Self-adaptive casing centralizer for well drilling

Abstract

The invention relates to the technical field of centralizers, in particular to a self-adaptive casing centralizer for well drilling, which comprises outer pipes and centralizing mechanisms, rotating sliding grooves are formed in the outer ring walls of the two outer pipes, rotating rings are rotatably connected in the two rotating sliding grooves, a plurality of centralizing mechanisms are arranged and arranged between the two rotating rings, and the centralizing mechanisms are arranged on the outer ring walls of the two outer pipes. The straightening mechanisms are distributed in an equiangular mode, each straightening mechanism comprises a first rotating plate, a second rotating plate, a bent plate and a straightening rod of an arc-shaped structure, and a plurality of protruding blocks are arranged on the outer wall of the outer pipe. When a casing pipe enters a drilling well, under the condition that the casing pipe makes contact with protrusions on the inner wall of the drilling well, the righting mechanism is driven by the rotating ring to rotate, meanwhile, the righting mechanism is driven by the first rotating plate to rotate and incline, the righting mechanism is made to give way to the protrusions under the action of rotation and deflection, and the casing pipe can conveniently pass through; the problem that a rigid centralizer fixedly installed on a casing pipe is clamped by the inner wall of a drilled well is solved.

Description

Technical Field

[0001] This invention relates to the field of centralizer technology, and more particularly to an adaptive casing centralizer for drilling. Background Technology

[0002] Casing centralizers are stabilizing tools used in oil drilling. By installing them on the casing string, they improve the centering effect of the casing as it moves into the well, reduce the friction between the casing and the well wall, and facilitate the smooth insertion of the casing into the well.

[0003] Rigid centralizers are generally one-piece structures, fixedly installed on the outer wall of the casing string. When the well wall experiences radial indentation or when the casing moves to a narrow section of the drilling diameter, the rigid centralizer can get stuck. As it continues to move, it will collide with the well wall, resulting in poor casing lowering performance. If an elastic centralizer is used, the bottom of the elastic centralizer will deform during the horizontal lowering of the casing into the well, causing the casing to be in the lower middle part of the centralizer. This makes it difficult to maintain good rigid support for the casing and adapt to changes in the well wall during operation. Summary of the Invention

[0004] The purpose of this invention is to solve the problems in the prior art, and to propose an adaptive casing centralizer for drilling.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: an adaptive casing centralizer for drilling, comprising an outer tube and a centralizing mechanism, wherein two outer tubes are provided, and a rotating groove is provided on the outer ring wall of each of the two outer tubes, and a rotating ring is rotatably connected in each of the two rotating grooves, and the rotating ring in each of the two rotating grooves extends out of the rotating groove; a plurality of centralizing mechanisms are provided, and the plurality of centralizing mechanisms are arranged between the two rotating rings. The aforementioned straightening mechanisms are distributed at equal angles. Each straightening mechanism includes a rotating plate one, a rotating plate two, a bending plate, and a straightening rod with an arc-shaped structure. Several protrusions are provided on the outer wall of the outer tube. The protrusions are integrally formed with the outer tube. A groove is provided on one side of the protrusion. The end of the groove passes through the surface of the protrusion on the side away from the axis of the outer tube. The rotating plate one is hinged in the groove. The rotating plate two is hinged on the side of the rotating plate one away from the groove. The bending plate is hinged on the rotating plate two. An adjusting groove is provided on the inner side wall of the straightening rod. An adjusting slider is slidably connected in the adjusting groove.

[0006] In the aforementioned adaptive casing centralizer for drilling, an inner tube is provided between the two outer tubes, and several equiangularly distributed connecting pieces are provided between any outer tube and the inner tube, with the two ends of any connecting piece welded to the outer walls of the outer tube and the inner tube, respectively.

[0007] In the aforementioned adaptive casing centralizer for drilling, the two grooves within the same centralizing mechanism are opened in opposite directions, there are two adjusting grooves for the centralizing rod within the same centralizing mechanism, and there are two bending plates within the same centralizing mechanism. The two bending plates are installed in opposite directions, and the bending plates correspond one-to-one with the adjusting grooves. One end of each of the two bending plates is slidably connected to the adjusting groove via an adjusting slider.

[0008] In the aforementioned adaptive casing centralizer for drilling, several spring sleeves are fixedly installed on the outer wall of the inner tube, and spring rods are inserted into the spring sleeves. The spring rods correspond one-to-one with the centralizer rods. The end of the spring rod away from the spring sleeve extends out of the spring sleeve and is hinged to the inner side wall of the centralizer rod. A spring is provided inside the spring sleeve.

