Reducing centralizer

Abstract

The invention provides a variable-diameter centralizer, which relates to the technical field of centralizers and comprises a shell, a driving part and a connector part which are connected in sequence, the end, away from the driving part, of the shell is provided with a first connecting part. The end, away from the driving part, of the connector part is provided with a second connecting part. A first through hole is formed in the shell, a sliding groove communicating with the first through hole is formed in the outer wall of the shell, and an outer pushing block is arranged in the sliding groove in a sliding mode; the end, away from the connector part, of the driving part is slidably arranged in the first through hole in a penetrating mode and can transmit torque with the shell, the driving part makes contact with the outer pushing block through the conical surface, and the driving part can drive the outer pushing block to move towards the outside of the shell along with the movement of the driving part towards the first connecting part; the problems that in the prior art, a centralizer with the variable outer diameter cannot achieve stepless change of the outer diameter, the structure and the control mode are complex, and the diameter changing state cannot be visually displayed on the ground are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of centralizers, and more specifically, relates to a variable diameter centralizer. Background Art

[0002] The centralizers used in existing vertical wells and directional sections are all of fixed outer diameter. Before entering the well, a centralizer of corresponding diameter is placed in the drill bit assembly based on regional drilling experience, and the corresponding wellbore quality control method is used to detect the well inclination and azimuth. When there is a risk of exceeding the well inclination or the drilled section needs to be stabilized or corrected, it is necessary to reassemble the corresponding drill bit assembly after drilling and match the centralizer size to achieve the desired purpose. If a variable diameter centralizer is used, the number of drilling operations can be greatly reduced, saving drilling costs.

[0003] To this end, there are two types of centralizers with variable outer diameters in the prior art. One type requires that a push-tube mechanism be inserted into the drill bit after the drill bit is in place, and the outer diameter of the centralizer is enlarged under the action of hydraulic pressure. The outer diameter of the centralizer is small during the drilling process to prevent the risk of the drill bit being blocked during the drilling process. This type of centralizer with variable outer diameter can only achieve one diameter change, and the outer diameter size is single. Another type of centralizer with variable outer diameter can change the piston cavity pressure by driving the piston to move through a motor, push the push block to move outward, and can achieve two-level diameter change, but the structure is complex, and the diameter change gear cannot be intuitively displayed on the ground during the downhole diameter change process, which is easy to cause misjudgment.

[0004] Therefore, how to achieve the change of the outer diameter of the centralizer, and how to make the change of the outer diameter of the centralizer infinitely variable and easy to control and intuitively displayed on the ground, has become a technical problem that needs to be solved urgently. Summary of the invention

[0005] The purpose of the present invention is to provide a variable diameter centralizer to address the deficiencies in the prior art, thereby solving the problems that the centralizer with variable outer diameter in the prior art cannot achieve stepless change of outer diameter, has a complex structure and control method, and the variable diameter state cannot be intuitively displayed on the ground.

[0006] In order to achieve the above object, the present invention provides a variable diameter centralizer, comprising:

[0007] A housing, a driving part and a joint part connected in sequence;

[0008] A first connection portion is provided at one end of the housing away from the driving portion, and a second connection portion is provided at one end of the joint portion away from the driving portion;

[0009] A first through hole is provided inside the shell, a slide groove communicating with the first through hole is provided on the outer wall of the shell, and an outward push block is slidably provided in the slide groove;

[0010] One end of the driving part away from the joint part slides through the first through hole and can transmit torque to the outer shell. The driving part contacts the push-out block through a conical surface. As the driving part moves toward the first connecting part, the driving part can drive the push-out block to move outside the outer shell.

[0011] Optionally, a second through hole is provided inside the driving portion, and the second through hole is communicated with the first connecting portion and the second connecting portion.

[0012] Optionally, the joint portion is connected to an external thread on the driving portion through a threaded hole.

