well wall. However, during actual use, the interior of the small-diameter channel designed for coalbed methane open holes may be affected by the mining process, resulting in local obstructions or depressions, causing defects in the use of the opening support limit of a single set of straightening claws, resulting in insufficient contact or excessive contact in local areas, resulting in certain abnormalities in the straightening angle, and affecting subsequent mining.

[0004] In view of the above technical defects, a solution is now proposed. Utility Model Content

[0005] The purpose of the utility model is to provide a small outer diameter hydraulic centralizer designed for coalbed methane open hole to solve the problems raised.

[0006] The purpose of the utility model can be achieved by the following technical solutions: a small outer diameter hydraulic centralizer designed for coalbed methane open hole, comprising an outer cylinder, an inner cylinder arranged inside the outer cylinder, an extension guide column arranged on the top of the outer cylinder at the same height as the top of the inner cylinder, a compression spiral ring surrounding the top of the inner cylinder arranged on the inner wall of the extension guide column, and multiple groups of centralizer frames arranged in an annular array on the outer peripheral wall of the outer cylinder;

[0007] A plurality of stabilizing frames are arranged on the outer wall of the extension guide column. An inserting rod is slidingly arranged inside the frame body of the stabilizing frame at one end away from the extension guide column. A lifting hydraulic rod connected to the compression spiral ring is embedded on the inner wall of the extension guide column.

[0008] Preferably, multiple groups of lower bins are provided in a circular array depression on the outer wall of the outer cylinder, and a connecting frame is embedded in the center of the lower bin. Each two groups of the straightening frames are symmetrically installed in the top and bottom bin bodies of the lower bin, and the upper and lower ends of the connecting frame are respectively hinged to the two adjacent groups of straightening frames.

[0009] Preferably, an inner push hydraulic rod is embedded in the inner wall of the lower warehouse, a telescopic hydraulic connecting rod is slidably sleeved on the surface of the inner push hydraulic rod, and the other end of the telescopic hydraulic connecting rod is hinged to the inner wall of the straightening frame, and an inner sleeve connected to the inner cylinder is provided on the inner wall of the outer cylinder.

[0010] Preferably, the bottom of the inner cylinder is provided with a guide cone ring sleeved with the bottom of the outer cylinder, and the top of the inner cylinder is provided with a sealing gasket connected with the top of the outer cylinder.

[0011] Preferably, a ring bin which is sleeved with the outer cylinder is provided at the bottom of the extension guide column, and multiple groups of the extension guide columns are arranged in a circular array along the top of the ring bin, an upper bin is recessed on the outer wall of the extension guide column, a limiting shaft is provided at the inner center of the upper bin, and a group of stabilizing frames are hinged at the top and bottom of the limiting shaft.

[0012] Preferably, two inner-pushing hydraulic rods are embedded in the inner wall of the upper warehouse, and two telescopic hydraulic connecting rods are slidably sleeved on the surface of the two inner-pushing hydraulic rods. The bottom of the two telescopic hydraulic connecting rods is hinged to the outer wall of the stabilizing frame, and a propulsion hydraulic rod connected to the insertion rod is embedded inside the stabilizing frame.

[0013] Preferably, a traction ring frame connected to a lifting hydraulic rod is provided on the top of the compression spiral ring.

[0014] Beneficial effects of the utility model:

[0015] The utility model adopts hydraulic medium to drive the inward-pushing hydraulic rod and the telescopic hydraulic connecting rod to achieve the precise deployment of the righting frame and the stabilizing frame, effectively ensuring the stable righting of the outer cylinder in the coalbed methane small-diameter well. The righting frame and the stabilizing frame are spread outward in an eight-shaped shape, and a secondary stable eight-shaped limiting structure is formed, which effectively avoids the righting deviation caused by the unevenness of the local area, and significantly improves the accuracy and stability of the righting. The length of the insertion rod can be flexibly adjusted and selected according to the strength of the soil on the inner wall of the wellbore to adapt to the stable insertion and use under different soil conditions.