[0009] In the aforementioned adaptive casing centralizer for drilling, two symmetrical through slots are provided on the outer wall of any of the spring sleeves, and a ring-shaped slot is provided on the spring rod inside any of the spring sleeves. A connector is provided on the slot, and the two ends of the connector extend out of the through slot and are slidably provided with synchronous sleeves. A slide rod is fixedly installed between any two spring sleeves and on the outer wall of the inner tube. An H-shaped connector is slidably provided on the slide rod, and the connector is hinged to one end of the connector on the two adjacent spring sleeves.

[0010] In the aforementioned adaptive casing centralizer for drilling, an arc-shaped spring groove is provided in the middle of any of the centralizing rods, and the two ends of the spring groove are respectively connected to the adjusting slides on both sides. A second spring is provided in the spring groove.

[0011] In the aforementioned adaptive casing centralizer for drilling, an arc-shaped slot is provided inside any of the centralizing rods, with the two ends of the slot penetrating both ends of the centralizing rod. Elastic baffles are fixedly installed on the two rotating plates within the same centralizing mechanism, and the two elastic baffles are inserted into their respective slots.

[0012] In the aforementioned adaptive casing centralizer for drilling, each of the two rotating plates on the centralizing mechanism is fixedly equipped with elastic ropes for resetting the rotating plates. The side of the two elastic ropes away from the rotating plates is fixedly installed on the outer wall of the corresponding outer casing, and the installation directions of the two elastic ropes are opposite.

[0013] Compared with existing technologies, the advantages of this invention are: 1. This invention designs a rotating ring and a centralizing mechanism. When the casing enters the well, upon contacting the protrusion on the inner wall of the well, the rotating ring drives the centralizing mechanism to rotate. At the same time, the rotating plate drives the centralizing mechanism to rotate and tilt, so that the centralizing mechanism makes way for the protrusion under the action of rotation and deflection, making it easier for the casing to pass through. This solves the problem of the rigid centralizer fixedly installed on the casing being stuck on the inner wall of the well.

[0014] 2. This invention designs a spring sleeve and a spring rod. When moving to a wide diameter, the spring sleeve and spring rod drive the centralizing rod to expand radially, so that the centralizing rod continuously contacts the inner wall of the well. When moving to a narrow diameter, the centralizing rod is squeezed by the inner wall of the well, which drives the centralizing mechanism to contract radially, so that the centralizing mechanism can self-adjust and maintain the casing to move smoothly in the well while producing a centering effect.

[0015] 3. The present invention designs connector one and connector two. When any straightening mechanism moves radially, connector one and connector two drive all straightening mechanisms to move radially synchronously, thereby keeping the sleeve always in the center of the straightener and maintaining the centering effect of the sleeve very well. Attached Figure Description

[0016] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0017] Figure 2 This is the invention Figure 1 A magnified schematic diagram of the structure at point A in the middle.

[0018] Figure 3 This is the invention Figure 1 A magnified schematic diagram of the structure at point B in the middle.

[0019] Figure 4 This is a cross-sectional structural diagram of the present invention.

[0020] Figure 5 This is the invention Figure 4 A magnified schematic diagram of the structure at point C.

[0021] Figure 6 This is the invention Figure 4 A magnified schematic diagram of the structure at point D.

[0022] Figure 7 This is the invention Figure 4 A magnified schematic diagram of the structure at point E in the middle.

[0023] Figure 8 This is a cross-sectional structural schematic diagram of the inner tube of the present invention.

[0024] Figure 9 This is the invention Figure 8 A magnified schematic diagram of the structure at point F in the middle.

[0025] Figure 10 This is a three-dimensional structural diagram of the rotating plate II of the present invention.

[0026] Figure 11 This is a partial three-dimensional structural schematic diagram of the present invention.

