Dynamic pressure balance centralizing assembly applied to extended reach well operation

Abstract

The present invention discloses a dynamic pressure balance centralizing assembly applied to extended reach well operations, which relates to the technical field of drilling operations. A centralizing structure is optimized for the drilling process of extended reach wells. Essentially, it is still based on the structure of elastic support members, but the difference is that: during the specific operation process, the hydraulic pressure of the drilling fluid is fully utilized. Its essence is to drive the self-swinging hemispherical fan to perform adaptive rotation. The key lies in the fact that the self-swinging hemispherical fan performs adaptive position change along the drilling direction. Then, during the overall operation process, first, the pressure of the drilling fluid itself is utilized, and it is combined with the elastic support force of the calabash spring frame. In addition, the rotation action and position change action of the self-swinging hemispherical fan are used to drive the bidirectional swing rod therein to perform directional rotation, driving the pressure plate at the corresponding position to receive the extrusion of the pressure-receiving plate, and performing two actions of secondary support or reducing the rebound of the calabash spring frame, reducing the excessive pressure on the inner wall of the wellbore and avoiding directly damaging the inner wall of the wellbore.

Description

Technical Field

[0001] The present invention relates to the technical field of drilling operations, and particularly relates to a dynamic pressure balance centralizing assembly applied to extended reach well operations. Background Art

[0002] An extended reach well mainly refers to a well with a vertical-to-horizontal ratio of not less than 2 and a measured depth greater than 3000 m, or a well with a horizontal displacement greater than 3000 m. Its wellbore environment is relatively complex, which is particularly prominent in its drilling operations. A centralizing structure is added to conventional drill strings. Taking the relevant content in Publication Nos. CN106703695A and CN115506727A as examples.

[0003] It should be noted that: Conventional centralizing structures mainly utilize elastic support forces to reduce frictional resistance. However, due to the long and complex wellbore trajectory, the frictional resistance of the drill string in the wellbore increases significantly, resulting in an increase in torque and frictional resistance. Simple elastic structural members cannot fully adapt to the wellbore environment, and conventional centralizing structures may directly damage the structural stability of the wellbore inner wall, making the wellbore wall prone to instability, leading to wellbore collapse or diameter reduction.

[0004] For this, the present application proposes a solution. Summary of the Invention

[0005] The purpose of the present invention is to provide a dynamic pressure balance centralizing assembly applied to extended reach well operations. For extended reach drilling operations, because the wellbore environment of extended reach wells is complex, conventional centralizing structures mainly rely on the elastic support forces of elastic structural members and cannot fully adapt to the wellbore environment, and even affect the wellbore stability.

[0006] The purpose of the present invention can be achieved through the following technical solutions: A dynamic pressure balance centralizing assembly applied to extended reach well operations, which is applied in extended reach drilling operations, includes an outer sleeve and a gourd spring frame. The gourd spring frame is arranged outside the outer sleeve along the center point position of the outer sleeve, and one end of the gourd spring frame is hinged to the outer wall of the outer sleeve.

[0007] A self-swinging hemispherical fan is arranged inside the outer sleeve. A connecting support rod is installed at the lower end of the self-swinging hemispherical fan. A two-way swing rod is installed at the lower end of the connecting support rod. A pressure receiving plate is arranged inside the outer sleeve corresponding to the inside of the two-way swing rod. A connecting guide rod is installed at the center point of the outer wall of the pressure receiving plate away from the center point of the outer sleeve. A rubber piston block is installed on the connecting guide rod.

[0008] Further arranged as: The outer surface of the self-swinging hemispherical fan is a spherical surface, and the self-swinging hemispherical fan is movably connected along the center point of the spherical surface inside the outer sleeve. The center point of the two-way swing rod and the center point of the spherical surface in the self-swinging hemispherical fan are not on the same axis.

[0009] Further set as: the self - swinging hemispherical fan and the bidirectional swing rod are arranged in sequence along the drilling direction during the drilling operation.

