CN108019163A - Elastic ball-type casing and drill pipe protector - Google Patents

Abstract

The invention provides an elastic ball type casing and drill pipe protector, which includes a central sleeve body, a fixed rib, a leaf spring and balls, and is mainly used in the drilling process. When the serious well section is affected by the wellbore trajectory and abuts against the inner wall of the casing, the ball can replace the sliding friction between the traditional drill pipe and the casing with rolling friction, thereby reducing the wear of the casing, and the fixed rib is evenly installed on the center casing On the outer wall of the body, the leaf spring installed inside provides good elastic support for the ball, reducing the rotational torque of the drill string and negative pressure when pulling out of the drill string, ensuring that the WOB value is not distorted, and ensures that when drilling in a seriously curved well section The smoothness of the drill pipe passing, the rolling motion of the ball on the inner surface of the casing, due to the uniform elastic force it receives, can ensure the synchronous rotation of the center sleeve and the drill pipe, reducing the impact of the center sleeve and the drill The friction between the rods reduces the degree of wear on the drill rod.

Description

Elastomeric Ball Bushing and Drill Pipe Protectors

technical field

The invention provides a casing and a drill pipe protector used in drilling operations, and specifically provides a protective device that is attached to the casing when the drill pipe is affected by its own weight in an inclined well section or is affected by the wellbore trajectory in a seriously curved well section. When the inner wall of the pipe is used, the elastic ball type casing and the drill pipe protector are used to reduce the wear degree of the drill pipe to the casing and the wear degree of the drill pipe itself.

Background technique

During drilling, the drill string is pulled toward the upper side of the wellbore under tension, and as the string rotates, it causes the upper side of the casing to wear. Under the action of gravity and weight-on-bit, the drill string is pressed against the lower side of the casing. As the drill pipe and casing slide and rotate, the lower side of the casing will be worn.

After the casing is worn, its anti-extrusion strength and internal pressure resistance decrease, resulting in deformation of the casing, which seriously affects the passage of drilling and testing tools, and cannot complete further work. serious problem.

In order to effectively solve the problem of casing wear during drilling, it is necessary to install a casing protector on the drill pipe during actual construction to avoid direct contact between the drill pipe and the inner wall of the casing. Since the hardness of the material used for the casing protector is lower than The material of the casing is hard, so when the casing protector moves relative to the casing, the casing protector will be worn instead of the casing itself, thereby effectively reducing the wear of the casing.

In addition to the above features, the elastic ball type casing and drill pipe protector have the leaf springs in the fixed ribs to provide uniform elastic support for the balls, reduce the drill pipe rotation torque and pull-out negative pressure, and ensure that the WOB value is consistent. Distortion, to ensure the fluency of drill pipe passage when drilling in seriously curved well sections. The ball rolls on the inner surface of the casing, and because of the uniform elastic support force, it ensures the synchronous rotation of the center casing and the drill pipe, reducing the friction between the center casing and the drill pipe, thereby reducing the The degree of wear on the drill pipe. The material hardness of the center sleeve body is lower than that of the drill pipe, so the drill pipe will not be worn during the drilling process. The uniform installation of 18 fixed ribs on the protector ensures the uniformity of drilling fluid flowing in the wellbore, and is more conducive to controlling the pressure in the wellbore.

Contents of the invention

The object of the present invention is to provide an elastic ball casing and a drill pipe protector, which can effectively reduce the wear degree of the drill pipe to the casing and the wear degree of the drill pipe itself during the drilling process.

In order to achieve the above object, the present invention takes the following technical solutions:

(1) An elastic ball type bushing and drill pipe protector, the protector includes a central sleeve body, fixing ribs, leaf springs and balls.

(2) In each fixing rib, a leaf spring with a plurality of middle holes is arranged at a position close to the outer wall surface of the center sleeve.

(3) The surface of the center hole on the leaf spring in each fixed rib is polished into a concave spherical surface that matches the ball, providing uniform elastic support for the ball, reducing the rotational torque of the drill pipe and the negative pressure for pulling out, ensuring The weight-on-bit value is not distorted, ensuring the fluency of drill pipe passage when drilling in severely curved well sections.

(4) The central angle between every two fixed ribs is 20°, and a total of 18 fixed ribs are evenly installed on the outer wall of the center casing. The uniform installation method can ensure the homogeneity of the drilling fluid flowing in the wellbore , which is beneficial to control the pressure in the wellbore.

(5) Each ball corresponds to a middle hole on the leaf spring.

(6) Each ball is designed to be hollow. Compared with solid balls, it reduces the weight of the protector itself and reduces the pressure of the protector on the sleeve, thereby reducing the wear of the sleeve.

(7) When each ball is in contact with the inner wall of the casing, the rolling friction of the ball replaces the traditional sliding friction between the drill pipe and the inner wall of the casing, which greatly reduces the wear of the casing.

(8) Each ball rolls on the inner surface of the casing, and because of its good elastic support force, it ensures the synchronous rotation of the center sleeve and the drill pipe, reducing the friction between the center sleeve and the drill pipe resistance, thereby reducing the degree of wear on the drill pipe.

(9) The material hardness of each ball is lower than that of the casing. When the balls are in contact with the casing, it is the balls that wear and tear, thereby reducing the wear of the casing.

(10) The material hardness of the center casing is lower than that of the drill pipe. When the drill pipe rotates in the center casing, the center casing will be worn, thereby reducing the degree of wear of the drill pipe.

Advantages of the present invention:

(1) The balls installed in the fixed ribs of the present invention replace the traditional sliding friction between the drill pipe and the inner wall of the casing with rolling friction, thereby reducing the wear of the casing to a greater extent.

