SU768927A1 - Centering guide for low portion of drilling tool - Google Patents

Description

one

The invention relates to the drilling of wells and is used as an integral part of the lower part of a drilling tool, fastened, for example, to a downhole motor.

Downhole motor centralizers are known, which are also subs that connect separate parts of a downhole motor, for example engine sections 1.

The disadvantage is that the said centralizers in the drilling tool always occupy a permanent place and therefore there is no possibility of adjusting the direction of the well bore when drilling (especially inclined) by moving the centralizers along the downhole motors. In addition, it is not possible to use such a downhole motor without these centralizers, and this imposes a restriction on the use of motors.

A centralizer for the lower part of a drilling tool is known, which includes a housing, a split ring mounted with the possibility of interaction with its inner surface, and a lock of its position associated with the housing by a thread {2.

However, the fastening of such a centralizer is not reliable enough.

The purpose of the invention is to increase the reliability of fastening of the centralizer.

This goal is achieved by the fact that the split ring has cam projections, the housing along the inner surface is provided with an annular groove for accommodating 5 cam projections of the split ring and grooves inclined to the vertical axis of the housing and intersecting the annular groove for accommodating the cam projections of the split

10 rings.

At least two annular grooves can be made on the inner surface of the housing. On cam ledges split

5 rings can be made holes, and through slots are made in the case where the annular grooves are located.

FIG. 1 shows a centralizer for the bottom of a boring tool, longitudinal

20 cut; in fig. 2-4 - sections A-A, B-B, B-B of FIG. one; in fig. 5-centralizer in axonometry.

In the centralizer housing 1 there are a split ring 2 and stoppers 3. To accommodate the split ring 2 and stoppers 3 inside the housing 1, annular grooves a are made, intersecting at an angle to the vertical axis of the housing with grooves b that extend from the upper end. For

30 convenience of mounting centralizer cam

the protrusions and split rings 2 have holes r, and in the case, in Mecte, there are ring grooves, through slots are made. In assembled form, the cam projections in split rings 2 are located in the corresponding annular groove a, which should not be. less than two, and between the cam projections are installed stoppers 3.

The centralizer works as follows.

It is installed, for example, on a downhole motor housing (not shown in the figure) in any part of it that has a recess under the clamp (not shown in the figure). In this case, split rings 2 are placed in the recess of the downhole motor housing (not shown in the figure) and a freely worn centralizer housing is pulled onto them. In this case, the cam projections in the split rings 2, moving in the inclined grooves b of the housing 1, are aligned with the selected annular groove a. After that, the body 1, at the height of the split rings 2, rotates at a certain angle. So that with the rotation of the housing 1 the split rings 2 could not turn, they are held by the mounts by the holes r through the slots d of the housing 1. To prevent the reverse spontaneous rotation and subsequent removal of the housing 1 with a ton of jaw projections into the split rings 2, stoppers are inserted into the inclined grooves 3, which occupy a space between the cam projections in the split rings 2. The oblique position of the grooves b prevents the stoppers 3 from popping out with sharp jolts of the drilling tool. Depending on which groove cam claws are installed in split rings 2, the distance between centralizer housing 1 and the lower end of the pins of the downhole motor (not shown in the drawings) will vary, thereby ensuring adjustability of the centralizer installation.

The advantages of the proposed centralizer are the ability to place the centralizer anywhere in the lower part of the drilling tool, including both at the ends and in the middle part of the downhole tool.

engine In addition, a large range of its displacement with respect to the recesses on the bottomhole motor housing allows for more correctly and efficiently solving technological problems of drilling (for example, stabilizing or changing the value of curvature in inclined wells during drilling, the drilling volume of which increases annually). At the same time, the proposed centralizer, when installed, does not require reworking of the downhole motors or their disassembly and does not destroy the downhole motor.

Claims (3)

1. A hub for the bottom of the drilling tool, including a housing that is interoperable with its inner surface is a split ring and its position lock, characterized in that, in order to increase the reliability of the centralizer attachment, the split ring has cam projections, the housing along the inner surface is provided with an annular groove to accommodate the cam projections of the split ring and grooves inclined to the vertical axis of the housing and crossing the ring groove, to place the retainer between the cam projections of the split ring. 2. A hub according to claim 1, characterized in that, in order to regulate the installation centralizer height drilling tool, on the inner surface of the body is made of at least two annular grooves. 3. The hub on the PP. 1 and 2, characterized in that, in order to simplify the mounting of the centralizer on the drilling tool, the holes are made on the cam projections of the split ring, and through slots are made in the housing at the location of the ring grooves. Source of information Acceptance of a review of expertise 1. Belev V.M. Layout of the lower part of the drill string “VNIIENG, Moscow, 1972, p. 65-67. 2. Patent. US No. 3276824, CL. 308-4, pub. 04.10.66 (prototype). .L-L FIG. 2 BB J Phi 5