[0013] Optionally, a first step portion is provided on the inner periphery of the slide groove, a second step portion is provided on the outer periphery of the push block, a first elastic component is provided between the first step portion and the second step portion, and the first elastic component applies a first elastic force to the push block to move toward the inside of the shell.

[0014] Optionally, a third step portion is provided on the inner periphery of the first through hole, a fourth step portion is provided on the outer periphery of the driving portion, and a second elastic component is provided between the third step portion and the fourth step portion.

[0015] Optionally, the driving portion is cylindrical, and at least a portion of the outer circumference of the driving portion is a regular hexagon to form a transmission portion, and the inner circumference shape of the first through hole matches the outer circumference shape of the driving portion.

[0016] Optionally, four of the slide grooves and four of the extrapolation blocks are provided respectively, and each of the extrapolation blocks is slidably disposed in one of the slide grooves.

[0017] Optionally, the four slide grooves are evenly distributed on the outer wall of the shell along a circumference.

[0018] Optionally, an end face of the push-out block close to the outer end of the slide groove is in the shape of a long waist, an end face of the push-out block close to the inner end of the slide groove is provided with a first conical surface, and an end face of the driving part close to the first connecting part is provided with a second conical surface, and the second conical surface is in sliding contact with the first conical surface.

[0019] Optionally, an extension portion is provided on an end surface of the driving portion close to the first conical surface, and the extension portion is cylindrical and extends in a direction close to the first connecting portion.

[0020] The present invention provides a variable diameter centralizer, which has the following beneficial effects: the variable diameter centralizer comprises a first connection part and a second connection part, the first connection part is used to be connected to a drill pipe, and the second connection part is used to be connected to a drill collar, a drill bit or a drill pipe. During use, under the action of drilling pressure, a driving part can move in a direction close to the first connection part. Since the driving part contacts an outer push block through a conical surface, the outer push block can be pushed to move outside the outer push block shell, so that the outer push block extends to the outside of the shell, thereby achieving the diameter changing effect of the variable diameter centralizer. Moreover, this driving form of the conical surface contact can achieve stepless diameter changing. The control mode of drilling pressure control is convenient for displaying and controlling the outer diameter size after diameter changing on the ground. The variable diameter centralizer is not only easy to use, but also has a simple structure, low cost and is easy to produce.

[0021] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.

[0023] Figure 1 A schematic diagram of the appearance structure of a variable diameter centralizer according to an embodiment of the present invention is shown.

[0024] Figure 2 A schematic cross-sectional structure diagram of a variable diameter centralizer according to an embodiment of the present invention is shown.

[0025] Figure 3 A schematic structural diagram of a variable diameter centralizer according to an embodiment of the present invention is shown in a state where an outward push-out block is extended outward.

[0026] Figure 4 A schematic structural diagram of a driving portion of a variable diameter centralizer according to an embodiment of the present invention is shown.

[0027] Figure 5 A schematic structural diagram of an extrapolation block of a variable diameter centralizer according to an embodiment of the present invention is shown.

[0028] Description of reference numerals:

[0029] 1. Housing; 2. Driving part; 3. Joint part; 4. First connecting part; 5. Second connecting part; 6. Push-out block; 7. First elastic component; 8. Second elastic component; 9. Extension part; 10. External thread; 11. First conical surface; 12. Second conical surface; 13. Transmission part. DETAILED DESCRIPTION

[0030] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0031] like Figures 1 to 3 As shown, the present invention provides a variable diameter centralizer, comprising:

[0032] A housing 1, a driving part 2 and a joint part 3 connected in sequence;

[0033] A first connection portion 4 is disposed at one end of the housing 1 away from the driving portion 2, and a second connection portion 5 is disposed at one end of the joint portion 3 away from the driving portion 2;

[0034] A first through hole is provided inside the housing 1, and a slide groove communicating with the first through hole is provided on the outer wall of the housing 1, and an outward push block 6 is slidably provided in the slide groove;

[0035] One end of the driving part 2 away from the joint part 3 slides through the first through hole and can transmit torque to the outer shell 1. The driving part 2 contacts the push-out block 6 through the conical surface. As the driving part 2 moves toward the first connecting part 4, the driving part 2 can drive the push-out block 6 to move to the outside of the outer shell 1.