[0010] Further set as: the calabash spring frame is in a double - wave shape along the drilling direction during the drilling operation and is respectively set as the first peak and the second peak, and the cross - section of the first peak and the second peak in the calabash spring frame is in a curved arch shape along the direction away from the center point of the outer sleeve.

[0011] Further set as: the length of the calabash spring frame is greater than the length of the outer sleeve, and the arc length of the first peak in the calabash spring frame is less than the arc length of the second peak.

[0012] Further set as: the installation position of the connecting guide rod corresponds to the intersection position of the first peak and the second peak, and pin caps are installed at both ends of the connecting guide rod corresponding to the outer wall and the inner wall of the calabash spring frame.

[0013] Further set as: a through - pipe is installed at the position of the outer sleeve corresponding to the connecting guide rod, the rubber piston block is slidably connected to the inner wall of the through - pipe, and a connecting spring is arranged at the middle position of the connecting guide rod corresponding to the rubber piston block and the pressure - receiving plate.

[0014] Further set as: the bidirectional swing rod is composed of two top - position rods, the included angle between the two top - position rods is greater than 90 degrees and less than 180 degrees, and the lengths of the two top - position rods are different.

[0015] Further set as: pressure plates are installed at the end positions of the two top - position rods, the pressure - receiving plates are arranged in an annular array along the center point of the outer sleeve, and the arc length of the pressure plate is greater than the arc length of the pressure - receiving plate.

[0016] The present invention has the following beneficial effects:

[0017] 1. The overall structure still achieves the purpose of straightening based on the elastic supporting force of the calabash spring frame. However, the difference is that during the release process of the drilling fluid, the hydraulic pressure drives the self - swinging hemispherical fan to rotate adaptively. In essence, it can drive the bidirectional swing rod to rotate directionally. The key lies in the optimization method of the calabash spring frame. The calabash spring frame has two elastic supporting processes, which essentially avoid applying excessive pressure on the inner wall of the wellbore by the calabash spring frame and damaging the structural stability of the inner wall of the wellbore.

[0018] 2. Based on the above content, the self - swinging hemispherical fan is further optimized. The self - swinging hemispherical fan can move freely under the action of the gravitational field, so as to cooperate with the drilling direction to make the self - swinging hemispherical fan freely change positions. Combined with the rotational movement generated by the hydraulic pressure of the drilling fluid, it drives the two - way swing rod to rotate freely. During the movement of the two - way swing rod, the two pressure plates on it perform rotational movements in irregular circular or elliptical ways, driving the pressure plates at the corresponding positions to be squeezed by the pressure - receiving plate. During the whole process, it can drive the connecting guide rod to move linearly along the direction pointing to the center of the outer sleeve, performing two actions of second - supporting the calabash spring frame or reducing the rebound, reducing the excessive pressure on the inner wall of the wellbore and avoiding directly damaging the inner wall of the wellbore. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0020] Figure 1 Structural schematic diagram of the dynamic pressure balance centralizer assembly applied to the operation of extended - reach wells proposed by the present invention;

[0021] Figure 2 In the dynamic pressure balance centralizer assembly applied to the operation of extended - reach wells proposed by the present invention Figure 1 Cross - sectional view;

[0022] Figure 3 In the dynamic pressure balance centralizer assembly applied to the operation of extended - reach wells proposed by the present invention Figure 1 Top view;

[0023] Figure 4 In the dynamic pressure balance centralizer assembly applied to the operation of extended - reach wells proposed by the present invention Figure 1 Sectional view;

[0024] Figure 5 Front view of the calabash spring frame corresponding to the outer sleeve in the dynamic pressure balance centralizer assembly applied to the operation of extended - reach wells proposed by the present invention;

[0025] Figure 6 Structural schematic diagram of the self - swinging hemispherical fan in the dynamic pressure balance centralizer assembly applied to the operation of extended - reach wells proposed by the present invention;

[0026] Figure 7 In the dynamic pressure balance centralizer assembly applied to the operation of extended - reach wells proposed by the present invention Figure 1 Bottom view corresponding to the two - way swing rod.

