RU2315177C1 - Method and device for slot hole forming in casing pipe - Google Patents

Abstract

FIELD: oil and gas industry, particularly perforators and permeators.

SUBSTANCE: method involves creating slot in casing pipe wall, in cement ring outside the casing pipe and in productive bed by means of rotary cutting tool by serial cutting tool movement relatively casing pipe correspondingly in radial direction due to metered cutting tool advancing in vertical direction caused by perforator movement. Device comprises body with cutting unit arranged in the body, mechanisms for cutting unit driving and advancing and body support units. Cutting member is supported by axis of two parallel flat rocking-arms to provide cutting member rotation. Advancing mechanism comprises hydraulic cylinder with spring-loaded piston rigidly connected with rod and lever hinged to rod and to flat rocking-arm axis. Support members of the body include two body hydraulic cylinders with spring-loaded leg pistons and two pairs of support rollers. Each hydraulic cylinder and each pair of support rollers are arranged in upper and lower body parts correspondingly. Support rollers of each pair are located from cutting unit side and are equidistant one from another so that the support rollers are spaced predetermined angles from cutting unit plane. Hydraulic cylinders with leg pistons are arranged from opposite side thereof.

EFFECT: increased perforation capability.

2 cl, 3 dwg

Description

The invention relates to the oil industry, to the field of drilling and repair of oil and gas wells to create perforation channels in the casing, cement ring behind the casing and the reservoir.

The known method and device for slotted perforation of the casing of oil and gas wells (see RF patent No. 2254451, publ. 06/20/2005).

In this method of hydromechanical perforation, the formation of a gap in the casing wall is carried out cyclically by reciprocating the perforator, with the first part of the wall thickness of the casing being removed by cutting the casing wall with a planing tool, and hydromechanical rolling is carried out on the remainder of the thickness of the casing. Moreover, at each cycle of cutting the casing wall, the first step in the perforator increases the working pressure of the first calculated value, due to which the dosed supply of the planing tool is carried out in the direction of the casing wall. The second stage is the lifting of the punch to a predetermined height with the removal of part of the wall thickness of the casing equal to the value of the dosed feed of the planing tool. In the third stage, the puncher is lowered to its original position, and finally, in the fourth stage, the fluid pressure is released in the puncher for a short time to return the planer to its original position. Then the cycle is repeated.

A known device for hydromechanical slotted perforation of a casing string includes a housing with a longitudinal cutout in which a rolling tool is placed, a hydraulic cylinder with a spring-loaded hollow rod with a piston and a guide groove with a movable planing tool placed in it. In addition, a longitudinal cut-out and a hydraulic cylinder are made in the housing, in which a wedge pusher with a metering device for a planing tool and a spring-loaded piston with a rod are placed, at the end of which there is a stop element for interacting with the dividing mechanism of the planing tool.

The disadvantage of this method is that the proposed method for the formation of a gap in the wall of the casing with periodically repeated increases and depressurization of the medium, multi-cycle is time-consuming and thus economically impractical.

Closest to the described invention in technical essence is a downhole perforator (see patent No. 20057549, publ. 02.15.1994), which describes a method for perforating a casing string, including lowering the downhole perforator on the pipe string to the perforation site, creating pressure in the pipes, penetration of the casing wall, cement ring behind the casing and the reservoir by a rotating chain cutter having a metered feed to the side of the casing wall, the cutter returning to its original position after pressure relief Nia, moving the gun to a new place of perforation cutting to repeat the process.

The disadvantage of this method is that the perforation of the casing is carried out in separate sections with repetition of cycles. This method depends on large labor costs, which is also not economically feasible.

The purpose of the invention is to reduce the complexity of work on crevice, increase the reliability of the drill.

This is achieved in the proposed method, in which the formation of a gap in the wall of the casing, cement ring behind the casing and the reservoir by the rotating cutting tool is carried out by sequentially moving the latter respectively in the radial direction relative to the casing, while in the radial and vertical directions due to the metered feed of the cutting tool, and in the vertical direction - by moving the hammer in the same direction with the estimated speed of its feed at a given p state, for which a perforator with a hydraulic cylinder is used, the piston of which is connected mechanically with a rotating cutting tool and hydraulically with a working pressure cavity through hydraulic resistance, which serves for dosed supply of fluid into the piston cavity of the hydraulic cylinder, while the perforator has the ability to move vertically relative to the casing with the estimated speed of its feed at a given distance due to the wellhead lifting device.

To achieve the named technical result, a device is proposed for borehole slotted perforation of casing strings, which comprises a composite body with a cutting unit located therein, movably mounted on the body axis with the possibility of rotational-oscillatory motion and made in the form of flat rockers, chain transmission and kinematically connected with it rotating cutting element, drive and supply mechanisms of the cutting unit, housing support elements, rotating cutting tool is made in the form of disk mills , movably mounted on the axis of two parallel rockers with rotational motion, the feed mechanism comprises a hydraulic cylinder with a spring-loaded piston rigidly connected to the rod, and a lever pivotally connected at one end to the rod and the other with the axis of the plane rockers, supporting elements casings having the possibility of simultaneous interaction with the casing wall during perforator operation, consist of two housing hydraulic cylinders with spring-loaded pistons-paws and two pairs of supporting roles s, each movably placed on its axis of the housing, wherein the hydraulic cylinder and each pair of support rollers are located respectively in the upper and lower parts of the housing, the support rollers of each pair being located on the same side as the cutting unit and evenly spaced at predetermined angles from the plane of the cutting unit and hydraulic cylinders with piston paws are located on the opposite side.