[0027] In the diagram: 1. Outer tube; 11. Rotating groove; 12. Rotating ring; 13. Protrusion; 14. Groove; 2. Rotating plate one; 21. Rotating plate two; 3. Bending plate; 4. Straightening rod; 41. Adjusting groove; 42. Adjusting slider; 43. Spring groove; 44. Spring two; 45. Slot; 46. Elastic baffle; 5. Inner tube; 6. Connecting piece; 51. Spring sleeve; 52. Spring rod; 53. Spring one; 54. Through groove; 55. Slot; 7. Connector one; 71. Synchronizing sleeve; 8. Slide rod; 81. Connector two; 9. Elastic rope. Detailed Implementation

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0029] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0030] Reference Figures 1-11An adaptive casing centralizer for drilling includes an outer casing 1 and a centralizing mechanism. Two outer casings 1 are provided, each with a rotating groove 11 on its outer annular wall. A rotating ring 12 is rotatably connected within each of the two rotating grooves 11, and the rotating rings 12 extend beyond the grooves 11. Several centralizing mechanisms are provided, positioned between the two rotating rings 12 and distributed at equal angles. Each centralizing mechanism includes a first rotating plate 2, a second rotating plate 21, a bending plate 3, and an arc-shaped centralizing rod 4. Several protrusions 13 are provided on the outer wall of the outer casing 1, forming an integral structure with the outer casing 1. A groove 14 is formed on one side of each protrusion 13, with its end penetrating the surface of the protrusion 13 away from the axis of the outer casing 1. The first rotating plate 2 is hinged within the groove 14, the second rotating plate 21 is hinged on the side of the first rotating plate 2 away from the groove 14, and the bending plate 3 is hinged to the second rotating plate 2. On the upper part, the inner wall of the straightening rod 4 is provided with an adjusting groove 41, and an adjusting slider 42 is slidably connected in the adjusting groove 41. The straightening rod 4 contacts the inner wall of the well to straighten the casing. When the inner wall of the well deforms due to stress and is concave towards the axis, the straightening mechanism can be driven to rotate around the rotating ring 12 under the action of the rotating ring 12, so that the straightening mechanism is disengaged from the concave area. At the same time, the other straightening mechanisms still maintain the supporting force on the casing, thereby centering the casing. When the protrusion at a certain part of the inner wall of the well is large, the pressure generated on any one of the straightening rods 4 is large. At this time, the straightening rod 4 can be tilted, thereby driving the bending plate 3 to rotate. In order to maintain the connection effect between the straightening rod 4 and the bending plate 3 through the adjusting groove 41, the bending plate 3 is rotated in opposite directions through the two rotating plates 2 in the same straightening mechanism, driving the bending plate 3 and the straightening mechanism to tilt and rotate as a whole, making way for the protrusion of the inner wall, which facilitates the lowering of the casing.

[0031] An inner tube 5 is provided between two outer tubes 1. Several connecting pieces 6 are provided between any outer tube 1 and inner tube 5 at equal angles. The two ends of any connecting piece 6 are welded to the outer walls of the outer tube 1 and the inner tube 5, respectively. The inner tube 5 and the connecting pieces 6 are used to connect the two outer tubes 1.

[0032] The two grooves 14 within the same straightening mechanism are opened in opposite directions. There are two adjusting grooves 41 for the straightening rod 4 within the same straightening mechanism. There are two bending plates 3 within the same straightening mechanism. The two bending plates 3 are installed in opposite directions. The bending plates 3 correspond one-to-one with the adjusting grooves 41. One end of each of the two bending plates 3 is slidably connected to the adjusting grooves 41 through adjusting sliders 42. When the inner diameter of the well changes, the straightening rod 4 moves radially, causing the two adjusting sliders 42 to move together. Furthermore, the adjusting sliders 42 pull the corresponding bending plates 3 to move, so that the straightening mechanism can keep the casing in the middle of the straightener according to the change of the inner diameter of the well.

[0033] Several spring sleeves 51 are fixedly installed on the outer wall of the inner tube 5. Spring rods 52 are inserted into the spring sleeves 51. The spring rods 52 correspond one-to-one with the centralizing rods 4. The end of the spring rod 52 away from the spring sleeve 51 extends out of the spring sleeve 51 and is hinged to the inner wall of the centralizing rod 4. A spring 53 is installed inside the spring sleeve 51. In the initial state, the centralizing mechanism is in the narrowest diameter state of the drilling. When the centralizer moves to the wide diameter, the spring rod 52 is driven to move radially outward through the spring 53, which in turn drives the several centralizing rods 4 to expand radially outward. Through the hinge between the spring rod 52 and the centralizing rod 4, when the protrusion at a certain point on the inner wall of the drilling is large, it is convenient for the centralizing rod 4 to produce a tilting yielding effect.