[0027] In the figure: 1. Outer sleeve; 2. Gourd spring frame; 3. Self - swinging hemispherical fan; 4. Connecting support rod; 5. Bi - directional swing rod; 6. Pressure - receiving plate; 7. Connecting guide rod; 8. Rubber piston block; 9. Connecting spring; 10. Pressure plate. Specific implementation mode

[0028] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0029] Embodiment 1: For large - displacement drilling operations, because the wellbore environment of large - displacement wells is complex, the conventional centralizing structure mainly relies on the elastic support force of elastic structural members and cannot fully adapt to the wellbore environment, and even affects the wellbore stability. Therefore, the following technical solutions are proposed:

[0030] Refer to Figures 1 - 7 , the dynamic pressure - balanced centralizing assembly applied to large - displacement well operations in this embodiment is applied in large - displacement drilling operations, including an outer sleeve 1 and a gourd spring frame 2. The gourd spring frame 2 is arranged outside the outer sleeve 1 along the center point position of the outer sleeve 1, and one end of the gourd spring frame 2 is hinged to the outer wall of the outer sleeve 1;

[0031] A self - swinging hemispherical fan 3 is arranged inside the outer sleeve 1. A connecting support rod 4 is installed at the lower end of the self - swinging hemispherical fan 3. A bi - directional swing rod 5 is installed at the lower end of the connecting support rod 4. A pressure - receiving plate 6 is arranged inside the outer sleeve 1 corresponding to the position of the bi - directional swing rod 5. A connecting guide rod 7 is installed at the center point of the outer wall of the pressure - receiving plate 6 away from the center point of the outer sleeve 1. A rubber piston block 8 is installed on the connecting guide rod 7. The outer surface of the self - swinging hemispherical fan 3 is a spherical surface, and the self - swinging hemispherical fan 3 is movably connected along the center point of the spherical surface inside the outer sleeve 1. The center point of the bi - directional swing rod 5 and the center point of the spherical surface in the self - swinging hemispherical fan 3 are not on the same axis. The self - swinging hemispherical fan 3 and the bi - directional swing rod 5 are arranged in sequence along the drilling direction during the drilling operation.

[0032] Working principle: First of all, it should be noted that: The present invention mainly aims at the centralizing structure used in the process of large - displacement drilling operations. Because drilling fluid needs to be continuously output during drilling operations, on the one hand, the centralizing structure is to maintain the drilling direction, and on the other hand, it cannot directly interfere with the drilling operation process. Taking Figure 1 as an example, the outer sleeve 1 in the overall structure is installed at the rear position of the drill string. Thus, it can be understood that: The output drilling fluid will first pass through the outer sleeve 1, specifically through the self - swinging hemispherical fan 3 inside it. Taking Figure 4 and Figure 6For example, since the essence of the self - oscillating hemispherical fan 3 is a turbine blade, and a spherical outer casing is installed at its outer position to form the self - oscillating hemispherical fan 3, it is driven by the hydraulic pressure of the drilling fluid itself to rotate adaptively;

[0033] And when the overall structure continuously enters the wellbore, specifically, the elastic support force of the calabash spring frame 2 is used to straighten and guide the overall outer casing 1. For this, it is necessary to ensure that one end of the calabash spring frame 2 is as close as possible to the outer casing 1 to avoid directly interfering with the movement process of the overall structure.

[0034] Embodiment 2: Explain the movement process of the two - way swing rod cooperating with the self - oscillating hemispherical fan:

[0035] The calabash spring frame 2 is in a double - wave shape along the drilling direction during the drilling operation and is respectively set as the first peak and the second peak. And the cross - section of the first peak and the second peak in the calabash spring frame 2 is in a curved arch shape along the direction away from the center point of the outer casing 1. The length of the calabash spring frame 2 is greater than the length of the outer casing 1, and the arc length of the first peak in the calabash spring frame 2 is less than the arc length of the second peak. The connecting guide rod 7 is set at the intersection position of the first peak and the second peak. And pin caps are installed at both ends of the connecting guide rod 7 corresponding to the outer wall and the inner wall of the calabash spring frame 2. A through - tube is installed on the outer casing 1 corresponding to the position of the connecting guide rod 7. The rubber piston block 8 is slidably connected to the inner wall of the through - tube. A connecting spring 9 is arranged at the middle position of the connecting guide rod 7 corresponding to the rubber piston block 8 and the pressure - receiving plate 6.

