Novel centralizer structure

Abstract

The utility model relates to the technical field of oil exploitation, in particular to a novel centralizer structure, which comprises a mandrel, a centralizer body, a centralizer core and a centralizer core, the roller arm fixing sleeve is sleeved on the mandrel, and one end of the roller arm fixing sleeve is provided with a plurality of long grooves and short grooves which are distributed in a staggered manner; the spring is arranged on the core shaft in a sleeving manner and is positioned between the roller arm fixing sleeve and the core shaft; the pressing screw sleeve is arranged at the end part of the roller arm fixing sleeve; the adjusting screw sleeve is sleeved between the mandrel and the pressing screw sleeve, and the position of the adjusting screw sleeve can be adjusted in the axial direction of the mandrel; the upper roller arm and the lower roller arm are respectively hinged in the long groove and the short groove, and the upper roller arm and the lower roller arm are movably connected through a pin shaft; the pin shaft is sleeved with a roller; the elastic sheet is fixed on the upper roller arm; the baffle rings sleeve the mandrel and are positioned at two ends of the spring, and a plurality of studs are fixed on the surfaces of the baffle rings; a protrusion is arranged at the end, connected with the roller arm fixing sleeve, of the upper roller arm. Through the synergistic effect of the spring and the elastic piece, segmented supporting under the working conditions of a large well hole and a small well hole can be achieved.

Description

Technical Field

[0001] This utility model relates to the field of oil extraction technology, and in particular to a novel centralizer structure. Background Technology

[0002] With the development of oil logging technology, logging depths are increasing, formations are becoming more complex, and well temperatures are rising. Conventional instruments designed for 150°C or 175°C are no longer suitable for long-term operation in harsh logging environments with temperatures exceeding 200°C and strong vibrations. This is mainly because the original boom opening and closing controls relied on touch limit switches to disconnect and connect the circuit.

[0003] As the depth of the instrument descends into the well, the underground temperature increases. The operating temperature of the instrument also rises accordingly. Since limit switches may not function properly in environments of 200℃-230℃, a structure is needed to replace the limit switches and ensure proper arm opening and closing. Logging instruments require the acquisition of well diameter dimensions or for sensors to be in close contact with the well wall, necessitating the extension of the robotic arm for measurement or to provide support. The instrument needs a relatively flat surface for easy descent. During measurement, the arm is extended, and sometimes repeated measurements at a specific depth are required, necessitating repeated arm opening and closing. If the arm cannot open and close properly, repeated measurements are impossible. In severe cases, the extended structure may embed into the well wall, resulting in excessive lifting force and preventing the instrument from being pulled out from underground, leading to a logging accident.

[0004] The original transmission structure required adjusting the distance of the limit switch to open and close the robotic arm. The limit switch contacts often deformed, causing the switch to malfunction. The transmission mechanism continued to operate beyond its limit position, thus damaging the motor and transmission components. Utility Model Content

[0005] To address the problems mentioned in the background art, this utility model provides a novel centralizer structure that achieves segmented support under both large and small wellbore conditions through the synergistic action of springs and spring plates. In large wellbore conditions, the springs primarily provide high support force; in small wellbore conditions, the spring plates supplement the support through the elastic deformation of the arc-shaped metal sheet, ensuring stable centralizing force throughout the entire well section regardless of wellbore size changes. This solves the problem of wellbore adhesion failure caused by insufficient support force from a single spring in traditional structures.

[0006] The technical solution adopted by this utility model to solve its technical problem is as follows: a novel centralizer structure is provided, comprising: a spindle with a boss in the middle of its outer side; a roller arm fixing sleeve, sleeved on the spindle, one end of which has several staggered long and short grooves; a spring, sleeved on the spindle and located between the roller arm fixing sleeve and the spindle; a clamping screw sleeve, located at the end of the roller arm fixing sleeve; and an adjusting screw sleeve, sleeved between the spindle and the clamping screw sleeve, the position of which can be adjusted along the axial direction of the spindle. Adjustment; the upper roller arm and the lower roller arm are respectively hinged in the long groove and the short groove, and the upper roller arm and the lower roller arm are movably connected by a pin; a roller is sleeved on the pin; a spring is fixed on the upper roller arm; a retaining ring is sleeved on the spindle and located at both ends of the spring, and several studs are fixed on its surface; a protrusion is provided at the end of the upper roller arm that connects to the roller arm fixing sleeve, and the protrusion abuts against the studs of the retaining ring; a through hole is opened at the bottom of the long groove; the boss is used to axially limit the roller arm fixing sleeve.

