SU1696661A1 - Turbodrill - Google Patents

Abstract

The invention relates to the drilling of wells and improves the efficiency when drilling the second bore by increasing the angle of deviation of the axis of the bit (D) from the axis of the borehole while maintaining the strength of the threaded connections of the casing (K), reducing wear D during tripping; to control the control of the second barrel. The turbo-drill contains K 1 with shaft 3 installed in it by means of angular contact bearings 2. A support element 5 is mounted on K 1. Axes of shaft 3 and inner cylindrical surface (CPU) 7 K 1 are inclined at an acute angle of / 5 to the axis of its external CPU 8 The 10 K 1 string of drill pipes is connected by means of the sub 9. The material of the latter has a modulus of elasticity less than that of the case material 1 and the drill string of the string 10. The threaded joint axis of the sub 9 with K 1 is inclined at an acute angle to the axis of the external CPU 8 in the apsidal plane tour beaver. Working bodies 6 of the latter were made in the form of propeller turbines. During the descent of the turbo-drill into the borehole, because the sub 9 has a large deformation capacity, the magnitude of the force pressing D 4 to the borehole wall is limited. As a result, the wear of the D 4 elements is reduced when finishing it at the cutting point. 3 hp ff, 1 ill. cl

Description

The invention relates to the field of drilling wells and can be used when drilling a second wellbore.

The aim of the invention is to increase the efficiency when drilling the second bore by increasing the angle of deviation of the axis of the bit from the axis of the borehole while maintaining the strength of the threaded connections of the body, reducing the wear of the bit during lowering and lifting operations of the second bore.

The drawing shows a turbo-drill, a longitudinal section.

The turbodrill comprises a housing 1 and a shaft 3 mounted with a radial-thrust bearing 2 with a chisel 4. A supporting element 5 is installed on the upper part of the housing 1 in its apsidal plane. The distance from the edge of the supporting element 5 to the contact of the housing 1 with the wall wells do not exceed the diameter of the bit 4. The working bodies of the 6 turbodrill are made in the form of propeller turbines. The axis of the shaft 3 and the inner cylindrical surface 7 of the housing 1 is inclined at an acute angle of the axis of the outer cylindrical surface 8

oh oh oh

Os

housing 1, This angle is determined from the expression

tfl / J 2iXlpX2l

where Xi is the maximum thickness of the body;

X2 - the thickness of the case is minimal;

I is the distance between the upper and lower radial bearings of the turbo-drill shaft.

The angle of inclination of the shaft to the axis of the well + / J, where ct is the angle of inclination of the body of the mowing hole, determined from the expression

„A-uft where Od is the diameter of the bit;

From - diameter of the turbo-drill;

L is the distance from the point of contact of the top point of the turbo-drill with the borehole wall to the lower edge of the bit.

Translator 9 connects body 1 to a string of drill pipes 10. The threaded joint axis of the sub 9 with body 1 is inclined at an acute angle y to the axis of surface 8 in the apsidal plane of the turbo-drill for slightly pressing bit 4 to the borehole wall. The magnitude of the elastic modulus of the material of the sub 9, made, for example, of duralumin, is less than the magnitude of the elastic modulus of the materials of the housing 1 and the drill pipe string 10, made of steel.

To ensure that the second barrel is cut, especially in hard rock, the deflecting force tends to get as large as possible. In addition, in order to facilitate and intensify the kickoff, the arrangement is performed such that the angle between the axis of the bit and the well is as large as possible. The use of large deflection forces in arrangements is limited, on the one hand, by the difficulty of advancing the assembly in the wellbore, and, on the other hand, by the difficulty of starting a turbo-drill due to the large torques arising on the bit.

The specific moments during the cutting multiply exceed the specific moments during normal drilling.

During the descent of the turbo-drill into the well due to the fact that the sub 9 has a large deformation capacity, the amount of force that presses the bit 4 to the wall of the well is limited. As a result, the wear of the working elements of the bit 4 is reduced while finishing it to the place of cutting. The limitation of the force pressing the bit to the wall of the wells during the drilling process, and an increase in the rotation frequency are necessary for a number of reasons:

reduction of the deflection of the housing 1, negatively affecting the cutting process, as the deflection of the housing 1 reduces the angle between the axis of the bit 4 and the axis of the well;

a reduction in the required torque value at bit 4, which allows for drilling at high revs;

a decrease in the amplitude of the torsional vibrations of the bottom of the drill string, which negatively influences the cutting process;

the ability to operate a turbo-drill in modes close to overclocking, since the cutting of the second bore is a process of milling the borehole wall, to which

5 shows a high-speed operation mode;

proportional to the square of the rotational frequency, the kinetic energy of the rotating mass increases, which to a greater extent absorbs the peaks of the moments appearing on bit 4, and therefore reduces the amplitude of torsional vibrations, which, in turn, to a greater degree ensures continuous contact of bit 4 with the borehole wall in given point;

5, the improvement of the launch of the turbo-drill, since the specific moment from the deflecting force is much greater than from the axial load.

In order to control the process of cutting the second barrel and the mode of operation of the turbo-drill, the successive sets are equipped with propeller turbines, in which the rising pressure line from idle to brake.

In high-speed mode, the second bore is recommended for

5 to use either diamond drill bits or non-supporting bits from Slavutich type ISM.

Claims (4)

1.Turbobur, comprising a housing with a shaft mounted through radially resistant bearings, working members and a supporting element mounted on the housing, characterized in that, in order to increase efficiency when blocking the second barrel by increasing the angle of deviation of the axis of the bit from the axis of the well while maintaining the strength of the threaded connections of the housing, the shaft axis and the inner cylindrical surface of the housing are inclined at an acute angle to the axis of the outer cylindrical surface of the housing. 2.Turbobur according to claim 1, characterized in that, in order to reduce bit wear during tripping, the material of the sub connecting the case to the drill pipe has a modulus of elasticity less than that of the case material and drill string. pipes. 3.Turbobur according to claim 1, characterized in that, in order to control the second barrel cutting, the working bodies are made in the form of propeller turbines, 4. A turbo-drill according to claim 1, characterized in that the axis of the threaded joint of the sub with the body is inclined at an acute angle to the axis of the outer cylindrical surface of the body in the apsidal plane of the turbo-drill. - / J