Pressure controlled centralizer

Abstract

The application provides a pressure control type centralizer and belongs to the technical field of centralizers. The centralizer comprises a centralizer main body, a locking sleeve is threadedly installed at one end of the inside of the centralizer main body, a plug is threadedly installed at the other end of the inside of the centralizer main body, a communication channel is arranged in the inner wall of the centralizer main body, the inner cavity of the centralizer main body between the locking sleeve and the plug is respectively provided with a support plate, the center of the support plate is provided with a sliding hole, a sliding rod is slidably arranged in the sliding hole, an elastic reset member is sleeved on the sliding rod, a piston head is arranged at the outer end of the sliding rod, the inner end of the sliding rod is in the shape of a polygonal prism, and a rack is arranged on at least two edge surfaces of the sliding rod, a long slot hole is arranged on the centralizer main body opposite to each rack, and one support rod is hingedly arranged at each end of the inside of each long slot hole. The application effectively avoids the problem of increased drilling resistance caused by the arc-shaped centralizing piece being located outside the drill rod, and can adjust the adhesion degree of the centralizing rod and the hole wall by adjusting the pressure of the high-pressure medium.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of centralizers, in particular to a pressure control type centralizer. BACKGROUND

[0002] Most of the existing centralizers are tensionless alloy centralizers, such as the utility model patent with the authorized announcement number CN2493736Y discloses a drillable centralizer for oil field cementing, which mainly includes two end couplings and a plurality of arc-shaped centralizing pieces fixedly arranged between the two couplings, the whole is similar to a sugar cane in shape, the centralizer is not subjected to extrusion in the axial direction during normal drilling, and all the arc-shaped centralizing pieces are in a state of initial small bending, when the drilling direction needs to be adjusted during drilling, the centralizer is subjected to extrusion in the axial direction, so that the arc-shaped centralizing pieces bulge outward to support the hole wall.

[0003] However, the tensionless alloy centralizer is sleeved on the drill pipe, even during normal drilling when the arc-shaped centralizing pieces are not extruded and bulged, the arc-shaped centralizing pieces are still located on the outside of the drill pipe, which will inevitably increase the diameter of the drill pipe, and in turn increase the drilling resistance of the drill pipe; at the same time, when the arc-shaped centralizing pieces support the hole wall, the stress points are concentrated near the outermost bending points of the arc-shaped centralizing pieces, which results in limited contact area between the arc-shaped centralizing pieces and the hole wall, and cannot guarantee that the arc-shaped centralizing pieces are tightly fitted with the inner wall of the borehole. SUMMARY

[0004] Therefore, the present application provides a pressure control type centralizer, when turning, the centralizer rod can be completely withdrawn into the corresponding long slot hole, effectively avoiding the problem of increased drilling resistance caused by the arc-shaped centralizing pieces located on the outside of the drill pipe; when rotary drilling, the high-pressure medium pushes the piston heads on both sides to move towards each other, and then the centralizer rod opens and tightens the hole wall through the cooperation of the rack and the teeth, which can not only reduce the deviation generated during drilling, but also adjust the fitting degree of the centralizer rod and the hole wall by adjusting the pressure of the high-pressure medium.

[0005] To solve the above technical problems, the application provides a pressure control type centralizer, which comprises a cylindrical centralizer body, a locking sleeve threadedly installed at one end of the inner part of the centralizer body, a plug threadedly installed at the other end of the inner part of the centralizer body, a communication channel arranged in the inner wall of the centralizer body and used for communicating and balancing the pressure between the inner cavity of the locking sleeve and the inner cavity of the plug, one support plate arranged in the inner cavity of the centralizer body between the locking sleeve and the plug, a sliding hole arranged in the center of the support plate, a sliding rod slidingly arranged in the sliding hole, an elastic reset member sleeved on the sliding rod, a piston head arranged at the outer end of the sliding rod, the piston head being pushed by high-pressure medium entering the communication channel along the locking sleeve, the inner end of the sliding rod being in the shape of a polygonal prism and at least two edges of the polygonal prism being provided with a rack, a long slot hole being arranged in the centralizer body opposite to each rack, and each long slot hole being hingedly connected with one support rod at both ends of the inner part of the long slot hole, the hinged end of the support rod being provided with a toothed portion matched with the rack, and the other ends of the two support rods in the same long slot hole being connected with a centralizing rod through a connecting shaft.

