SU1384703A1 - Arrangement for stabilizing borehole direction - Google Patents

Abstract

The invention relates to the field of drilling equipment and allows to increase the accuracy of drilling the oblique-rectilinear section of the wellbore (C) by overlapping the axis of the bit D) with the axis C and ensuring that the lateral force acting on the bit is zero. The device includes D 1, a tubular body (TC) rigidly connected with it.

Description

-

with

(L

: oh

four

Phi (.1

2. Pa eccentrically to the axis of TC 2, a support element of 3 g is installed. Blades and symmetrically located inclined locking teeth are mounted. The direction of their inclination is opposite to the direction of eccentricity of element 3. The value of eccentricity is determined from a special expression. The blades are made in the form of two straight diaphragms located diametrically in the plane of symmetry, whose working surface is obregonana in a circular cylinder and has a diameter equal to the diameter of L 1. During the drilling process, TC 2 is bent so that the axis D 1 aligns with the axis C. The transverse force on D 1 will be zero. Chisel destroys the rock in the direction of its axis. T. obr., The direction of a trunk With will remain. The displacement of TC 2 is prevented by the interaction of the teeth with the walls of C. 5 Il.

The invention relates to a drilling technique and can be used to guide oblique-straight sections of a well.

The purpose of the invention is to improve the accuracy of the drill 1 in an inclined-straight section of the wellbore by aligning the axis of the bit with the axis of the well and ensuring that the lateral force acting on the bit is zero.

Fig. 1 shows a device for stabilizing the direction of a well bore, a general view; figure 2 is a section of LA in figure 1; 3-5, variants of the connection of the device with the bottom of the drill string.

The device for stabilizing the direction of the borehole includes a bit 1, a tubular body 2 rigidly connected with it, a supporting element 3 rotatably mounted thereon, provided with blades 4 made in the form of two diametrically oppositely arranged in the plane of symmetry of the straight bars with the working surface 5, which is formed by a circular cylinder, and the diameter of the working surface 5 is equal to the diameter of the bit 1.

The supporting element 3 is mounted eccentrically with respect to the axis of the housing 2, and the value of the eccentricity is determined from the expression

l

  24 E1 where q is the transverse component

weight of the unit of body length sr / m

0

five

0

five

0

five

L is the device length, m;

. E is the modulus of elasticity

 I - moment of inertia of the hull section, m

The supporting element 3 is provided with symmetrically arranged inclined locking teeth 6 for interacting with the borehole wall, the direction of which is opposite to the direction of eccentricity of the stabilizing element 3.

The support member 3 is mounted on bearings 7, the housing 2 is provided with a concentric thread 8 for communication with the lower part of the drill string.

A device for stabilizing the direction of the borehole operates as follows.

The device is connected with a thread 8 to the lower part of the drill string, which may include, for example, a support-centering element 9 (Fig. 3), a flexible link 10 (Fig. 4) or a hinge 11 (Fig. 3). In all cases, the diameter and location of the support-centering element 9, the length and stiffness of the flexible link 10, as well as the location of the hinge 11 are selected using known methods so that the bending moment M is equal at the junction of the device with the drill string derived from

“.

where R. is the axial load on the bit, kN;

Since the end of the previous excavation of the rock forming the borehole wall, when interacting with the prostate fluid, the diameter of the borehole before the start of the next injection is usually larger than the diameter of the bit 1. Therefore, when the device is lowered into the inclined borehole, the support element 3 rotates on bearings 7, it will occupy a position corresponding to the minimum energy of the system, in which the upper part of the housing 2 will be in the lowest position, and the blades 4 in the vertical position,

During the drilling process, under the action of longitudinal and transverse forces, the casing is bent in such a way that the axis of the bit 1 is aligned with the axis of the well, and the transverse force acting on the bit 1 is zero. At the same time, the bit destroys the rock in the direction of its axis, and since the axis of the bit coincides with the axis of the well, the existing direction of its bore is maintained.

The displacement of the housing 2 will be eliminated due to the interaction of the inclined locking teeth 6 with the borehole wall,

Claims (1)

Invention Formula A device for stabilizing the direction of a well bore, including a chisel, a tubular body rigidly connected to it, is outdated on it with the possibility of turning a supporting element with blades, whose working surface is formed by a circular cylinder, o. This is because in order to increase the drilling accuracy of the oblique-rectilinear section of the borehole by aligning the axis of the bit with the axis of the well and ensuring that the transverse force acting on the bit is zero, the support element is installed eccentrically to the axis of the body and has symmetrically located inclined fixing teeth for interaction with the borehole wall, the direction of the nak, opposite to which of the eccentricity of the support element, symmetric bones of straight strips, the diameter of the working surface of which is equal to the diameter of the chisel, and the eccentricity value g is determined from BUT- where q is the transverse component of the weight of a unit of body length, kg / m; L is the device length, m; Е - modulus of elasticity, kg / m; I is the moment of inertia of the hull sections, m 2 FIG. 3 FIG. five