(2) The ball in the present invention is designed to be hollow. Compared with the solid ball, it reduces the weight of the protector itself, reduces the pressure of the protector acting on the casing, thereby reducing the wear degree of the casing.

(3) In the present invention, the leaf spring provides a uniform elastic support force for the ball, which reduces the rotational torque of the drill pipe and the negative pressure when pulling out of the drill, ensures that the pressure on bit is not distorted, and ensures the passage of the drill pipe when drilling in a seriously curved well section. fluency.

(4) In the present invention, each ball rolls on the inner surface of the casing, and because it is subjected to a uniform elastic support force, it ensures that the center sleeve and the drill pipe rotate synchronously, reducing the distance between the center sleeve and the drill pipe. The friction between them reduces the degree of wear on the drill pipe.

(5) The evenly distributed arrangement of 18 fixing ribs in the present invention can ensure the homogeneity of the drilling fluid flowing in the wellbore, which is beneficial to control the pressure in the wellbore.

Description of drawings

Figure 1 is a top view of the present invention.

Figure 2 is a front view of the present invention.

Detailed ways

The present invention will be further described below in conjunction with accompanying drawing.

The central sleeve body 1 of the present invention is installed on the designated position of the drill rod, and can roll relative to the drill rod.

The hardness of the material used in the center sleeve 1 of the present invention is lower than that of the drill pipe, so when the center sleeve 1 and the drill pipe roll relative to each other, the center sleeve 1 will be worn.

The fixing ribs 2 of the present invention are evenly installed on the outer wall surface of the center casing 1, the central angle between every two fixing ribs 2 is 20°, and there are 18 fixing ribs 2 evenly distributed in total.

In the present invention, the 18 fixed ribs 2 are evenly distributed in an installation manner, which can ensure the homogeneity of the drilling fluid flowing in the wellbore, and is beneficial to control the pressure in the wellbore.

In each fixed rib 2 of the present invention, a leaf spring 4 with a plurality of middle holes is installed, and each middle hole is ground into a concave spherical surface matched with the ball 3, which can provide a uniform elastic support force for the ball 3, reducing the need for drilling. Rod rotation torque and pull-out negative pressure ensure that the WOB value is not distorted, and ensure the smoothness of drill pipe passage when drilling in seriously curved well sections.

Each ball 3 corresponds to a middle hole on the leaf spring 4 in the present invention.

In the present invention, each ball 3 performs rolling motion on the inner surface of the casing, replacing the traditional sliding friction between the drill pipe and the inner wall of the casing by means of rolling friction, which greatly reduces the degree of wear of the casing .

In the present invention, each ball 3 is designed to be hollow. Compared with solid rolling balls, it reduces the weight of the protector itself, reduces the pressure of the protector acting on the casing, thereby reducing the wear of the casing.

In the present invention, the material hardness of each ball 3 is lower than that of the sleeve, and when the ball 3 contacts the sleeve, the ball 3 will be worn, thereby reducing the wear of the sleeve.

Claims (10)

1. a kind of elastic ball-type casing and drill pipe protector, including center body, fixing rib, leaf spring and ball, it is special Sign is, in each fixing rib, the leaf spring one with multiple mesoporous is being provided with the external wall position of center.

2. elastic ball-type casing according to claim 1 and drill pipe protector, it is characterised in that on leaf spring Hole hole face be all polished into the matched concave spherical surface of ball, provide uniform elastic anchorage force for ball, reduce drilling rod rotation Moment of torsion and trip-out negative pressure, it is ensured that the pressure of the drill value is undistorted, ensures to bore the fluency for meeting that drilling rod passes through when bending serious well section.

3. elastic ball-type casing according to claim 1 and drill pipe protector, it is characterised in that each two fixing rib it Between central angle be 20 °, in the outside wall surface of center body altogether 18 fixing ribs are uniformly installed.

4. elastic ball-type casing according to claim 3 and drill pipe protector, it is characterised in that 18 fixing ribs are uniform Mounting means can ensure the homogenieity that drilling fluid flows among pit shaft, be conducive to control pit shaft in pressure.

5. elastic ball-type casing according to claim 1 and drill pipe protector, it is characterised in that every ball corresponds to steel A mesoporous on flat spring.

6. elastic ball-type casing according to claim 5 and drill pipe protector, it is characterised in that every ball is designed as It is hollow, compared with solid spin, which alleviates the weight of protector itself, reduce protector and act on pressure on casing, So as to reduce the degree of wear of casing.

7. elastic ball-type casing according to claim 6 and drill pipe protector, it is characterised in that when in ball and casing When wall is in contact, ball instead of the sliding friction between traditional drilling rod and internal surface of sleeve pipe with rolling friction, greatly reduce The degree of wear of casing.

8. elastic ball-type casing according to claim 7 and drill pipe protector, it is characterised in that ball table in casing Rolling movement is done in face, and since it is subject to uniform elastic anchorage force to act on, ensure that center body synchronizes rotation with drilling rod Transhipment is dynamic, the frictional resistance between center body and drilling rod is reduced, so as to reduce the frayed degree of drilling rod.

9. elastic ball-type casing according to claim 8 and drill pipe protector, it is characterised in that the material of every ball Hardness is less than the material hardness of casing, and when ball is in contact with casing, what is worn will be ball, so as to reduce casing The degree of wear.

10. elastic ball-type casing according to claim 1 and drill pipe protector, it is characterised in that the material of center body Matter hardness is less than the material hardness of drilling rod, and when drilling rod is rotated in center body, what is worn will be center body, So as to reduce the degree of wear of drilling rod.