[0006] The centralizing rod is accommodated in the long slot hole in the manner that the long slot hole is arranged in the centralizer body, so that the centralizing rod is retracted into the long slot hole when steering is needed and is extended to be attached to the hole wall when rotary drilling is performed. Specifically, a sliding slot hole is arranged at both ends of the centralizing rod, one support rod is hingedly connected at both ends of the inner part of the long slot hole, and the outer ends of the two support rods in the same long slot hole are connected with both ends of the centralizing rod through a connecting shaft, the connecting shaft being fixedly arranged at the end of the support rod and being capable of sliding in the corresponding sliding slot hole. Meanwhile, the extension and retraction of the centralizing rod are achieved by the pushing of high-pressure medium, specifically, a communication channel is arranged in the inner wall of the centralizer body and used for communicating and balancing the pressure between the inner cavity of the locking sleeve and the inner cavity of the plug. During rotary drilling, the pressure between the inner cavity of the locking sleeve and the inner cavity of the plug is communicated and balanced by the communication channel, the high-pressure medium entering the locking sleeve pushes the piston heads on both sides to move towards each other, and then the centralizing rod is opened to support and tighten the hole wall through the matching of the rack and the toothed portion, so as to reduce the deviation during drilling. Meanwhile, the degree of attachment of the centralizing rod to the hole wall can be adjusted according to the actual working condition by adjusting the pressure of the high-pressure medium. When steering is needed, the supply of high-pressure medium is stopped, the piston heads on both sides are restored to the original position under the elastic force of the elastic reset member, and then the centralizing rod is retracted into the corresponding long slot hole, so that the problem of increased drilling resistance caused by the arc-shaped centralizing piece located outside the drill rod can be effectively avoided.

[0007] As a further improvement of the application, the elastic reset member is a reset spring or a rubber sleeve.

[0008] As a further improvement of the application, the inner end of the sliding rod is in the shape of a triangular prism, a quadrangular prism, a pentagonal prism or a hexagonal prism.

[0009] As a further improvement of the present application, the high-pressure medium is high-pressure water or high-pressure gas.

[0010] As a further improvement of the present application, in order to provide a limit for the outer end of the piston head on one side of the plug, while reserving a pressure cavity, the plug is provided with a limit protrusion on the inner end.

[0011] As a further improvement of the present application, in order to limit the outer side of the tooth part on the outermost end, a limit block is provided on the outer side of the hole wall at both ends of the long slot hole.

[0012] As a further improvement of the present application, in order to seal the circumferential surface of the piston head, a first sealing ring is installed on the circumferential surface of the piston head.

[0013] As a further improvement of the present application, in order to seal the circumferential surface of the plug, a second sealing ring is installed on the circumferential surface of the plug.

[0014] In summary, the present application has at least one of the following beneficial technical effects compared with the prior art:

[0015] 1. When steering is needed, the centralizer rod can be completely withdrawn into the corresponding long slot hole, effectively avoiding the problem of increased drilling resistance caused by the arc-shaped centralizer plate located on the outer side of the drill rod; when rotary drilling, the high-pressure medium pushes the piston heads on both sides to move towards each other, and then through the cooperation of the rack and the tooth part, the centralizer rod opens the hole wall, which can not only reduce the deviation during drilling, but also adjust the fitting degree of the centralizer rod and the hole wall by adjusting the pressure of the high-pressure medium.

[0016] 2. After using the technical scheme of the present application, when rotary drilling, the high-pressure medium entering through the locking nut communicates and balances the pressure between the inner cavity of the locking nut and the inner cavity of the plug, the high-pressure medium entering through the locking nut pushes the piston heads on both sides to move towards each other, and then through the cooperation of the rack and the tooth part, the centralizer rod opens the hole wall to reduce the deviation during drilling; when steering is needed, stop supplying the high-pressure medium, the piston heads on both sides return to the original position under the elastic force of the elastic return member, and then the centralizer rod is withdrawn into the corresponding long slot hole. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 Fig. 3 is a structural schematic view of the pressure control type centralizer of the present application when steering;

[0018] Figure 2 Fig. 4 is a structural schematic view of the pressure control type centralizer of the present application when normal drilling;

[0019] REFERENCE NUMERALS:

