RU123064U1 - Borehole device for the implementation of rock fracturing - Google Patents

Abstract

A downhole device for hydraulic fracturing of rocks, including a body made in the form of a glass with holes in the wall for the passage of working fluid, dock seals with bushings installed on both sides of the glass, a spool installed in the glass and equipped with a spring pressing it to the bottom, a choke and a tip, characterized in that the body is equipped with a central tube having slotted slots at the bottom of the glass, the plunger-type spool is placed in the sealing sleeve and the spacer bushing holding it, the holes in the wall of the glass are oriented radially, in the sealing sleeve there are holes coaxial with the holes in the wall of the glass, and the spool, center tube, and packing sleeve are sealed to ensure tight connections.

Description

The alleged invention relates to mining, in particular, to controlling rock pressure by forced collapse of rocks and can be used to seal the zone of the initiating gap in the well during fluid or hydraulic fracturing of rocks.

A known device for hydraulic fracturing, including elastic shells mounted on hollow rods with radial and axial channels interconnected by a pipe, fixed external and internal sealing clips. The device is equipped with an adjustable pressure reducing valve installed between the shells, and the internal sealing rings are fixed to the rods by means of tapered bushings [1].

The disadvantage of this device is the low throughput of the pressure reducing valve, due to the presence in its design of locking elements (ball, spring), which impede the passage of the working fluid into the sealed space with the required performance. In this regard, the efficiency of the device is reduced. In addition, the use of a pressure reducing valve complicates the design of the sealing device.

The closest in technical essence and combination of features is a device for fracturing rocks in a well, adopted as a prototype, including a housing made in the form of a glass with holes for the passage of the working fluid, sealants with bushings installed on both sides of the glass, a spool installed in glass and equipped with a spring, pressing it to the bottom, fitting and tip [2].

The disadvantage of this device is the unreliability of the sealing pair, which includes a seal made of an elastic material and pressed against it by means of a spool spring, since with significant alternating efforts to press the spool against the seal (when closing and opening the device), there is a probability of destruction last one.

The technical task of the proposed solution is to increase the reliability of the explosive device due to the use of a slide valve, the design of which ensures effective tightness of the device with a sufficiently high durability of its operation.

This object is achieved in that in the downhole device for hydraulic fracturing of rocks, including a housing made in the form of a glass with holes in the wall for the passage of the working fluid, sealants with bushings mounted on both sides of the glass, a spool installed in the glass and equipped with a spring, pressing it to the bottom, the fitting and the tip, the housing is equipped with a central tube having slotted slots at the bottom of the glass, the plunger-type spool is placed in the sealing sleeve and holding its spacer sleeve ku, the holes in the glass wall are oriented radially, the holes are made in the sealing sleeve, are aligned with the holes in the glass wall, and the spool, the central tube and the sealing sleeve have seals that ensure tight joints.

The specified set of features can significantly improve the reliability of the device, since the use of a slide valve of the plunger type provides high-quality sealing with a sufficiently high durability of the device.

The essence of the proposed technical solution is illustrated by the description of the design of the downhole device for hydraulic fracturing of rocks and the drawing, which shows a longitudinal section thereof.

The downhole device for hydraulic fracturing of rocks consists of a hollow body made in the form of a glass 1 with openings 2 for the passage of the working fluid connected by the open part to the hollow sleeve 3 by means of a thread. In the bottom of the glass 1, a through central hole is made. At the ends of the housing (in the sleeve 3 and at the bottom of the glass 1), the sealants 4 and 5 (hereinafter sealing elements 4 and 5) are tightly fixed, which are able to deform under the action of the pressure of the working fluid. From the side of the free ends, the sealing elements 4, 5 are hermetically connected to the tip 6 and the fitting 7, respectively. In the cavity of the housing at the bottom of the cup, a sealing sleeve 9 is fixed by means of a spacer sleeve 8, in which a plunger-type spool 10 is placed, in the central opening of which there is a hollow pipe 11 installed between the bottom of the cup 1 and the end face of the recess in the sleeve 3. The walls of the sealing sleeve 9 have radial holes 12, the axes of which coincide with the axes of the holes 2 in the walls of the glass 1. The spool 10 is pressed against the end of the sealing sleeve 9 by a spring 13 installed between the spool 10 and the bottom of the sleeve 3. At the end of the of the whole pipe 11, slotted slots 14 are made from the bottom of the glass 1. Seals 15 in the sleeve 3, 16 in the spool 10 and 17 in the sealing sleeve 9 ensure the tightness of all connections of the device. The surface of the opening of the sealing sleeve 9 is ground on the outer diameter of the spool 10, which also provides sufficient tightness of the connection.

When controlling rock pressure by forced collapse of roof rocks, a downhole device for rock fracturing is located in a pre-drilled well with a cut initiating slot. Through the nozzle 7 serves the working fluid under pressure - the sealing elements 4 and 5, increasing in diameter, are pressed against the walls of the well, seal the section of the well on which the initiating gap is located. When the pressure exerted by the spring 13 is exceeded, the spool 10 starts moving towards the sleeve 3, thereby opening the access of the working fluid to the radial holes 12 and 2 in the walls of the sealing sleeve 9 and the cup 1 - the working fluid enters the sealed space of the well and produces a gap rocks. As a result of hydraulic fracturing, the pressure of the working fluid drops sharply, the spool 10 under the action of the spring 13 returns to its original position, and the sealing elements 4 and 5 take their original shape.

The use of a slide valve of the plunger type provides high-quality sealing of the movable joints of the device, which significantly increases the reliability and durability of the entire explosive device, that is, the achievement of the technical task.

Information sources

1. Device for hydraulic fracturing / a.s. USSR No. 877006, E21C 39/00, publ. 10/20/1981, bull. No. 40 (analogue);

2. A device for hydraulic fracturing of rocks in a well / RF patent No. 2367791, E21C 39/00, publ. 09/20/2009 (prototype).

Claims (1)

Downhole device for hydraulic fracturing of rocks, including a housing made in the form of a glass with holes in the wall for the passage of working fluid, sealants with sleeves mounted on both sides of the glass, a spool installed in the glass and equipped with a spring pressing it to the bottom, a fitting and a tip, characterized in that the casing is provided with a central tube having slotted slots at the bottom of the glass; glasses are oriented radially in grommet openings coaxial holes in the cup wall and the spool, the central tube and the sealing sleeve are of seal-tight connections.