[0016] After the lifting hydraulic rod is started, the utility model uses the spiral guide structure composed of the traction ring frame and the compression spiral ring to cooperate with the outer cylinder and the inner cylinder to divide the well into inner and outer double channels. The guide cone ring guides the material diversion, reduces the resistance of the centralizer to the flow of material in the well, and puts an end to the phenomenon of material retention, precipitation and blockage around the centralizer. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described below with reference to the accompanying drawings;

[0018] Figure 1 This is a three-dimensional diagram of the overall structure of the utility model;

[0019] Figure 2 This is a schematic diagram of the internal structure of the outer cylinder of the utility model;

[0020] Figure 3 This is a schematic diagram of the connection structure between the uprighting frame and the outer cylinder of the utility model;

[0021] Figure 4 This is a schematic diagram of the connection structure between the inner cylinder and the outer cylinder of the utility model;

[0022] Figure 5 This is a schematic diagram of the connection structure between the extension guide post and the compression spiral ring of the utility model;

[0023] Figure 6 It is a structural schematic diagram of the utility model stabilizing frame.

[0024] Legend: 1. Outer cylinder; 101. Lower chamber; 102. Righting frame; 103. Connecting frame; 104. Inner kit; 105. Telescopic hydraulic connecting rod 1; 106. Inner push hydraulic rod 1; 2. Inner cylinder; 201. Guide cone ring; 3. Extended guide column; 301. Upper chamber; 302. Stabilizing frame; 303. Ring chamber; 304. Limiting shaft rod; 305. Lifting hydraulic rod; 306. Insertion rod; 4. Compression spiral ring; 401. Traction ring frame. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] Example 1: Please refer to Figure 1 - Figure 6 As shown, this embodiment is a small outer diameter hydraulic straightener designed for coalbed methane open hole, comprising an outer cylinder 1, an inner cylinder 2 is arranged inside the outer cylinder 1, an extension guide column 3 is arranged on the top of the outer cylinder 1 and is flush with the top of the inner cylinder 2, a compression spiral ring 4 is arranged on the inner wall of the extension guide column 3 and surrounds the top of the inner cylinder 2, and multiple groups of straightening frames 102 in a circular array are arranged on the outer peripheral wall of the outer cylinder 1. The outer cylinder 1 enters the small diameter well of the coalbed methane open hole through the cooperation of an external traction member and a hydraulic pipeline, and slides along the inside to the area requiring straightening.

[0027] A plurality of lower bins 101 are provided in a circular array depression on the outer wall of the outer cylinder 1, and a connecting frame 103 is embedded in the center of the lower bin 101. Two groups of righting frames 102 are symmetrically installed in the top and bottom bins of the lower bin 101, and the upper and lower ends of the connecting frame 103 are respectively hinged to the two adjacent groups of righting frames 102. When waiting to reach the designated position, the top of the extended guide column 3 is connected to the hydraulic pipe through an external valve and guides the hydraulic medium to enter. The medium is guided by the pipe fittings and regulating valves pre-embedded in the extended guide column 3 and the outer cylinder 1 to flow into each component that needs to be driven by the hydraulic medium.

[0028] An inner push hydraulic rod 106 is embedded in the inner wall of the lower warehouse 101, and a telescopic hydraulic connecting rod 105 is slidably sleeved on the surface of the inner push hydraulic rod 106, and the other end of the telescopic hydraulic connecting rod 105 is hinged to the inner wall of the straightening frame 102. An inner sleeve 104 connected to the inner cylinder 2 is provided on the inner wall of the outer cylinder 1. Part of the hydraulic medium enters the inner push hydraulic rod 106, and the inner push hydraulic rod 106 drives the telescopic hydraulic connecting rod 105 to slide downward along its surface through related accessories. Related accessories include traditional connection accessories such as couplings, shafts, gaskets, and rotating shafts. They are replaced and connected using related adapter connection methods according to actual needs. They are only used for connecting links between components. The telescopic hydraulic connecting rod 106 At the same time, hydraulic medium is injected into the interior of 105, and its two ends are respectively connected and rotated with the straightening frame 102 and the inner push hydraulic rod 106 through relevant accessories, and then stretched, pushing the straightening frame 102 to rotate. The rotation point is the hinge point of the straightening frame 102 and the connecting frame 103, forming two groups of upper and lower eight-shaped outward expansions until they are attached to the inner wall of the wellbore, realizing the annular upper and lower multi-point coordinated outward expansion contact limit on the outside of the outer cylinder 1, thereby avoiding the straightening difference caused by convexity or concavity in local areas, and the straightening frame 102 is replaced with appropriate materials and shapes according to the actual soil layer inside the wellbore, including single-section support arms and multi-section adjustable hydraulic arms, which are only used to adapt to the wellbore fit and are not limited to the single style shown in the attached drawings.