[0020] 100, centralizer body;

[0021] 101, locking nut;

[0022] 102, plug;

[0023] 103, communication channel;

[0024] 104, support plate;

[0025] 105, sliding hole;

[0026] 106, sliding rod;

[0027] 107, elastic reset member;

[0028] 108, piston head;

[0029] 109, rack;

[0030] 110, long slot hole;

[0031] 111, support rod;

[0032] 112, tooth part;

[0033] 113, connecting shaft;

[0034] 114, centralizer;

[0035] 115, sliding groove hole;

[0036] 116, limit bump;

[0037] 117, limit block;

[0038] 118, first sealing ring;

[0039] 119, second sealing ring. DETAILED DESCRIPTION

[0040] To make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the following will combine the drawings of the embodiments of the present application to further describe the embodiments of the present application in detail. Figure 1 and 2 The technical solutions of the embodiments of the present application are described clearly and completely. Obviously, the described embodiments are part of the embodiments of the present application, not all the embodiments. Based on the described embodiments of the present application, all other embodiments obtained by those skilled in the art belong to the scope of protection of the present application.

[0041] As Figure 1 and Figure 2The pressure control type centralizer shown in the figure mainly comprises a cylindrical centralizer body 100, a locking sleeve 101 is threadedly installed at one end inside the centralizer body 100, and a plug 102 is threadedly installed at the other end inside the centralizer body 100, a communication channel 103 is arranged in the inner wall of the centralizer body 100, for communicating and balancing the pressure between the inner cavity of the locking sleeve 101 and the inner cavity of the plug 102, a support plate 104 is arranged in the inner cavity of the centralizer body 100 between the locking sleeve 101 and the plug 102, the center of the support plate 104 is provided with a sliding hole 105, a sliding rod 106 is slidably arranged in the sliding hole 105, an elastic reset member 107 is sleeved on the sliding rod 106, a piston head 108 is arranged at the outer end of the sliding rod 106, the piston head 108 is pushed by the high-pressure medium entering the communication channel 103 from the locking sleeve 101, the inner end of the sliding rod 106 is in the shape of a polygonal prism, and at least two edges of the polygonal prism are provided with a rack 109, a long slot hole 110 is arranged in the centralizer body 100 opposite to each rack 109, a support rod 111 is hingedly arranged at both ends inside each long slot hole 110, a tooth portion 112 matched with the rack 109 is arranged at the hinged end of the support rod 111, and the other ends of the two support rods 111 in the same long slot hole 110 are connected by a connecting shaft 113, and a centralizing rod 114 is connected between the other ends of the two support rods 111 through the connecting shaft 113.

[0042] When drilling in the coal seam or the bottom drainage roadway, the high-pressure medium supplied by the water supply device pushes the left piston head to drive the rack to move to the right, the right piston head drives the rack to form a balanced pressure with the left end through the communication channel, and the rack is pushed to move to the left, and the matched centralizing rod is opened at the same time to tightly support the hole wall, so as to reduce the deviation during drilling. When turning, stop supplying the medium, at this time, the tension of the elastic reset member is greater than the pressure of the medium. The left and right piston heads drive the racks to return to the original position under the tension of the elastic reset member, and the centralizing rod is retracted into the long slot hole, thereby effectively avoiding the problem of increased drilling resistance caused by the arc-shaped centralizing piece located outside the drill rod; when rotary drilling, the high-pressure medium pushes the piston heads on both sides to move towards each other, and then the centralizing rod is opened to tightly support the hole wall through the cooperation of the rack and the tooth portion, which can not only reduce the deviation generated during drilling, but also adjust the fitting degree of the centralizing rod and the hole wall by adjusting the pressure of the high-pressure medium.

[0043] In addition, the elastic reset member 107 is a reset spring. Obviously, the elastic reset member 107 is not limited to a reset spring, but can also be other types of elastic reset members, such as a rubber sleeve.

[0044] In addition, the inner end of the slide rod 106 is in the shape of a triangular prism, and obviously, the shape of the inner end of the slide rod 106 is not limited to a triangular prism, but can also be in the shape of a quadrangular prism, a pentagonal prism, a hexagonal prism, etc.

