RU2167256C1 - Gear to stabilize deflecting tool - Google Patents

Abstract

FIELD: mining industry, drilling of deep oil and gas wells. SUBSTANCE: gear is related to devices for orientation and stabilization of motor-deflecting tool. Gear include drill bit, motor-deflecting tool with fixing unit. The latter comes in the form of bearing tube with joint which is placed between motor-deflecting tool and bearing tube whose length is determined by calculation. EFFECT: drilling of holes with minimal deflection from design profile. 1 dwg

Description

 The device for stabilizing the diverter relates to the field of drilling deep oil and gas wells and can be used to orient and stabilize the downhole motor diverter.

 A device is known that includes a chisel, a supporting element in the form of a centralizer or decentrator, a volumetric hydraulic motor, a fixing unit located above the downhole motor with hydraulically extending support-centering elements (1) hydraulically extending to the opposite side from the action of the lower decentrator. The fixing unit is designed to offset the upper part of the downhole motor from the borehole axis and prevent its rotation.

 The known device is intended for drilling curved sections of the wellbore. When creating an axial load on the bit, a longitudinal bending of the body of the volumetric hydraulic motor occurs, which contributes to the intensive incision of the support-centering elements of the device into the borehole walls. At the same time, the movement of the drill string in the direction of drilling is significantly impeded.

 A device is known for stabilizing the position of the diverter during drilling of inclined sections of the wellbore, including a bit, a downhole diverter motor, a unit for fixing the diverter relative to the wall of the well, weighted drill pipes (2). The deflector fixation unit comprises a housing, a hydraulic unit with retractable elements in the form of roller cones reinforced with carbide teeth.

 The disadvantage of this device is the low fixing ability of the cones, especially in loose rocks. Under the action of the reactive moment on the bit and torsional vibrations of the lower part of the drill string, the deflector can rotate around its axis in the direction of the reactive moment on the deflector motor. In this case, the wellbore deviates from the design direction.

 The objective of the invention is to increase the accuracy of the design profile of the well by stabilizing the diverter motor in the direction of curvature of the wellbore.

где L, d - длина и диаметр опорной трубы соответственно, м;
R - радиус кривизны ствола скважины, м;
D - диаметр долота, м;
Q - поперечная составляющая веса единицы длины опорной трубы, кН/м;
EJ - жесткость на изгиб опорной трубы, кН/м².The problem is solved due to the fact that in the device for stabilizing the deflector, including the deflector motor with the fixation unit and the bit, the fixation unit is made in the form of a support pipe with a spatial type hinge located between the deflector motor and the support pipe, the length of which is selected from the ratio :

where L, d is the length and diameter of the support pipe, respectively, m;
R is the radius of curvature of the wellbore, m;
D is the diameter of the bit, m;
Q is the transverse component of the weight per unit length of the support pipe, kN / m;
EJ - bending stiffness of the support pipe, kN / m ² .

 The invention consists in the following. Due to the implementation of the fixing unit in the form of a support pipe with a hinge of a spatial type located between the diverter motor and the support pipe, the length of which is selected from the relation [1], the orientation of the diverter motor with a chisel in the direction of the well curvature is achieved and the directional well drilling process is ensured with a minimum deviation from the design profile.

 The drawing shows a General view of the proposed device for stabilization of the deflector, including the bit 1, the motor-deflector 2, the fixing unit, consisting of a hinge of spatial type 3 and a support pipe 4, which is rigidly connected to the drill pipe 5.

 The operation of the device for stabilizing the diverter is as follows.

 Depending on the design radius of the borehole curvature and the diameter of the bit 1, a support pipe 4 is selected and installed complete with a hinge of spatial type 3, the length of which is determined from the relation [1].

 The support pipe 4 with the estimated length orientes the diverter motor 2 with the bit 1 in the direction of the curvature of the well, occupying a position in which its lower part rests on the wall of the well in t. A, the middle part in t. B, and the upper in t. C ( Fig. 1). When drilling, there is a reactive moment of the diverter motor 2, under the action of which the latter tends to rotate around its axis. The rotation of the diverter motor 2 is prevented by the support pipe 4, which fixes the hinge of the spatial type 3 in t. A. Based on the stiffness of the support pipe 4, diameter and design length, its bending in the most loaded section is excluded (corresponds to t. B of Fig. 1) in the result of the reactive moment of the diverter motor 2.

 The support pipe 4 does not interfere with the advancement of the drill string 5 in the direction of drilling.

 A hinge of the spatial type 3 installed between the diverter motor 2 and the support pipe 4 reduces the resistance forces when the drill string 5 moves in the wellbore during tripping.

 The device for stabilizing the diverter will allow the well to be drilled with minimal deviations from the design profile, which will significantly reduce financial costs for well construction and increase the overhaul period during the operation phase.

Sources of information:
1. Pat. USA 3561549, MKI E 21 V 7/06, NCI 175/76.

 2. A.S. USSR 294923, MKI E 21 V 7/10.

Claims (1)

A device for stabilizing the deflector, including a bit, a deflector motor with a fixing unit, characterized in that the fixing unit is made in the form of a support pipe with a hinge of a spatial type, the latter being located between the deflector engine and the supporting pipe, the length of which is selected from the ratio

where L, d is the length and diameter of the support pipe, respectively, m;
R is the radius of curvature of the wellbore, m;
D is the diameter of the bit, m;
Q is the transverse component of the weight per unit length of the support pipe, kN / m;
EL - bending stiffness of the support pipe, kNm ² .