[0029] The bottom of the inner cylinder 2 is provided with a guide cone ring 201 which is sleeved with the bottom of the outer cylinder 1 , and the top of the inner cylinder 2 is provided with a sealing gasket which is connected with the top of the outer cylinder 1 .

[0030] Example 2: This embodiment is a small outer diameter hydraulic straightener designed for coalbed methane open hole, including multiple groups of stabilizing frames 302 arranged on the outer wall of the extension guide column 3, and an insert rod 306 is slidingly arranged inside the frame body of the stabilizing frame 302 away from the extension guide column 3, and a lifting hydraulic rod 305 connected to the compression spiral ring 4 is embedded on the inner wall of the extension guide column 3.

[0031] An annular bin 303 which is sleeved with the outer cylinder 1 is provided at the bottom of the extension guide column 3. Multiple groups of extension guide columns 3 are arranged in an annular array along the top of the annular bin 303. An upper bin 301 is recessed on the outer wall of the extension guide column 3. A limiting shaft rod 304 is provided at the inner center of the upper bin 301. A group of stabilizing frames 302 are hinged at the top and bottom of the limiting shaft rod 304.

[0032] The inner wall of the upper warehouse 301 is embedded with an inner push hydraulic rod 2, and the surface of the inner push hydraulic rod 2 is slidably sleeved with a telescopic hydraulic connecting rod 2, the bottom of the telescopic hydraulic connecting rod 2 is hinged to the outer wall of the stabilizing frame 302, and the inside of the stabilizing frame 302 is embedded with a propulsion hydraulic rod connected to the insertion rod 306, and the top of the compression spiral ring 4 is provided with a traction ring frame 401 connected to the lifting hydraulic rod 305. The inner push hydraulic rod 2 in the upper warehouse 301 is started by the hydraulic medium, and the inner push hydraulic rod 2 drives the telescopic hydraulic connecting rod 2 to slide down through the relevant accessories, and the telescopic hydraulic connecting rod 2 is started by the hydraulic medium. The stabilizing frame 302 is extended, thereby driving the two groups of stabilizing frames 302 in the upper warehouse 301 to deflect along the limiting shaft 304 until the stabilizing frame 302 contacts the inner wall of the well, forming a secondary stable eight-shaped limiting structure above the outer cylinder 1, and according to actual needs, the hydraulic rod is driven by the hydraulic medium, thereby driving the insertion rod 306 to slide out along the end face of the stabilizing frame 302 and insert into the inner wall of the well in contact with the stabilizing frame 302. The length of the insertion rod 306 is adjusted according to the strength of the soil on the inner wall of the well, and is optional and is only used when the strength of the inner wall of the well is not affected by the insertion.

[0033] The lifting hydraulic rod 305 is started by the hydraulic medium, which drives the traction ring frame 401 to slide upward along the extension guide column 3 axis through related accessories, until the traction ring frame 401 drives the compression spiral ring 4 to expand, until the top part of the compression spiral ring 4 expands upward from the ring warehouse 303, and then forms a spiral guide structure on the outer periphery of the inner cylinder 2, which is used to cooperate with the outer cylinder 1 and the inner cylinder 2 to divide the inside of the wellbore into inner and outer double channels, and guide the material diversion through the guide cone ring 201 to reduce the resistance of the stabilizer to the flow of material along the wellbore. At the same time, when the material flows along the outer wall of the outer cylinder 1 through the compression spiral ring 4, the compression spiral ring 4 is used to guide the material to flow along its internal fixed trajectory, thereby causing the flow trajectory of part of the material to change, effectively avoiding the retention, precipitation and blockage of the material around the stabilizer.