[0036] Scheme description: As shown in Embodiment 1, and taking Figure 2 as an example, when the overall structure continuously penetrates into the wellbore at the position shown in Figure 2 , because the outer casing 1 is in a completely vertical state in this state, under the action of the gravitational field, the overall two - way swing rod 5 can be set as the gravity component corresponding to the self - oscillating hemispherical fan 3. Thus, it can be understood that the connecting support rod 4 remains vertical. However, because of the large - displacement well operation mentioned in the present invention, since the wellbore environment is not completely vertical, the outer casing 1 proposed by the present invention is inclined in an indefinite direction under the influence of the wellbore environment. Therefore, under the action of the gravitational field, the connecting support rod 4 will undergo an indefinite - direction inclination process. This part is the key process of the present invention.

[0037] Embodiment 3: Supplementary description of Embodiment 2, specifically reflected in the calabash spring frame therein:

[0038] The two - way swing rod 5 is composed of two top - position rods. The included angle between the two top - position rods is greater than 90 degrees and less than 180 degrees, and the lengths of the two top - position rods are different. Pressure plates 10 are installed at the end positions of the two top - position rods. The pressure - receiving plate 6 is arranged in an annular array along the center point of the outer casing 1. The arc length of the pressure plate 10 is greater than the arc length of the pressure - receiving plate 6.

[0039] Set up the following process by combining Embodiment 1 and Embodiment 2:

[0040] S1: First, refer to Figure 7 , this part is based on the state where the overall outer sleeve 1 remains completely horizontal, and also because the center point of the bidirectional swing rod 5 and the center point of the spherical surface in the self-swinging hemispherical fan 3 are not on the same axis. Therefore, although the bidirectional swing rod 5 is connected to the self-swinging hemispherical fan 3 through the connecting support rod 4, in order to satisfy the "gravity effect" of the gravitational field, the connection point between the connecting support rod 4 and the bidirectional swing rod 5 is not located at the center point position of the bidirectional swing rod 5;

[0041] In this theoretical state, there is always a pressure plate 10 on one of the top rods in contact with the pressure-receiving plate 6, while there is an obvious gap between the pressure plate 10 on the other top rod and the pressure-receiving plate 6. Therefore, when the self-swinging hemispherical fan 3 rotates in its initial state, the trajectories followed by the pressure plates 10 on the two top rods are not complete circles, but elliptical trajectories of this kind. Only one of the pressure plates 10 exerts pressure on the pressure-receiving plate 6 and does not exert excessive pressure on the pressure-receiving plate 6. If one of the calabash spring frames 2 comes into contact with the inner wall of the shaft and deforms, it will also provide a reverse pressure to the pressure-receiving plate 6 through the connecting guide rod 7, but as Figure 7 shown, each pressure plate 6 is arranged in a circular array along the center point of the outer sleeve 1 and forms a complete circle. Therefore, the pressure generated during the deformation process of the calabash spring frame 2 can be directly ignored, specifically the deformation process of the calabash spring frame 2;

[0042] S2: Based on S1 and referring to Figure 5 , the calabash spring frame 2 first deforms when its second peak comes into contact with the inner wall of the shaft. Due to the second peak first coming into contact with the inner wall of the shaft and being squeezed and deformed, and because there is a through hole corresponding to the connecting guide rod 7 at the intersection of the first peak and the second peak, the diameter of the through hole is larger than the outer diameter of the connecting guide rod 7 and smaller than the outer diameter of the pin cap. Therefore, the first peak will undergo a deformation process again during the deformation process of the second peak, resulting in an increase in the bending arc of the first peak. Thus, the support process for the inner wall of the shaft is completed jointly by the first peak and the second peak;