[0045] In addition, the high-pressure medium is high-pressure water, the pressure of which can be provided by a water supply or a hole-bottom motor, and the high-pressure medium is used to provide pressure for the extension of the centralizer rod 114 so as to facilitate the adhesion of the centralizer rod 114 to the hole wall, and obviously, the high-pressure medium is not limited to high-pressure water, but can also be other types of fluid, such as high-pressure gas, which can also play the same role.

[0046] In addition, as shown in Figure 1 and Figure 2 , the inner end of the plug 102 is provided with a limiting protrusion 116, and after the plug 102 adopts the above structure, the outer end surface of the piston head 108 on one side of the plug 102 can be limited, and after the piston head 108 is limited by the limiting protrusion 116, a cavity is still left between the plug 102 and the piston head 108, so that the high-pressure medium entering the communication channel 103 from the locking sleeve 101 next time can again smoothly reach the cavity between the plug 102 and the piston head 108.

[0047] In addition, as shown in Figure 1 and Figure 2 , limiting blocks 117 are arranged on the outer sides of the hole walls at both ends of the long slot hole 110 to limit the outer side of the outermost tooth portion 112, so that when the centralizer rod 114 adheres to the hole wall, the outer side of the outermost tooth portion of the support rod 111 can be limited.

[0048] In addition, as shown in Figure 1 and Figure 2 , in order to increase the sealing between the piston head 108 and the inner cavity wall of the centralizer body 100, a first sealing ring 118 is installed on the circumferential surface of the piston head 108; at the same time, in order to increase the sealing between the plug 102 and the inner cavity wall of the centralizer body 100, a second sealing ring 119 is installed on the circumferential surface of the plug 102.

[0049] The above describes the preferred embodiments of the present application, and it should be pointed out that for ordinary skilled persons in the technical field, some improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A pressure-controlled centralizer, comprising a cylindrical centralizer body (100), characterized in that: A locking screw sleeve (101) is threadedly installed at one end of the interior of the centralizer body (100) and a plug (102) is threadedly installed at the other end of the interior. A connecting channel (103) is provided in the inner wall of the centralizer body (100) for connecting and balancing the pressure between the inner cavity of the locking screw sleeve (101) and the inner cavity of the plug (102). A support plate (104) is provided in the inner cavity of the centralizer body (100) between the locking screw sleeve (101) and the plug (102). The center of the support plate (104) has a sliding hole (105). A sliding rod (106) is slidably provided in the sliding hole (105). An elastic reset member (107) is sleeved on the sliding rod (106). A piston head (108) is provided at the outer end of the sliding rod (106). The plug (108) is pushed by a high-pressure medium that enters the connecting channel (103) along the locking screw sleeve (101). The inner end of the sliding rod (106) is in the shape of a polygonal prism and a rack (109) is provided on at least two of its edges. A long slot hole (110) is provided on the stabilizer body (100) opposite to each rack (109). A support rod (111) is hinged at both ends of the inner side of each long slot hole (110). The hinged end of the support rod (111) is provided with a tooth portion (112) that matches the rack (109). The other ends of the two support rods (111) in the same long slot hole (110) are connected to a straightening rod (114) through a connecting shaft (113). The two ends of the straightening rod (114) are provided with a sliding slot hole (115) for installing the same-end connecting shaft (113).

2. The pressure-controlled centralizer according to claim 1, wherein: The elastic reset member (107) is a reset spring or a rubber sleeve.

3. The pressure-controlled centralizer according to claim 1, wherein: The inner end of the sliding rod (106) is in the shape of a triangular prism, or a quadrangular prism, or a pentagonal prism, or a hexagonal prism.

4. The pressure-controlled centralizer according to claim 1, wherein: The high-pressure medium is high-pressure water or high-pressure gas.

5. The pressure-controlled centralizer according to claim 1, wherein: The inner end of the plug (102) is provided with a limiting protrusion (116).

6. The pressure-controlled centralizer according to any one of claims 1 to 5, characterized in that: Limit blocks (117) are provided on the outer sides of the hole walls at both ends of the long slot hole (110) for limiting the outer side of the tooth portion (112) at the outermost end.

7. The pressure-controlled centralizer according to any one of claims 1 to 5, characterized in that: A first sealing ring (118) is installed on the circumferential surface of the piston head (108).

8. The pressure-controlled centralizer according to any one of claims 1 to 5, characterized in that: A second sealing ring (119) is installed on the circumferential surface of the plug (102).

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