RU2043486C1 - Device for well perforation - Google Patents

Abstract

FIELD: gas and oil producing industry. SUBSTANCE: device for well perforation includes body, piston and punch. Punch is rigidly connected with piston and has water course. Piston cross-section is in form of rectangle with rounded edges. Punch is made with recess on side surface that ensures communication between drill string-borehole annulus and drill string hollow in working position of device. Punch water course is made along its axis. EFFECT: improved performance characteristics due to reduced abrasion of punch and improved operating conditions of jet. 2 dwg

Description

 The invention relates to the oil and gas industry, in particular to hydromechanical perforators using a directional jet.

 Known perforator for drilling in oil and gas wells, forming a perforation hole in the wall of the casing with a knife fixed at one end to an axis in the perforator body and pushed out of the body by a piston with a nozzle located in it [1] The disadvantages of this perforator are the need to use a special pump equipment and compressor pipes designed for pressures above 200 MPa, as well as an inefficient knife loading scheme during the cutting process, bending and compression, which edopredelyaet its low reliability.

 A device for perforating wells containing a pressure multiplier and a housing with punches is known. The device allows you to pump fluid into the reservoir through the perforation through the bypass channel in the housing and the channel connected to it in the piston of the punch. The punches are returned to their initial position by a spring located under the piston of the pressure multiplier [2]. The device has the following disadvantages. The presence of a small diameter bypass channel for the passage of fluid injected into the formation leads to an increase in hydraulic resistance and pressure loss. The mechanical impurities contained in the injected fluid cause intense abrasive wear on the channel walls, making normal seal operation impossible. Punches used in the device, having the claimed form of channels for supplying fluid to the formation, are not able to form a fluid stream. The punch does not provide a channel for draining the spent liquid, which increases the pressure in the cavity and impairs the operation of the jet. In the proposed device, the actual punches after the puncture of the column remain in its body, providing only a one-time use of the device for descent. With rigid fastening of the punches to the pistons, a multiple use of the device for descent is achieved, however, the shape of the punches does not allow them to be returned to their original position by tensioning the tubing, which will cause an accident if the spring breaks under the multiplier piston. The device consists of a large number of parts, which reduces reliability.

 The invention is aimed at simplifying the design, increasing the reliability of the device, providing conditions for efficient operation of the jet.

 The essence of the invention lies in the fact that the device for perforating wells contains a housing, a piston and a punch with a flushing channel rigidly connected to the piston, the latter is made with a section in the form of a rectangle with rounded edges, and the punch with a groove on the side surface, with the possibility of annular space communication wells with its column space in the working position of the device, while the flushing channel of the punch is made along its axis.

 This is achieved by the fact that the piston is made in cross section in the form of a rectangle with rounded edges, which eliminates the pressure multiplier and the bypass channel for the fluid injected into the reservoir. The punch has a washing channel, made along its axis, forming an abrasive jet, and a groove on the side surface to divert it and reduce pressure in the annulus, which increases the efficiency of the jet and increases the length of the perforation channel.

 Figure 1 shows the proposed device of figure 1; figure 2 section along aa in figure 1.

 It contains a housing 1, a piston 2, a punch 3, having a flushing channel and a groove, a stroke limiter of the piston 4. The device is located in production casing 5.

 The device operates as follows. After lowering it to a predetermined depth on tubing, the pressure in the pipes is increased to 15.0 MPa. In this case, the piston 2 with the punch 3 comes out of the housing 1 and the production casing 5 is cut. Then, the formation rock is destroyed within 5-7 minutes by a liquid stream from the washing channel of the punch 3. The reflected stream with the rock particles is directed through the groove into the annulus. At the end of the perforation by lifting the tubing, the punch 3 and the piston 2 are returned to the device body 1. Then the process can be repeated.

 The use of this device allows to increase the efficiency of the perforation process by increasing the reliability and increasing the depth of the perforation channel.

Claims (1)

 A device for perforating wells, comprising a body, a piston and a punch with a flushing channel, rigidly connected to the piston, characterized in that the piston is made with a section in the form of a rectangle with rounded edges, and the punch is made with a groove on the lateral surface so that the annulus of the borehole can communicate with its column space in the working position of the device, while the flushing channel of the punch is made along its axis.

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