RU2470136C1 - Locking device for well equipped run in on string - Google Patents

Abstract

FIELD: oil-and-gas industry.

SUBSTANCE: invention relates to oil and gas production, particularly, to devices intended for locking external tooling on string run in the well. Proposed device comprises ring-like bush with inner grooves to receive appropriate locking element composed of one-sided wedge with locking triangular ledges facing the pipe, perpendicular to its axis. Said bush is rigidly coupled with well equipment while said grooves are arranged in lengthwise direction of said bush and regularly spaced apart in circle with inclined surface complying with wedge angle and directed downward, toward bush axis. The number of said wedges equal that of grooves. Wedge bottom has elastostrained stem with retainer on outer side. Annular grooves to receive wedge retainer are made at bush, right under said grooves.

EFFECT: higher reliability.

2 dwg

Description

The invention relates to the oil and gas industry, in particular to devices for securing the technical equipment of external equipment on a pipe string, lowered into the well.

A known locking element for securing the centralizers to the casing string (see the governing document of Tatneft JSC, RD 39-0147585-152-97, effective from 01.01.98), which is a bolt with a pointed end, screwed into the hole with a threaded thread in the locking sleeve or the sleeve part of the equipment lowered into the well.

Known locking device for downhole equipment, lowered on a pipe string (see the same source - RD 39 0147535-152-97 JSC "Tatneft"), containing a sleeve in the form of a ring with an inner ring groove and radial holes for entering into the groove, after installation rings on the pipe of the column, twisted locking element with fixing ribs made on it.

The closest in technical essence is the locking device for downhole equipment, lowered on a pipe string (see RF Patent No. 2190079, IPC 7 Е21В 19/00, 17/10, publ. In Bulletin No. 27, 09/27/2002), comprising a sleeve in the form of a ring with an internal annular groove and radial holes for introducing into the groove a locking element with fixing ribs made on it, while the housing of the locking element is made in the form of a one-sided wedge, and its fixing ribs are in the form of grooves and protrusions having a section triangular shape made in the longitudinal direction from the side of the inclined plane, while the locking element is made of flexible metal with fixing ribs in hardness greater than the material of the pipes.

A common disadvantage for analogues is the insufficient reliability of fixing technological equipment at high alternating loads, since the fixing ribs have a limited mating surface with the pipe body and a limited radial contact force with the outer surface of the casing, as a result of which emergency situations associated with displacement from the installation site are encountered fixed equipment during the descent of the pipe string into the well.

The technical task of the present invention is to increase the reliability of the locking device by increasing the stragging force of the fixed equipment, resulting in the elimination of emergency situations

The suppressed technical problem is solved by the described locking device containing a sleeve in the form of a ring with internal grooves for the corresponding locking element, made in the form of a one-sided wedge with fixing triangular protrusions facing the pipe perpendicular to its axis.

What is new is that the coupling is rigidly connected to the downhole equipment, and the grooves are made longitudinally to the coupling axis uniformly around the circumference with an inclined surface corresponding to the angle of the wedges, the number of which is equal to the number of grooves, and directed downward towards the coupling axis, while the wedge is equipped with an elastically deformable shaft with a lock on the outside, and the coupling below the grooves is equipped with annular grooves under the wedge lock.

The drawings illustrate the essence of the invention, in which Fig. 1 shows a locking wedge mounted on a pipe with fixed downhole equipment in section.

Figure 2 is a section along aa of figure 1, which shows the equipment mounted on the pipe with locking wedges.

The inventive locking device comprises a locking one-sided wedge 1 (see Fig. 1) made of tool steel, in hardness greater than the material of the pipe 2 on which the technological equipment is fixed (centralizers, turbulators, etc., in Fig. 1 and 2 not shown). On the vertical plane of the wedge 1, transverse fixing protrusions 3 are made in the form of linear grooves and protrusions having a triangular shape in cross section. On the outside, the wedge 1 is equipped with a resiliently deformable shank 4 with a retainer 5 at the bottom. The coupling 6 is rigidly connected to the downhole equipment (not shown in Figs. 1 and 2). On the inner surface of the coupling longitudinally along its axis and evenly circumferentially, guide grooves 7 (FIG. 2) are made with an inclined surface 8 (FIG. 1) corresponding to the angle of the wedges 1 and annular grooves 9 under the retainer 5 of the wedge 1.

The locking device operates as follows.

To fix equipment (not shown) connected rigidly to the sleeve 6 on the pipe string 2, the wedges 1 are inserted by force of hand into the longitudinal guide grooves 7 (FIG. 2) of the sleeve 6 between the pipe 2 and the sleeve 6, while the transverse locking tabs 3 (FIG. .1) the wedge 1 is directed to the pipe 2. Then, shifting the equipment along the pipe upward with blows from below, they achieve the recession of the retainer 5 of the wedge 1 into the annular grooves 9 until characteristic clicks occur. At the same time, the clamps prevent the locking wedges from falling out of the annular grooves, ensuring reliable fixation of the equipment on the pipe string during hoisting operations.

This method of fixing the equipment prevents sliding of the locking protrusions 3 of the one-way locking element 1 on the surface of the column 2, prevents wear of the sharp edges of the protrusions 3 and retains their fixing ability.

In the process of lowering the string of pipes 2 into the well due to friction against the walls of the well (not shown in FIGS. 1 and 2), the downhole equipment (string equipment) mounted on the pipes is subjected to axial shear and is partially shifted relative to the retaining wedges fixed on the outer wall pipe columns 2. As a result, the forces pressing the locking wedges 1 against the wall of the pipe string 2, and therefore the axial load maintained by the locking device as a whole, increase due to the effect of self-jamming, which eliminates the need for iynye situation.

The proposed design of the locking device allows to increase the reliability of fixing the equipment to the pipe string being lowered into the well, which ensures its accurate installation in a given interval of the well and avoids emergency situations.

Claims (1)

A locking device for downhole equipment, lowered onto a pipe string, containing a sleeve in the form of a ring with internal grooves for the corresponding locking element, made in the form of a one-sided wedge with fixing triangular protrusions facing the pipe perpendicular to its axis, characterized in that the sleeve is rigidly connected to the downhole equipment, and the grooves are made longitudinally to the axis of the coupling uniformly around the circumference with an inclined surface corresponding to the angle of the wedges, the number of which is equal to the number of grooves, and lower to the side of the coupling axis, while the wedge is equipped with an elasto-deformable shank from the bottom with a lock on the outside, and the coupling below the grooves is equipped with annular grooves for the wedge lock.

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