Figure 1 shows a structural diagram of a device for downhole slotted perforation of casing strings; figure 2 is a cutting mechanism of a perforator along section AA; figure 3 - supporting elements along the cross section BB.

The device comprises a composite housing 1 connected to the lifting pipes 2, a cutting unit, drive and supply mechanisms of the cutting unit, and supporting elements of the housing. The cutting unit consists of a disk mill 3, mounted movably on the axis 4, two parallel-mounted rocker arms 5, which, in turn, are movably mounted on the axis 6 of the housing 1 with the possibility of rotational-vibrational motion and chain transmission 7, which serves to transmit rotational movements from the drive mechanism to the disk mill 3.

The drive mechanism consists of a hydraulic motor 8 installed in the housing 1, a gearbox 9, a gear gear 10 and a gear 11 of a chain gear 7, which is movably placed on the axis 6 of the housing 1.

The feed mechanism of the cutting unit consists of a hydraulic cylinder 12 with a spring-loaded piston 13, rigidly connected to the rod 14, and a lever 15, pivotally connected at one end to the rod 14 using the axis 16, and the other end - to the axis 4 of the rocker arm 5. The under-piston cavity of the hydraulic cylinder 12 has hydraulic communication with the working cavity 17 through the hydraulic resistance 18 using the channel 19.

The support elements consist of two hydraulic cylinders with spring-loaded pistons-paws 20 and two pairs of support rollers 21, each mounted movably on its axis 22. Each hydraulic cylinder and each pair of support rollers are located respectively in the lower and upper parts of the housing 1 (see Fig. 3, section B-B), while the support rollers of each pair are located on one side with the cutting unit and are equidistant in angle from the plane of location of the cutting unit, and the hydraulic cylinders with piston paws 20 are located on the opposite side.

The proposed device operates as follows. The device is lowered into the well on the lifting pipes 2 in a predetermined perforation zone. The working pressure of the liquid is created in the pipes, under the action of which the hydraulic motor 8 starts to work and through the gearbox 9, the bevel gear pair 10 and 11, the chain gear 7 rotates the disk mill 3. The pressure created in the pipes 2 above the hydraulic motor 8 is transmitted from the cavity 17 to the upper a hydraulic cylinder with a piston-paw 20 and through a hydraulic resistance 18 along the channel 19 of the lower hydraulic cylinder with a piston-paw 20 and a piston cavity of the hydraulic cylinder 12. In this case, the piston-paws 20 interact with the casing wall from one side to fi the perforator in the casing with the simultaneous interaction of the support rollers with the casing wall from the opposite side, and the piston 13 with the rod 14 of the hydraulic cylinder 12 by means of the lever 15 slowly moves the cutting unit with the disk cutter 3 towards the casing wall, while smoothly cutting into the wall casing string, cement ring behind the casing string and reservoir. Then, using a wellhead lifting device, the perforator is vertically moved with the calculated feed rate to a predetermined distance, while the rotating disk mill 3 continues the cutting process in the direction of movement of the perforator. After cutting, the pressure in the pipes is released. Under the action of the return springs, the piston 13 with the rod 14 of the hydraulic cylinder 12 and, accordingly, the cutting unit, the piston legs 20 return to their original position, thereby freeing the punch from fixing in the casing. After that, the device is raised to the surface.

Technical appraisal and economic advantages of the method:

reduced labor costs, increased reliability of the drill.

Information sources

1. RF patent No. 2254451, cl. ЕВВ 43/114.

2. RF patent No.2007549, cl. ЕВВ 43/114.

Claims (2)

1. The method of borehole slotted perforation of the casing string, including cutting the wall of the casing string, cement ring behind the casing string and the producing formation by a rotating cutting element having the possibility of dosed supply to the side of the casing string to form a gap, characterized in that a gap is formed in the casing wall , the cement ring behind the casing and the reservoir with a rotating cutting tool is carried out by sequential movement of the latter in the radial and in the vertical direction relative to the casing, in the radial direction due to the dosed feed of the cutting tool, and in the vertical direction by moving the punch in the same direction with the calculated feed rate at a given distance, for which a punch with a hydraulic cylinder, the piston of which is mechanically connected to a rotating cutting element and hydraulically with a working pressure cavity through a hydraulic resistance, which serves for dosed supply of fluid into the piston cavity hydraulic cylinder, while the hammer has the ability to move in the vertical direction relative to the casing with the estimated speed of its feed at a given distance due to the wellhead lifting device. 2. Device for borehole slotted perforation of the casing string, comprising a composite body with a cutting unit located therein, movably mounted on the axis of the body with the possibility of rotational-vibrational movement and made in the form of flat rockers, a chain gear and a kinematically connected rotating cutting element, mechanisms drive and feed the cutting unit, the supporting elements of the housing, characterized in that the rotating cutting element is made in the form of a disk cutter, movably mounted on the axis of two parallel to p flat rockers arranged with each other with the possibility of rotational movement, the feed mechanism comprises a hydraulic cylinder with a spring-loaded piston rigidly connected to the rod, and a lever pivotally connected at one end to the rod and the other with the axis of the flat rockers, supporting elements of the housing that can simultaneously interact with the casing wall during the operation of the punch, consist of two housing hydraulic cylinders with spring-loaded pistons-paws and two pairs of support rollers, each movably placed on its own axis a mustache, while each hydraulic cylinder and each pair of support rollers are located respectively in the upper and lower parts of the housing, and the support rollers of each pair are located on one side with the cutting unit and are evenly spaced from each other at predetermined angles from the plane of the cutting unit, and the hydraulic cylinders with claw pistons are located on the opposite side.

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