RU2805025C1 - Stabilizing assembly for drilling - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention is related to the field of directional drilling of wells, namely to devices for stabilizing the direction of the wellbore and reducing the intensity of the natural curvature of wells. The stabilizing assembly for drilling contains a diamond bit with an eccentricity of the cutting part of the matrix end and a drill pipe with a displaced centre of mass of the cross section, containing remote segments. A diamond bit with an eccentricity of the cutting part of the die end and a drill pipe with a displaced centre of mass of the cross section are located in the assembly in such a way that half of the end of the matrix of the diamond bit with an eccentricity of the cutting part of the die end with a smaller area is placed so that its geometric centre is at 180° with respect to the geometric centre of the remote segments.

EFFECT: increased stabilizing ability of the drilling assembly.

1 cl, 2 dwg

Description

The invention relates to the field of directional drilling of wells, namely to devices for stabilizing the direction of the wellbore and reducing the intensity of natural curvature of wells.

At the moment, when conducting drilling operations, there is a problem of undercutting the ore body within the tolerance circle of the roof of the formation according to the geological specifications at great depths. This happens due to the deviation of the wellbore from the design direction due to the natural curvature of the wellbore.

In modern conditions, exploration and mining of mineral resources is carried out at ever-increasing depths. Under these conditions, the wells being constructed reach a considerable length, and their trajectory is subject to strict requirements to comply with the design direction of the wellbore, which in conditions of drilling anisotropic rocks appears to be a serious problem.

An analogue of the proposed technical solution is a well-known drilling assembly for drilling, containing a bit, a centralizer, a pipe with a displaced center of mass of the cross-section, centering elements, a GV hydraulic hammer (Modern technologies for drilling for solid minerals: textbook / V.V. Neskoromnykh, M.S. Popova, P.G. Petenev [and others]. - Krasnoyarsk: Siberian Federal University, 2020. - 340 pp. Page 106).

The disadvantage of this technical solution is its low efficiency in combination with core drilling, as well as the fact that the dynamic stabilization of this arrangement occurs only from the action of the pipe with a displaced center of mass of the cross-section, which is not enough to effectively stabilize the wellbore during the drilling process.

A utility model is known (RU No. 163419, E21B 17/00. Application 01/23/2016. Published 07/20/16) containing a metal body made with a ring-shaped cross-section with two remote segments located with their axes relative to each other to form flat longitudinal sections of the outer surface of the pipe, while the remote segments forming flat longitudinal sections are located along the length of the pipe body, while leaving the central section of the pipe body intact.

However, drilling efficiency is not achieved.

The prototype of the proposed invention is a diamond bit (RU No. 171734, E21B 10/48. Application 01/09/2017. Published 06/13/2017) containing a threaded body, flushing channels of the same cross-sectional area and a matrix with diamond-containing sectors of three geometric shapes in in the form of ring segments - standard, large and small, with large and small diamond-containing sectors located alternately at the end of the matrix, which ensures the eccentricity of the cutting part of its end.

The disadvantage of the prototype is that it imparts a stable type of movement around the well axis to only part of the drilling assembly at the installation site of this technical device.

The objective of this invention is to increase the stabilizing ability of the drilling assembly

This is achieved by the fact that a stabilizing drilling assembly containing a diamond bit with an eccentricity of the cutting part of the matrix end, a drill pipe with a displaced center of mass of the cross section, according to the invention, a diamond bit with an eccentricity of the cutting part of the matrix end and a drill pipe with a displaced center of mass of the cross section are located as part of the arrangement in such a way that half of the matrix end of the diamond bit with the eccentricity of the cutting part of the matrix end with a smaller area of the diamond-containing matrix is placed with its geometric center at 180° with respect to the geometric center between the remote segments along the body of the drill pipe with a displaced center of mass of the cross-section.

This technical solution is based on experimental data obtained at the JSC Krasnoyarsk Geology enterprise when drilling with diamond bits with eccentricity of the cutting part of the matrix end, and with drill pipes with a displaced center of mass of the cross section, as well as bench studies carried out at the Department of Technology and Exploration Engineering of the Siberian Federal University which made it possible to draw a conclusion about the direction of action of the stabilizing forces during the drilling process both with a diamond bit with the eccentricity of the cutting part of the matrix end, and with a drill pipe with a displaced center of mass of the cross section.