[0036] Specifically, in order to solve the problem that the centralizer with variable outer diameter in the prior art cannot achieve stepless change of outer diameter, and the structure and control method are complicated, and the diameter change state cannot be intuitively displayed on the ground; the variable diameter centralizer provided by the present invention has a first connecting part 4 and a second connecting part 5, the first connecting part 4 is used to connect with the drill pipe, and the second connecting part 5 is used to connect with the drill collar, drill bit or drill pipe. During use, under the action of drilling pressure, the driving part 2 can move in the direction close to the first connecting part 4. Since the driving part 2 contacts the push-out block 6 through the conical surface, it can push the push-out block 6 to move outside the outer shell 1, so that the push-out block 6 extends to the outside of the outer shell 1, thereby achieving the diameter change effect of the variable diameter centralizer, and this driving form of conical surface contact can achieve stepless diameter change, and the control method of drilling pressure control is convenient for displaying and controlling the outer diameter size after diameter change on the ground. The variable diameter centralizer is not only easy to use, but also simple in structure, low in cost and easy to produce.

[0037] Furthermore, during the use of the variable diameter centralizer, a variable diameter centralizer can be set near the drill bit. During the drilling process, the outer diameter of the variable diameter centralizer is controlled according to the drilling pressure, so that a better wellbore size can be obtained in the well section with easy diameter reduction or small well diameter expansion rate; the variable diameter centralizer can also be set in a drill tool assembly, for example, the drill tool assembly includes a drill bit, a centralizer, a bent screw, a drill collar, and a centralizer, and one or two of the centralizers are replaced with the variable diameter centralizer. In the process of drilling in a formation that is easy to deviate and a straight well section, a variable drill bit lateral force can be obtained through the variable diameter centralizer to achieve the effect of preventing deflection and drilling fast; the variable diameter centralizer can also be installed at the drill tool with large friction resistance in the open hole section during directional drilling, thereby reducing the friction resistance of the drill tool.

[0038] Optionally, a second through hole is provided inside the driving part 2 , and the second through hole is communicated with the first connecting part 4 and the second connecting part 5 .

[0039] Specifically, the first connecting part 4 and the second connecting part 5 are both standard drill bit buckles. The first connecting part 4 can be used to connect to the drill pipe, and the second connecting part 5 can be used to connect to the drill collar, drill bit or drill pipe; the second through hole in the driving part 2 forms a channel for the flow of drilling fluid during drilling.

[0040] Optionally, the joint part 3 is connected to the external thread 10 on the driving part 2 through a threaded hole.

[0041] Specifically, the upper end of the joint portion 3 is detachably connected to the external thread 10 on the driving portion 2 via a threaded hole, the threaded hole and the external thread 10 are both T-type threads, and the threaded hole is connected to the second connecting portion 5 .

[0042] Optionally, a first step portion is provided on the inner periphery of the slide groove, a second step portion is provided on the outer periphery of the push block 6, a first elastic component 7 is provided between the first step portion and the second step portion, and the first elastic component 7 applies a first elastic force to the push block 6 to move toward the inside of the shell 1.

[0043] Specifically, the setting of the first elastic component 7 can prevent the push-out block 6 from extending outward in a natural state, and the diameter of the variable diameter centralizer will not be changed. Only when the drilling pressure increases to overcome the first elastic force of the first elastic component 7, can the push-out block 6 be pushed outward to make it extend to the outside of the shell 1, thereby realizing the diameter change of the variable diameter centralizer. In addition, by setting the elastic coefficient of the first elastic component 7, the proportional relationship between the drilling pressure and the diameter change amount can be set as needed, so as to facilitate the control of the diameter change amount by the drilling pressure.