[0034] In combination with Example 1 and Example 2, precise straightening and stabilization are achieved through hydraulic drive to avoid local differences; the straightening frame 102 and the stabilizing frame 302 are flexibly designed to adapt to different wellbore requirements, and the length of the insertion rod 306 is adjustable to ensure stable insertion; the spiral guide structure and the guide cone ring 201 are used to effectively reduce the resistance of the straightener to the flow of materials in the wellbore, avoiding retention, precipitation and blockage; the overall operation is simple and flexible, the accessories are highly adaptable, and can be precisely controlled according to actual needs. These characteristics jointly improve the efficiency and safety of coalbed methane extraction and provide efficient technical support for related operations.

[0035] The above content is merely an example and explanation of the structure of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in a similar manner. As long as they do not deviate from the structure of the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

[0036] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0037] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to specific embodiments. Obviously, many modifications and variations are possible based on the contents of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A small outer diameter hydraulic centralizer designed for coalbed methane open hole, comprising an outer cylinder (1), characterized in that: An inner cylinder (2) is arranged inside the outer cylinder (1), an extension guide column (3) is arranged on the top of the outer cylinder (1) and is flush with the top of the inner cylinder (2), a compression spiral ring (4) surrounding the top of the inner cylinder (2) is arranged on the inner wall of the extension guide column (3), and multiple groups of straightening frames (102) in a circular array are arranged on the outer peripheral wall of the outer cylinder (1); multiple groups of stabilizing frames (302) are arranged on the outer wall of the extension guide column (3), and an insertion rod (306) is slidably arranged inside the frame body of the stabilizing frame (302) at one end away from the extension guide column (3), and a lifting hydraulic rod (305) connected to the compression spiral ring (4) is embedded on the inner wall of the extension guide column (3).

2. The small outer diameter hydraulic centralizer for coalbed methane open hole design according to claim 1 is characterized in that: A plurality of lower bins (101) are provided in a circular array depression on the outer wall of the outer cylinder (1), and a connecting frame (103) is embedded in the center of the lower bin (101). Two groups of the righting frames (102) are symmetrically installed in the top and bottom bins of the lower bin (101), and the upper and lower ends of the connecting frame (103) are respectively hinged to the two adjacent groups of righting frames (102).

3. The small outer diameter hydraulic centralizer for coalbed methane open hole design according to claim 2, characterized in that: An inner push hydraulic rod (106) is embedded in the inner wall of the lower bin (101), a telescopic hydraulic connecting rod (105) is slidably sleeved on the surface of the inner push hydraulic rod (106), and the other end of the telescopic hydraulic connecting rod (105) is hinged to the inner wall of the straightening frame (102), and an inner sleeve (104) connected to the inner cylinder (2) is provided on the inner wall of the outer cylinder (1).

4. The small outer diameter hydraulic centralizer for coalbed methane open hole design according to claim 1 is characterized in that: The bottom of the inner cylinder (2) is provided with a guide cone ring (201) sleeved with the bottom of the outer cylinder (1), and the top of the inner cylinder (2) is provided with a sealing gasket connected with the top of the outer cylinder (1).

5. The small outer diameter hydraulic centralizer for coalbed methane open hole design according to claim 1, characterized in that: The bottom of the extension guide column (3) is provided with a ring warehouse (303) sleeved with the outer cylinder (1), and the extension guide column (3) is arranged in a ring array along the top of the ring warehouse (303) in multiple groups. An upper warehouse (301) is recessed on the outer wall of the extension guide column (3), and a limiting shaft (304) is provided at the center of the upper warehouse (301). The top and bottom of the limiting shaft (304) are both hinged with a group of stabilizing frames (302).

6. The small outer diameter hydraulic centralizer for coalbed methane open hole design according to claim 5, characterized in that: Two inner push hydraulic rods are embedded in the inner wall of the upper warehouse (301), and two telescopic hydraulic connecting rods are slidably sleeved on the surface of the second inner push hydraulic rod. The bottom of the second telescopic hydraulic connecting rod is hinged to the outer wall of the stabilizing frame (302), and a propulsion hydraulic rod connected to the insertion rod (306) is embedded in the interior of the stabilizing frame (302).

7. The small outer diameter hydraulic centralizer for coalbed methane open hole design according to claim 1, characterized in that: A traction ring frame (401) connected to a lifting hydraulic rod (305) is provided on the top of the compression spiral ring (4).

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