[0034] Two symmetrical through slots 54 are formed on the outer wall of any spring sleeve 51. A ring-shaped groove 55 is formed on the spring rod 52 inside any spring sleeve 51. A connector 7 is provided on the groove 55. Both ends of the connector 7 extend out of the through slots 54 and are slidably fitted with synchronous sleeves 71. A slide rod 8 is fixedly installed between any two spring sleeves 51 and on the outer wall of the inner tube 5. An H-shaped connector 81 is slidably fitted on the slide rod 8. The connector 81 is hinged to one end of the connector 7 on the two adjacent spring sleeves 51. When the straightening rod 4 expands radially outward, the spring rod 52 drives the connector 7. The movement, combined with the sliding effect of connector 2 81 on slide rod 8, allows for the synchronous radial movement of all centralizing rods 4, thereby maintaining the same adaptive adjustment effect of all centralizing mechanisms. This ensures that the casing is well positioned in the center of the centralizer. When the casing is horizontally placed into the well, the centralizer moves horizontally. At this time, the bottom centralizing rod 4 is forced to drive the connected spring rod 52 to radially retract to its initial state. Correspondingly, connector 1 7 and connector 2 81 drive all centralizing mechanisms to retract synchronously, creating a rigid support effect for the centralizing mechanism. At the same time, the centralizing mechanism can adaptively adjust according to the inner wall of the well diameter, keeping the casing still in the center of the centralizer.

[0035] A spring groove 43 with an arc-shaped structure is provided in the middle of any straightening rod 4. The two ends of the spring groove 43 are connected to the adjusting slide grooves 41 on both sides respectively. A second spring 44 is provided in the spring groove 43. The second spring 44 is used to generate equal pressure on the two adjusting sliders 42 on the same straightening rod 4, so as to drive the adjusting sliders 42 to move when the straightening rod 4 expands radially.

[0036] Each straightening rod 4 has an arc-shaped slot 45 inside, with the two ends of the slot 45 passing through the two ends of the straightening rod 4. Two rotating plates 21 in the same straightening mechanism are fixedly installed with elastic baffles 46. The two elastic baffles 46 are inserted into the corresponding slots 45. The elastic baffles 46 are used to prevent the straightening rod 4 from hitting the inner wall of the well, which would cause the casing to become blocked.

[0037] Each of the two rotating plates 21 on any straightening mechanism is fixedly equipped with an elastic rope 9 for resetting the rotating plate 21. The side of the two elastic ropes 9 away from the rotating plate 21 is fixedly installed on the outer wall of the corresponding outer tube 1. The installation directions of the two elastic ropes 9 are opposite. When the straightening rod 4 in the same straightening mechanism tilts and disengages from the protrusion after being rotated by the two rotating plates 2, the rotating plate 2 is reset through the elastic rope 9, thereby resetting the straightening mechanism.

[0038] The working principle and usage of this invention are explained in detail below: During use, the casing is aligned by the straightening rod 4 contacting the inner wall of the well. When the inner wall of the well deforms due to stress and caves towards the axis, the rotating ring 12 causes the entire straightening mechanism to rotate around the rotating ring 12, disengaging the straightening mechanism from the caved area. Simultaneously, the remaining straightening mechanisms maintain support for the casing, thus centering it. When a large protrusion occurs at a certain point on the inner wall of the well, the pressure exerted on any one of the straightening rods 4 is greater. The straightening rod 4 can be tilted, which in turn drives the bending plate 3 to rotate. In order to maintain the connection effect between the straightening rod 4 and the bending plate 3 through the adjusting groove 41, the bending plate 3 is rotated in opposite directions through the two rotating plates 2 in the same straightening mechanism, which drives the bending plate 3 and the straightening mechanism to tilt and rotate as a whole, making way for the protrusion on the inner wall, which facilitates the lowering of the sleeve. When the straightening rod 4 in the same straightening mechanism tilts and disengages from the protrusion through the rotation of the two rotating plates 2, the elastic rope 9 drives the rotating plate 2 to reset, which in turn drives the straightening mechanism to reset. like Figure 4 As shown, in the initial state, the centralizing mechanism is in the narrowest diameter state of the well. When the centralizer moves to the wide diameter, the spring rod 52 moves radially outward through the spring 53. Under the action of the spring 44, the two adjusting sliders 42 move together. Furthermore, the adjusting sliders 42 pull the corresponding bending plate 3 to move, so that the centralizing mechanism can keep the casing in the middle of the centralizer according to the change of the inner diameter of the well. At the same time, when the casing enters the well horizontally, the cooperation of the connector 7 and the connector 81 makes the centralizing mechanism generate a rigid support effect, and at the same time, the centralizing mechanism can adaptively adjust according to the inner wall of the well diameter to keep the casing in the middle of the centralizer.

