CN201083088Y - Casing wear reducer - Google Patents

Abstract

The utility model discloses a casing wear reducer for downhole drilling tools used in oil drilling. There are upper joints, lower joints and a tool body connected to the lower and upper joints in the casing, and the jacket is sheathed on the outer wall of the tool body. Set more than one continuous friction pair on the inner wall of the jacket, set more than one continuous friction pair corresponding to the friction pair on the outer wall of the tool body, fix the stop ring on the outer wall of the tool body and contact with one end surface of the jacket, The jacket of the utility model does not rotate relative to the inner wall of the casing in the casing, but only slides relatively, which reduces the wear of the casing; the dynamic friction coefficient between the tool body and the non-rotating casing friction pair is very small, which can reduce the torque of the drill pipe; Rigid connection between ring and tool body for increased strength and longer life.

Description

Casing wear reducer

technical field

The utility model relates to a downhole drilling tool used for oil drilling, in particular to a casing wear reducer on the drill pipe used for reducing casing wear.

Background technique

With the development of oil drilling technology, in deep wells, ultra-deep wells, highly deviated wells, extended-reach wells and horizontal wells, the drilling time is long and the lateral force of the drill pipe joint on the casing increases, so casing and drill pipe The problem of friction and wear of joints is becoming more and more prominent, and its direct consequences are: not only lead to rapid wear and premature failure of drill pipe joints; Collapse, deformation and leakage will cause the whole well to be scrapped in severe cases.

The existing various casing wear reducers used in China to prevent casing wear are all designed to reduce the wear of casing and drill pipe joints, and can be roughly divided into three categories: 1. Spraying wear-resistant paint on drill pipe joints However, this technology does not fundamentally solve the wear problem between the drill pipe joint and the casing, so the effect is not very satisfactory; 2. Drill pipe protector: the advantage of this technology is that it reduces the distance between the drill pipe and the casing. 3. Rotary drill string joint: This technology is to install hard alloy on the surface of the friction pair to make it a discontinuous hard surface. The rotary drill string joint uses hard alloy as the bearing , because the surface of its friction pair is not continuous, so in the process of use, the relative impact force is relatively large, and the service life is not very long, generally 600-800 hours in actual use.

Contents of the invention

The purpose of the utility model is to provide a casing wear reducer with good wear resistance and long service life in order to overcome the deficiencies of the prior art.

The technical scheme adopted by the utility model is: there are upper joints and lower joints and a tool body connected to the lower and upper joints in the casing, the outer wall is set on the outer wall of the tool body, and more than one continuous friction pair is set on the inner wall of the outer sleeve. More than one continuous friction pair corresponding to the friction pair is arranged on the outer wall of the tool body, and the retaining ring is fixed on the outer wall of the tool body and is in contact with one end surface of the casing.

The jacket of the utility model does not rotate relative to the inner wall of the casing in the casing and only slides relative to it, which reduces the wear of the casing; the dynamic friction coefficient between the tool body and the non-rotating casing friction pair is very small, which can reduce the torque of the drill pipe; The rigid connection between the stop ring and the tool body can increase the strength, and the service life can reach more than 1800 hours; the impact force is reduced by 40%.

Description of drawings

The utility model is described in further detail below in conjunction with accompanying drawing and specific embodiment.

Fig. 1 is the structural representation of the utility model.

Detailed ways

As shown in Figure 1, the drill pipe is inside the casing 3, the left end of the tool body 2 is connected to the upper joint 1, and the right end is connected to the lower joint 8, and a jacket 5 is set on the outer wall of the tool body 2, and the inner wall of the jacket 5 is set More than one continuous friction pair 6, and one or more continuous friction pairs 7 corresponding to the friction pair 6 are provided on the outer wall of the tool body 2. There are continuous grooves or rings on the surfaces of the friction pairs 6 and 7, and high-carbon cobalt-based hard alloy wear-resistant materials are used in the grooves or rings for surfacing, welding, electric welding or spray welding of high-strength matrix alloy materials ( 40CrNiMoA), which can improve the wear resistance potential of the material and reduce the cost. The retaining ring 4 is welded on the outer wall of the tool body 2 and is in contact with one end surface of the jacket 5 . The jacket 5 of the present utility model is in contact with the inner wall of the casing 3, and the tool body 2 rotates together with the drill pipe, so that the jacket 5 only slides relative to the inner wall of the casing 3 in the casing 3, and the outer casing 5 and the casing 3 The inner wall does not rotate relative to each other, thereby reducing the wear of the casing 3. Due to the very small dynamic friction coefficient between the body 5 and the non-rotating casing friction pair, and the unique self-lubricating properties of the drilling fluid, the torque of the drill pipe is effectively reduced. The utility model adopts sliding bearing type continuous friction pair material wear reduction technology, open drilling fluid lubrication, the whole set of tools is made of high-strength alloy steel, the retaining ring 4 and the tool body 2 are rigidly connected, the strength is high, and downhole accidents are not easy to occur.

Claims (3)

1. A casing wear reducer, which has an upper joint (1) and a lower joint (8) and a tool body (2) connected to the lower and upper joints in the casing (3), characterized in that: the outer sleeve (5) On the outer wall of the tool body (2), set more than one continuous friction pair (6) on the inner wall of the outer casing (5), and set more than one corresponding friction pair (6) on the outer wall of the tool body (2) The continuous friction pair (7). 2. The bushing wear reducer according to claim 1, characterized in that: the retaining ring (4) is fixed on the outer wall of the tool body (2) and is in contact with one end surface of the casing (5). 3. The bushing wear reducer according to claim 1, characterized in that: there are continuous grooves or rings on the surfaces of the friction pair (6) and the friction pair (7), and surfacing welding is carried out in the grooves or rings. Wear-resistant material.

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