Analysis of the results of experiments and bench studies obtained during testing of a diamond bit with an eccentricity of the cutting part of the matrix end and a drill pipe with a displaced center of mass of the cross section showed that the place of contact of such pipes with the borehole wall is observed from the side of remote segments of the pipe body with a displacement in the direction of rotation.

Since the stabilizing effect depends largely on the type of movement of the drilling assembly and the rock-cutting tool, the nature of this movement can be judged by the wear of the surface of various elements of the drilling assembly.

Similar experiments on side surface wear were carried out with a diamond bit with an eccentricity of the cutting part of the matrix end, which showed that the contact point of the matrix and the body of the diamond bit with the borehole wall is observed from the side of half the end of the diamond bit matrix, which has a smaller area.

Analyzing the data characterizing the operating principle of drill pipes with a displaced center of mass of the cross section and diamond bits with an eccentricity of the cutting part of the matrix end in the well, and comparing the results of studying the patterns of wear of such assemblies, we can conclude that the maximum effect of stabilizing the direction of the well will be achieved by their joint installation with synchronization of pressure points as part of one arrangement.

The invention is illustrated in Fig. 1-2. Fig. 1 - general view of the stabilizing arrangement. Fig. 2 - section along A-A Fig. 1, showing the orientation of the diamond bit with the eccentricity of the cutting part of the matrix end relative to the drill pipe with a displaced center of mass of the cross section as part of the assembly.

The drilling assembly consists of a diamond bit with an eccentricity of the cutting part of the end of the matrix 1, a centralizer 2, a drill pipe 3 with a displaced center of mass of the cross section. The diamond-containing matrix is divided at the end of the bit into half the end with a smaller area of the diamond-containing matrix 4 and half with a larger area of the matrix 5, while the diamond bit with the eccentricity of the cutting part of the end of the matrix contains flushing windows 7. The drill pipe 3 with a displaced center of mass of the cross section contains two remote segments 6, while the remote segments forming flat longitudinal sections are located along the length of the pipe body, leaving the central section of the pipe body untouched. Half of the end face of the diamond crown matrix with a smaller area 4 has a geometric center 8. The removed segments 6 have a geometric center 9.

During the drilling process, the drilling assembly receives axial force and torque from the drill pipe string. During the drilling process, the centralizer 2 maintains the diameter of the well and centers the drilling assembly in the well. In the process of rotation, the drill pipe 3 with a displaced center of mass of the cross section due to the remote segments 6, creates conditions for rotation of the string around the well axis due to the action of centrifugal forces acting on the assembly. At the same time, the diamond bit 1 with the eccentricity of the cutting part of the matrix end, which is created due to the fact that the matrix is divided into half the end with a smaller area of the diamond-containing matrix 4 and half with a larger area of the diamond-containing matrix 5, is pressed against the borehole wall with its outer surface, which leads to uniform milling of the borehole wall and reduces the intensity of the borehole curvature. In this case, the diamond bit with the eccentricity of the cutting part of the end of the matrix 1 together with the drill pipe with a displaced center of mass of the cross section 3 as part of the arrangement are oriented relative to each other in such a way that half of the end of the matrix of the diamond bit with the eccentricity of the cutting part of the end of the matrix with a smaller area is placed by its geometric center 8 at 180° relative to the geometric center 9 of remote segments 6. (Fig. 2). Thus, the area of pressure of the assembly from the side of the diamond bit with the eccentricity of the cutting part of the end of the matrix 1 and the drill pipe with a displaced center of mass of the cross section 3 will coincide in direction and bring the entire lower part of the assembly into rotation around the well axis with maximum stabilizing ability during uniform milling well walls around the perimeter.

The above actions ensure synchronous operation of two stabilizing devices as part of one arrangement and will help increase the stabilizing effect of each of them.

This technical solution will make it possible to minimize the intensity of natural curvature when drilling wells in anisotropic rocks, sections with alternating rocks in hardness, in wells with the intersection of geological layers, and in general will reduce the cost of drilling operations.

Claims (1)

A stabilizing assembly for drilling containing a diamond bit with an eccentricity of the cutting part of the matrix end, a drill pipe with a displaced center of mass of the cross section containing remote segments, characterized in that the diamond bit with an eccentricity of the cutting part of the matrix end and a drill pipe with a displaced center of mass of the cross section are located as part of the arrangement in such a way that half of the matrix end of the diamond bit with the eccentricity of the cutting part of the matrix end with a smaller area is placed with its geometric center at 180° relative to the geometric center of the remote segments.