[0007] The design of the mandrel and roller arm fixing sleeve, combined with the segmented support mechanism of spring and spring sheet, can ensure that the centralizer can work stably in both large and small wells, solving the problem of well wall adhesion failure caused by insufficient support force of a single spring in traditional structures.

[0008] Furthermore, the long and short grooves of the roller arm fixing sleeve are evenly distributed circumferentially in an alternating pattern. This staggered distribution ensures symmetrical roller arm deployment angles, preventing localized stress concentrations, improving the uniformity of support force distribution, and reducing the risk of uneven wear during contact with the well wall. The evenly distributed long and short groove design ensures the robotic arm maintains dynamic balance under complex well conditions, preventing jamming or wear of transmission components due to uneven force distribution.

[0009] Furthermore, the adjusting sleeve and the clamping sleeve are connected by threads, allowing adjustment of their axial position to change the spring compression. Rotating the adjusting sleeve directly changes the spring compression, achieving linear adjustment of the support force. This method is simple to operate and responds quickly, adapting to the dynamic needs of different well diameters and downhole pressures. The threaded connection design eliminates the need for additional tools, significantly improving field operation efficiency, and is particularly suitable for high-temperature, confined downhole environments.

[0010] Furthermore, the number of studs on the retaining ring matches the number of long slots, with each stud corresponding to a protrusion within a slot. Each stud corresponds one-to-one with a protrusion on the roller arm, limiting the maximum extension angle of the roller arm and preventing motor overload or damage to transmission components caused by overtravel of the robotic arm. The synergistic effect of multiple studs enhances the reliability of the limit; even if a single stud fails, the remaining studs can still provide protection, reducing the risk of logging accidents.

[0011] Furthermore, the spring is an arc-shaped metal sheet, fixed to the upper roller arm, used to provide restoring elasticity. The geometric design of the arc-shaped spring can evenly distribute stress and maintain high elasticity after multiple compressions, avoiding the decrease in support force caused by fatigue in traditional springs. The spring deforms under small wellbore conditions, providing additional radial support force to compensate for insufficient spring force and ensure stable wellbore adhesion.

[0012] Furthermore, the diameter of the through-hole is larger than that of the stud, allowing the stud to move axially within the through-hole. The clearance design between the through-hole and the stud absorbs dimensional deviations caused by temperature changes or manufacturing tolerances, preventing jamming of the robotic arm due to thermal expansion and contraction or assembly errors. Allowing the stud to make axial fine adjustments within the through-hole ensures smooth compression of the roller arm during vertical movement, reducing the risk of sudden changes in logging pull.

[0013] Furthermore, the outer surface of the roller is coated with a wear-resistant coating, and its axis is perpendicular to the mandrel axis. The wear-resistant coating can significantly reduce the wear rate when the roller rubs against the well wall, extend the roller's service life, and reduce the frequency of downhole replacement. The design of the roller axis being perpendicular to the mandrel ensures that it is a pure rolling friction when in contact with the well wall, reducing energy loss and heat accumulation caused by sliding friction and improving logging efficiency.

[0014] Compared with the prior art, the beneficial effects of this utility model are:

[0015] 1. This invention achieves segmented support for both large and small wellbore conditions through the synergistic action of springs and spring plates. In large wellbore conditions, the springs primarily provide high support force; in small wellbore conditions, the spring plates supplement the support through the elastic deformation of the arc-shaped metal plates, ensuring that a stable uprighting force is maintained throughout the entire well section when the wellbore size changes, thus solving the problem of wellbore wall adhesion failure caused by insufficient support force from a single spring in traditional structures.

[0016] 2. This invention adopts a pure mechanical transmission and segmented elastic support structure, which can eliminate the hidden danger of metal contact plate deformation or failure under high temperature environment, and ensure that the robotic arm can still open and close stably under extreme well temperature and strong vibration conditions, avoiding instrument accidents caused by mechanical jamming.

