SU1049647A1 - Multistage drilling tool - Google Patents

Description

four; with

O) 4 1

The invention relates to a drilling technique and can be used for simultaneously curving and drilling wells in anisotropic rocks.

A stepped drilling rig is known, including a calibrator mounted above the reamer and a centering element mounted between the latter and the bit on the leading part fl}

The disadvantage of the design lies in the fact that the rigid fixing of the advance part of the projectile with the expander restricts the set of eccentricity of the axes of the pilot bore and the expanded borehole and does not significantly affect the intensity of the curvature of the boreholes. In addition, at the junction of the advance part of the projectile with the expander, cyclic loads occur during drilling, which cause the projectile to break and limit the axial load on the bit, and installing the support-centering element directly above the bit does not allow to combine the optimal axial load on the bit with the optimum for this part of the well moment. Deviating chisel. In the direction opposite to the natural curvature ... The closest technical solution to the proposed is a stepped drill bit containing an advance part with a bit connected by a hinged coupling with an expander of the main string 2.

The disadvantage of this screen is. that it works on the principle of a plumb line, and therefore it is possible to carry out the curvature of a well only by a few flights, which is unproductive.

The purpose of the invention is to provide directional drilling of a well. the side opposite to its natural curvature, with simultaneous expansion of the well.

This goal is achieved by the fact that a stepped drilling projectile containing a leading part with a bit connected by a hinged coupling to an expander of the main column is equipped with a caliper JYr placed above the expander, and the support-centering element installed between the bit and the hinge coupling is located from the bit at a distance, equal to 0.1-0.3 length of the advanced part of the projectile.

The drawing shows a stepped drill hole, a general view.

The stepped drilling rig contains a calibrator 1, mounted above the expander 2, a support-centering element 3, mounted. Between it and a chisel 4, and a hinged coupling 5,

the connecting leading part 6 of the projectile with the expander with the possibility of torque transmission. In this case, the working surfaces 7 of the centering element 3 are barrel-shaped. The support-centering element 3 is fixed on the leading part of the projectile at a distance (from the bit 4 equal to 0.1-0.3 of its length, and the length of the leading part is 10-20 bit diameters.

The lower limit of the ratio of sizes for mounting the support-centering element 3 on the advanced part of the projectile is selected experimentally, based on the actual height of the bits used, i.e. as close as possible to the centering element to the face, which improves the conditions of bit operation and corresponds to the minimum intensity of the curvature of the well for a given length 2.

The upper limit of the specified ratio is limited to the actually existing values of the deflecting forces that occur on expander 2 and bit 4, and is adjusted so that when the strength of the drilled rock is increased by 2-3 times, the lateral force on the bit does not deflect the extender in the direction opposite to the natural eccentricity extensions.

The limits of the length of the advance part 6 of the projectile are chosen on the basis of the condition that the rigid body is retained from side to side and that the required angles of deflection are provided in the leading trunk. wells with the aim of the most rational use of the effect of eccentric expansion (EER b

The stepped drilling rig operates as follows ..

While simultaneously drilling ahead of the trunk and expanding it, gold 4 and expander 2 tend to shift due to the anisotropy of the rocks towards their best drillability, i.e. in the direction of natural curvature. The offset, about the center of the annular ledge produced by the expander 2, is stabilized by the calibrator 1 with respect to the axis of the leading barrel, and the top of the leading part 6 is rotated in an 11-hinge coupling 5 at an angle oL relative to the centering element 3, shifting the bit 4 in the opposite direction. Thus, by changing the line 2 of the advanced part b and growing P from the centering element 3 to the bit 4, the intensity of the curvature of the well in the plane of its natural curvature can be changed by changing the angle oL and the bias force acting on the bit 4. This eliminates the possibility of plane parallel displacement

In the borehole of the bit and the expander, it allows to fully use the EER for changing the zenith angle of the well, providing the latter in the direction opposite to its natural curvature. At the same time, the projectile allows the well to be curved at an optimal axial load on the bit.

The technical and economic efficiency of the invention is to reduce the time and material costs of positioning the directional well.

Claims (1)

(54'1 (57) STEPPED “DRILLING EQUIPMENT, ·] containing an advanced part with a chisel connected by an articulated sleeve to an extender of the main string, characterized in that, in order to provide directional drilling of the well in the direction opposite to its natural curvature, with simultaneous · extension borehole, it is provided with a spreader located above the calibrator and mounted between the bit and socket hinge supporting-alignment element, the latter being located on the bit a distance equal to the length of advance of 0.1-0.3 parts projectile _β A. © SU.1049647