[0044] Optionally, a third step portion is provided on the inner periphery of the first through hole, a fourth step portion is provided on the outer periphery of the driving portion 2 , and a second elastic component 8 is provided between the third step portion and the fourth step portion.

[0045] Specifically, during the process of entering the well, the joint part 3 is subjected to the pulling force of the drill bit or drilling tool below it, and the driving part 2 moves downward to compress the second elastic component 8. At the same time, under the action of the first elastic component 7, the push block 6 remains in the slide groove on the outer shell 1 and does not extend to the outside of the outer shell 1.

[0046] Furthermore, the second elastic component 8 and the first elastic component 7 can also cooperate with the drilling pressure during actual drilling to adjust the upward movement distance of the driving part 2, thereby controlling the extension distance of the extrapolation block 6; specifically, the elastic force of the second elastic component 8 can be set according to the drilling pressure and the wellbore diameter expansion rate, and the actual drilling situation of the target block can be referred to. Before the tool leaves the factory, a relationship chart between the drilling pressure and the extension distance of the extrapolation block 6 is formulated, and the variable diameter size of the variable diameter straightener required for adjusting during the actual drilling process is guided during the field application; more importantly, the second elastic component 8 can also be pulled after the drilling pressure is applied. At this time, the second elastic component 8 can prevent the driving part 2 from moving excessively in the direction close to the outer shell 1 until it contacts the outer shell 1.

[0047] Optionally, the driving part 2 is cylindrical, and the outer circumference of at least part of the driving part 2 is a regular hexagon to form a transmission part 13 , and the inner circumference shape of the first through hole matches the outer circumference shape of the driving part 2 .

[0048] Specifically, Figure 4 As shown, at least part of the outer circumference of the cylindrical driving part 2 is a regular hexagon, and matches the inner circumference shape of the first through hole, so that after the driving part 2 is slidably inserted into the first through hole, torque can be transmitted between the driving part 2 and the housing 1.

[0049] Optionally, four slide grooves and four push-out blocks 6 are provided respectively, and each push-out block 6 is slidably disposed in a slide groove.

[0050] Specifically, in the initial state, the push-out block 6 is embedded in the slide groove and does not protrude outward. As the drilling pressure increases, the driving part 2 moves toward the first connecting part 4, and pushes the push-out block 6 outward through the conical surface, so that more and more push-out blocks 6 protrude outward from the outer shell 1, achieving diameter change.

[0051] Furthermore, when drilling to the bottom of the well or to the section where eye-marking is required, drilling pressure is applied, the joint part 3 pushes the driving part 2 to move upward, and the driving part 2 pushes the push-out block 6 to move along the slide groove to the outside of the shell 1 through the conical surface, thereby increasing the outer diameter of the variable diameter centralizer; according to the different drilling pressures applied, the outer diameter of the variable diameter centralizer is controlled based on the elastic force of the first elastic component 7; when lifting off the bottom of the well or reducing the drilling pressure, the driving part 2 moves downward, and under the action of the first elastic component 7, the push-out block 6 retracts, thereby reducing the outer diameter of the variable diameter centralizer.

[0052] In this embodiment, the first elastic component 7 and the second elastic component 8 are both springs.

[0053] Optionally, four slide grooves are evenly distributed on the outer wall of the housing 1 along a circumference.

[0054] Specifically, the four slide grooves are evenly distributed on the outer wall of the housing 1 along a circumference, so that the four push-out blocks 6 are evenly distributed on the same circumference, so that the force is evenly applied.

[0055] Optionally, one end face of the push-out block 6 close to the outer end of the slide groove is in the shape of a long waist, one end face of the push-out block 6 close to the inner end of the slide groove is provided with a first conical surface 11, and one end face of the driving part 2 close to the first connecting part 4 is provided with a second conical surface 12, and the second conical surface 12 is in sliding contact with the first conical surface 11.