[0043] S3: Combining S1 and S2 again, because the shaft of the large-displacement well is not completely vertical, the self-swinging hemispherical fan 3 undergoes an indeterminate self-swing, which drives the bidirectional swing rod 5 to change positions, possibly causing one of the pressure plates 10 to provide a large pressure to the pressure-receiving plate 6, driving the connecting guide rod 7 to move linearly in a direction away from the center point of the outer sleeve 1. This process also includes the following content:

[0044] S3-1: Take Figure 2For example, if the overall outer sleeve 1 deflects slightly in the counterclockwise direction, the pressure plate 10 in the bidirectional swing rod 5 will be closer to the pressure-receiving plate 6. However, the bidirectional swing rod 5 will still continue to rotate through the self-swinging hemispherical fan 3. Refer to Figure 5 for illustration. Due to the pressure acting on the pressure-receiving plate 6, the connecting guide rod 7 is driven to linearly move away from the center point of the outer sleeve 1. And because the calabash spring frame 2 is only hinged at one end and thus has mobility, the calabash spring frame 2 is driven by the active movement of the connecting guide rod 7 to further contact the inner wall of the wellbore;

[0045] S3-2: Taking S3-1 as an example, when the outer sleeve 1 deflects slightly, it causes the overall outer sleeve 1 to more "easily" contact the inner wall of the wellbore relative to the calabash spring frame 2 on the left side. Therefore, it is necessary to further limit the length dimension of the top-position rod on the bidirectional swing rod 5. Specifically, when the pressure plate 10 further presses the pressure-receiving plate 6 and further applies pressure to the inner wall of the wellbore, in this state, the overall outer sleeve 1 will undergo a "lateral movement" process, and the overall "lateral movement" direction is opposite to the linear movement direction of the connecting guide rod 7, so as to further maintain the centered position of the overall outer sleeve 1;

[0046] S3-3: Taking Figure 5 as an example again, the pressure-receiving plate 6 deflects counterclockwise under the pressure of the pressure plate 10, providing pressure to the calabash spring frame 2 to cause the calabash spring frame 2 to undergo a secondary deformation process. However, it needs to be further explained in combination with the drilling fluid: Because the drilling fluid used in the drilling process has a relatively high hydraulic pressure, it will provide pressure to the rubber piston block 8 in the direction away from the center point of the outer sleeve 1. But during the drilling process, mud will continuously be generated, and the mud will provide pressure to the rubber piston block 8 in the direction pointing to the center point of the outer sleeve 1. Thus, the overall structure combines the hydraulic pressure of the drilling fluid, the mud pressure, and the pressure generated when contacting the inner wall of the wellbore. Through the synergistic action of the three, it can better adapt to the wellbore environment and avoid problems such as damaging the structural stability of the inner wall of the wellbore, easy instability of the wellbore wall, collapse or shrinkage of the wellbore wall.

[0047] In summary: The centralizing structure optimized for the drilling process of the extended-reach well is still essentially based on the structure of the elastic support member. However, the difference is that during the specific operation process, the hydraulic pressure of the drilling fluid is fully utilized. Its essence is to drive the self-swinging hemispherical fan 3 to perform adaptive rotation. The key lies in the adaptive position change of the self-swinging hemispherical fan 3 along with the drilling direction. Then, during the overall operation process, first, the pressure of the drilling fluid itself is utilized, and the elastic support force of the calabash spring frame 2 is combined. In addition, the rotation action and position change action of the self-swinging hemispherical fan 3 are used to drive the bidirectional swing rod 5 therein to perform directional rotation, driving the pressure plate 10 at the corresponding position to be squeezed by the pressure-receiving plate 6, performing two actions of secondary support or reducing the rebound of the calabash spring frame 2, reducing the excessive pressure on the inner wall of the wellbore, and avoiding directly damaging the inner wall of the wellbore.