[0017] 3. The adjusting sleeve and the clamping sleeve are threaded together, allowing for axial adjustment of the spring compression along the mandrel, thus flexibly controlling the support force. This design simplifies the complex adjustment process relying on limit switches in traditional structures, significantly improving operational efficiency and adapting to the rapid response requirements of complex well conditions.

[0018] 4. The roller surface is coated with a wear-resistant coating, and its axis is perpendicular to the mandrel, which reduces wear when rubbing against the well wall and extends its service life. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a novel centralizer structure according to this utility model;

[0020] Figure 2 This is a top view of a novel straightening device structure according to this utility model;

[0021] Figure 3 This utility model relates to a novel centralizer structure. Figure 2 A sectional view;

[0022] Figure 4 This is a schematic diagram of the roller arm fixing sleeve of a novel straightener structure of this utility model at one angle;

[0023] Figure 5 This is a schematic diagram of the roller arm fixing sleeve of a novel straightener structure according to this utility model from another angle;

[0024] Figure 6 This is a cross-sectional view of the mandrel of a novel centralizer structure according to this utility model;

[0025] The components in the attached diagram are labeled as follows: 1. Mandrel; 1a. Boss; 2. Roller arm retaining sleeve; 2a. Long groove; 2b. Short groove; 2c. Through hole; 3. Spring; 4. Compression screw sleeve; 5. Adjusting screw sleeve; 6. Upper roller arm; 6a. Protrusion; 7. Lower roller arm; 8. Pin; 9. Roller; 10. Spring piece; 11. Retaining ring; 11a. Stud. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0027] Example:

[0028] As attached Figure 1 , 2As shown in Figures 3 and 4, this utility model relates to a novel straightener structure, comprising: a spindle 1 with a boss 1a at the middle of its outer side; two bosses 1a are provided for limiting the roller arm fixing sleeve 2; two roller arm fixing sleeves 2 are provided, respectively fitted onto the spindle 1 and located on both sides of the boss 1a, with a plurality of staggered long grooves 2a and short grooves 2b at one end of the roller arm fixing sleeve 2; a spring 3 is fitted onto the spindle 1 and located between the roller arm fixing sleeve 2 and the spindle 1; a clamping screw sleeve 4 is provided at the end of the roller arm fixing sleeve 2; an adjusting screw sleeve 5 is fitted between the spindle 1 and the clamping screw sleeve 4, the position of which can be adjusted along the axial direction of the spindle 1; the two ends of the spindle 1 are provided with threaded structures for fixing the adjusting screw sleeve 5 and the clamping screw sleeve 4. The upper roller arm 6 and the lower roller arm 7 are hinged in the long groove 2a and the short groove 2b, respectively, and are movably connected by the pin 8. A roller 9 is sleeved on the pin 8. A spring 10 is fixed on the upper roller arm 6. A retaining ring 11 is sleeved on the spindle 1 and located at both ends of the spring 3, and several studs 11a are fixed on its surface. A protrusion 6a is provided at the end of the upper roller arm 6 that is connected to the roller arm fixing sleeve 2. The protrusion 6a abuts against the studs 11a of the retaining ring 11. A through hole 2c is opened at the bottom of the long groove 2a. When the upper roller arm 6 is compressed, the protrusion pushes the studs 11a to move, thereby pushing the spring 3 to contract. The boss 1a is used to axially limit the roller arm fixing sleeve 2.

[0029] Furthermore, the long groove 2a and short groove 2b of the roller arm fixing sleeve 2 are evenly distributed in a staggered manner along the circumference.

[0030] Furthermore, the adjusting sleeve 5 and the clamping sleeve 4 are connected by threads, and adjusting their axial position allows the centralizer to adapt to wellbores of different diameters.

[0031] Furthermore, the number of studs 11a of the retaining ring 11 is the same as the number of long slots 2a, and each stud 11a corresponds to a protrusion 6a in a long slot 2a.