[0056] Specifically, Figure 5 As shown, as the driving part 2 moves toward the first connecting part 4, the second conical surface 12 slides in contact with the first conical surface 11 and can push the first conical surface 11 and the push-out block 6 to move toward the outside of the housing 1 along the slide groove.

[0057] Optionally, an extension portion 9 is provided on the end surface of the driving portion 2 close to the first conical surface. The extension portion 9 is cylindrical and extends in a direction close to the first connecting portion 4 .

[0058] Specifically, the outer periphery of the extension portion 9 is used to contact the inner short end of the push-out block 6 close to the slide groove, playing a supporting and limiting role. In this embodiment, the first elastic component 7 is in a pre-compression state, and the push-out block 6 is limited by the extension portion 9.

[0059] In summary, the variable diameter stabilizer provided by the present invention can control its diameter change amount based on the drilling pressure, is suitable for replacing conventional stabilizers, and can realize infinite steps of diameter change of the outer diameter size of the stabilizer underground. When used in diameter and directional drilling, it can improve the wellbore quality and reduce the number of drilling operations.

[0060] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A variable diameter centralizer, characterized in that: include: A housing, a driving part and a joint part connected in sequence; A first connection portion is provided at one end of the housing away from the driving portion, and a second connection portion is provided at one end of the joint portion away from the driving portion; A first through hole is provided inside the shell, a slide groove communicating with the first through hole is provided on the outer wall of the shell, and an outward push block is slidably provided in the slide groove; One end of the driving part away from the joint part slides through the first through hole and can transmit torque to the outer shell. The driving part contacts the push-out block through a conical surface. As the driving part moves toward the first connecting part, the driving part can drive the push-out block to move outside the outer shell.

2. The variable diameter centralizer according to claim 1, characterized in that: A second through hole is disposed inside the driving portion, and the second through hole is communicated with the first connecting portion and the second connecting portion.

3. The variable diameter centralizer according to claim 1, characterized in that: The joint part is connected with the external thread on the driving part through a threaded hole.

4. The variable diameter centralizer according to claim 1, characterized in that: A first step portion is provided on the inner periphery of the slide groove, a second step portion is provided on the outer periphery of the push-out block, a first elastic component is provided between the first step portion and the second step portion, and the first elastic component applies a first elastic force to the push-out block to move toward the inside of the shell.

5. The variable diameter centralizer according to claim 1, characterized in that: A third step portion is disposed on the inner periphery of the first through hole, a fourth step portion is disposed on the outer periphery of the driving portion, and a second elastic component is disposed between the third step portion and the fourth step portion.

6. The variable diameter centralizer according to claim 1, characterized in that: The driving part is cylindrical, and at least a portion of the outer circumference of the driving part is a regular hexagon to form a transmission part. The inner circumference shape of the first through hole matches the outer circumference shape of the driving part.

7. The variable diameter centralizer according to claim 1, characterized in that: The number of the slide grooves and the number of the push-out blocks are four respectively, and each push-out block is slidably disposed in one of the slide grooves.

8. The variable diameter centralizer according to claim 7, characterized in that: The four slide grooves are evenly distributed on the outer wall of the shell along a circumference.

9. The variable diameter centralizer according to claim 1, characterized in that: One end face of the push-out block close to the outer end of the slide groove is in the shape of a long waist, one end face of the push-out block close to the inner end of the slide groove is provided with a first conical surface, and one end face of the driving part close to the first connecting part is provided with a second conical surface, and the second conical surface is in sliding contact with the first conical surface.

10. The variable diameter centralizer according to claim 9, characterized in that: An extension portion is provided on the end surface of the driving portion close to the first tapered surface. The extension portion is cylindrical and extends in a direction close to the first connecting portion.

Images