[0048] The above content is only an example and illustration of the structure of the present invention. Those skilled in the art of this technology can make various modifications, supplements, or use similar methods to replace the described specific embodiments, as long as they do not deviate from the structure of the invention or exceed the scope defined by this claim book, they should all fall within the protection scope of the present invention.

[0049] In the description of this specification, the description referring to terms such as "one embodiment", "example", "specific example", 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 expressions 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.

[0050] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only the specific implementation manners. Obviously, according to the content of this specification, many modifications and changes can be made. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is only limited by the claim book and its full scope and equivalents.

Claims

1. A dynamic pressure balance centralizing assembly applied to large-displacement well operations, characterized in that, Applied in large-displacement drilling operations, it includes an outer casing (1) and a calabash spring frame (2). The calabash spring frame (2) is arranged outside the outer casing (1) along the center point position of the outer casing (1), and one end of the calabash spring frame (2) is hinged to the outer wall of the outer casing (1). A self-swinging hemispherical fan (3) is arranged inside the outer casing (1). A connecting support rod (4) is installed at the lower end of the self-swinging hemispherical fan (3). A two-way swing rod (5) is installed at the lower end of the connecting support rod (4). A pressure receiving plate (6) is arranged inside the outer casing (1) corresponding to the inside of the two-way swing rod (5). A connecting guide rod (7) is installed at the center point of the outer wall of the pressure receiving plate (6) away from the center point of the outer casing (1). A rubber piston block (8) is installed on the connecting guide rod (7). The outer surface of the self-swinging hemispherical fan (3) is spherical, and the self-swinging hemispherical fan (3) is movably connected inside the outer casing (1) along the center point of the spherical surface. The center point of the two-way swing rod (5) and the center point of the spherical surface in the self-swinging hemispherical fan (3) are not on the same axis. The calabash spring frame (2) is in a double-wave shape along the drilling direction in the drilling operation and is respectively set as the first peak and the second peak. The cross-section of the first peak and the second peak in the calabash spring frame (2) is in a curved arch shape along the direction away from the center point of the outer casing (1). The connecting guide rod (7) is arranged at the intersection position of the first peak and the second peak, and pin caps are installed at both ends of the connecting guide rod (7) corresponding to the outer wall and the inner wall of the calabash spring frame (2). A through hole corresponding to the connecting guide rod (7) is opened at the intersection position of the first peak and the second peak. The diameter of the through hole is larger than the outer diameter of the connecting guide rod (7) and smaller than the outer diameter of the pin cap.

2. The dynamic pressure balance centralizing assembly applied to the operation of extended reach wells according to claim 1, wherein The self-swinging hemispherical fan (3) and the two-way swing rod (5) are arranged in sequence along the drilling direction in the drilling operation.

3. The dynamic pressure balance centralizing assembly applied to the operation of extended reach wells according to claim 1, wherein The length of the calabash spring frame (2) is greater than the length of the outer casing (1), and the arc length of the first peak in the calabash spring frame (2) is less than the arc length of the second peak.

4. The dynamic pressure balance centralizing assembly applied to the operation of extended reach wells according to claim 1, wherein A through pipe is installed at the position of the outer casing (1) corresponding to the connecting guide rod (7). The rubber piston block (8) is slidably connected to the inner wall of the through pipe. A connecting spring (9) is arranged at the middle position of the connecting guide rod (7) corresponding to the rubber piston block (8) and the pressure receiving plate (6).

5. The dynamic pressure balance centralizing assembly applied to the operation of extended reach wells according to claim 1, wherein The two-way swing rod (5) is composed of two top-position rods. The included angle between the two top-position rods is greater than 90 degrees and less than 180 degrees, and the lengths of the two top-position rods are different.

6. The dynamic pressure balance centralizing assembly applied to the operation of extended reach wells according to claim 5, characterized in that, Pressure plates (10) are installed at the end positions of the two top-position rods. The pressure receiving plates (6) are arranged in an annular array along the center point of the outer casing (1). The arc length of the pressure plate (10) is greater than the arc length of the pressure receiving plate (6).

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