[0032] Furthermore, the spring 10 is an arc-shaped metal sheet, which is fixed to the upper roller arm 6 to provide a restoring elastic force. When the centralizer is used for applications with a relatively small diameter, the spring 10 abuts against the long groove 2 when the upper roller arm 6 retracts to a certain extent, providing a certain elastic force to the centralizer.

[0033] Furthermore, the diameter of the through hole 2c is larger than the diameter of the stud 11a, allowing the stud 11a to move axially within the through hole 2c.

[0034] Furthermore, the outer surface of roller 9 is coated with a wear-resistant coating, and its axis is perpendicular to the axis of mandrel 1. The wear-resistant coating significantly reduces the wear rate when the roller rubs against the well wall, extends the service life of the roller, and reduces the frequency of downhole replacement. The design of the roller axis being perpendicular to the mandrel ensures that it is pure rolling friction when in contact with the well wall, reducing energy loss and heat accumulation caused by sliding friction and improving logging efficiency.

[0035] Working principle and operation process

[0036] When the wellbore size is large, the two roller arm fixing sleeves 2 are fitted onto the mandrel 1, and the adjusting screw sleeve 5 is adjusted to a suitable position on the mandrel 1. The clamping screw sleeve 6 is used to fix the positions of the roller arm fixing sleeves 2 and the adjusting screw sleeve 5. When the centralizer acts on the wellbore, the upper roller arm 6 and the lower roller arm 7 are compressed, and the protrusion 1a of the upper roller arm abuts against the stud 11a, pushing the spring compression 3 to compress. When the wellbore size is small, the angle between the upper roller arm 6 and the mandrel 1 decreases, causing the spring piece 10 to contact the bottom surface of the long groove 2a, providing support for the upper roller arm 6.

[0037] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A novel centralizer structure, characterized in that, include: The spindle (1) has a boss (1a) on the middle part of its outer side; The roller arm fixing sleeve (2) is sleeved on the spindle (1), and one end of it is provided with several staggered long grooves (2a) and short grooves (2b); Spring (3) is sleeved on spindle (1) and located between roller arm fixing sleeve (2) and spindle (1); clamping screw sleeve (4) is located at the end of roller arm fixing sleeve (2); Adjusting sleeve (5) is fitted between mandrel (1) and clamping sleeve (4), and its position can be adjusted along the axial direction of mandrel (1); The upper roller arm (6) and the lower roller arm (7) are respectively hinged in the long groove (2a) and the short groove (2b), and the upper roller arm (6) and the lower roller arm (7) are movably connected by a pin (8); a roller (9) is sleeved on the pin (8); A spring clip (10) is fixed to the upper roller arm (6); A retaining ring (11) is sleeved on the spindle (1) and located at both ends of the spring (3), and several studs (11a) are fixed on its surface; The upper roller arm (6) is connected to the roller arm fixing sleeve (2) at one end, which is provided with a protrusion (6a) and the protrusion (6a) abuts against the stud (11a) of the retaining ring (11); A through hole (2c) is provided at the bottom of the long groove (2a); The boss (1a) is used to axially limit the roller arm fixing sleeve (2).

2. The novel centralizer structure according to claim 1, characterized in that: The long groove (2a) and short groove (2b) of the roller arm fixing sleeve (2) are evenly distributed in a staggered manner along the circumference.

3. The novel centralizer structure according to claim 1, characterized in that: The adjusting sleeve (5) and the clamping sleeve (4) are connected by threads to adjust their axial position to change the compression of the spring (3).

4. The novel centralizer structure according to claim 1, characterized in that: The number of studs (11a) of the retaining ring (11) is the same as the number of long slots (2a), and each stud (11a) corresponds to a protrusion (6a) in a long slot (2a).

5. The novel centralizer structure according to claim 1, characterized in that: The spring (10) is an arc-shaped metal sheet, which is fixed to the upper roller arm (6) to provide a reset spring force.

6. The novel centralizer structure according to claim 1, characterized in that: The diameter of the through hole (2c) is larger than the diameter of the stud (11a), allowing the stud (11a) to move axially within the through hole (2c).

7. The novel centralizer structure according to claim 1, characterized in that: The outer surface of the roller (9) is provided with a wear-resistant coating, and its axis is perpendicular to the axis of the spindle (1).

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