[0039] To further clarify, the aforementioned fixed connection should be interpreted broadly unless otherwise explicitly specified and limited. For example, it may be welding, gluing, or integral molding, or other conventional methods well known to those skilled in the art.

[0040] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An adaptive casing centralizer for drilling, comprising an outer casing (1) and a centralizing mechanism, characterized in that: Two outer tubes (1) are provided. Rotary grooves (11) are provided on the outer ring walls of the two outer tubes (1). Rotary rings (12) are rotatably connected in the two rotating grooves (11). The rotating rings (12) in the two rotating grooves (11) extend out of the rotating grooves (11). Several straightening mechanisms are provided. Several straightening mechanisms are provided between the two rotating rings (12). The aforementioned straightening mechanisms are distributed at equal angles. The straightening mechanism includes a rotating plate one (2), a rotating plate two (21), a bending plate (3), and a straightening rod (4) with an arc structure. Several protrusions (13) are provided on the outer wall of the outer tube (1). The protrusions (13) and the outer tube (1) are integrally formed. A groove (14) is provided on one side of the protrusion (13). The end of the groove (14) passes through the surface of the protrusion (13) away from the axis of the outer tube (1). The rotating plate one (2) is hinged in the groove (14). The rotating plate two (21) is hinged on the side of the rotating plate one (2) away from the groove (14). The bending plate (3) is hinged on the rotating plate two (21). An adjusting groove (41) is provided on the inner side wall of the straightening rod (4). An adjusting slider (42) is slidably connected in the adjusting groove (41).

2. The adaptive casing centralizer for drilling according to claim 1, characterized in that: The two grooves (14) in the same straightening mechanism are opened in opposite directions. There are two adjusting slides (41) of the straightening rod (4) in the same straightening mechanism. There are two bending plates (3) in the same straightening mechanism. The two bending plates (3) are installed in opposite directions. The bending plates (3) correspond one-to-one with the adjusting slides (41). One end of each of the two bending plates (3) is slidably connected to the adjusting slides (41) through the adjusting slider (42).

3. The adaptive casing centralizer for drilling according to claim 1, characterized in that: An inner tube (5) is provided between the two outer tubes (1), and several connecting pieces (6) are provided between any outer tube (1) and the inner tube (5) at equal angles. The two ends of any connecting piece (6) are respectively welded to the outer wall of the outer tube (1) and the inner tube (5).

4. The adaptive casing centralizer for drilling according to claim 3, characterized in that: Several spring sleeves (51) are fixedly installed on the outer wall of the inner tube (5). A spring rod (52) is inserted into the spring sleeve (51). The spring rod (52) corresponds to the straightening rod (4) one by one. The end of the spring rod (52) away from the spring sleeve (51) extends out of the spring sleeve (51) and is hinged to the inner side wall of the straightening rod (4). A spring (53) is provided inside the spring sleeve (51).

5. The adaptive casing centralizer for drilling according to claim 4, characterized in that: Two symmetrical through slots (54) are provided on the outer wall of any of the spring sleeves (51). A ring-shaped slot (55) is provided on the spring rod (52) inside any of the spring sleeves (51). A connector (7) is provided on the slot (55). Both ends of the connector (7) extend out of the through slot (54) and a synchronous sleeve (71) is slidably provided. A slide rod (8) is fixedly installed between any two spring sleeves (51) and on the outer wall of the inner tube (5). A connector (81) with an H-shaped structure is slidably provided on the slide rod (8). The connector (81) is hinged to one end of the connector (7) on the two adjacent spring sleeves (51).

6. The adaptive casing centralizer for drilling according to claim 1, characterized in that: The center of any of the straightening rods (4) is provided with an arc-shaped spring groove (43), and the two ends of the spring groove (43) are connected to the adjustment slides (41) on both sides respectively. A second spring (44) is provided in the spring groove (43).

7. The adaptive casing centralizer for drilling according to claim 1, characterized in that: Each of the straightening rods (4) has an arc-shaped slot (45) inside, and the two ends of the slot (45) pass through the two ends of the straightening rod (4). Two rotating plates (21) in the same straightening mechanism are fixedly installed with elastic baffles (46), and the two elastic baffles (46) are inserted into the corresponding slots (45).

8. The adaptive casing centralizer for drilling according to claim 1, characterized in that: Each of the two rotating plates (21) on the straightening mechanism is fixedly equipped with elastic ropes (9) for resetting the rotating plate (21). The side of the two elastic ropes (9) away from the rotating plate (21) is fixedly installed on the outer wall of the corresponding outer tube (1), and the installation directions of the two elastic ropes (9) are opposite.

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