RU2302515C2 - Mechanical-hydraulic slit-type perforator - Google Patents

Abstract

FIELD: well drilling and operation, particularly perforators with extendable perforating members, for instance actuated by fluid means.

SUBSTANCE: perforator comprises body adapted to receive pushing piston, wedge and two levers. The pushing piston has central and two side hydraulic channels provided with hydraulic monitor heads. Each cutting tool is secured from one side of each lever. The cutting tools are spring-loaded from opposite sides thereof to urge tools one from another and may slide along wedge sides to project cutting tools in opposite directions. The perforator is provided with two guiding pads. Each guiding pad is carried by corresponding lever and connected thereto by means of additional pin to provide guiding pad projection in depressions as cutting tools are in projected state to cut through slots in production string. The depressions are formed in production string by means of cutting tools.

EFFECT: possibility to create two slits simultaneously in production string without cutting tool damage and jamming.

6 cl, 3 dwg

Description

The invention relates to the field of drilling and operation of wells, and in particular to a device for creating perforation slots in casing (operational) columns and inlet cavities.

The prior art devices for slotted perforation of casing strings based on the use of cutting tools in the form of cutters. Such a device is disclosed, for example, in RU 2070279, IPC 7 ЕВВ 43/114, 08.09.94, including a tubular housing with a reciprocating hydraulic cylinder, a piston of a hydraulic cylinder connected to a wedge pusher, a tool holder with perforating cutters , wedge pusher and return spring.

The disadvantages of this device are as follows:

firstly, the device is complex in design; secondly, it cannot be used in casing strings of small diameter, since due to its design features when manufacturing it in a reduced form, the length of the cutters exit is less than the thickness of the perforated pipe and cement stone behind the string, in addition, it does not develop forces sufficient for cutting perforation channels.

The closest analogue of the proposed device can be considered a hydromechanical borehole perforator according to the patent RU 2247226, IPC7 EV 43/112, 02.27.2005. The perforator contains a housing, a pusher-piston placed in it, equipped with a double wedge, with central and side hydraulic channels equipped with hydraulic nozzles, two retractable cutting disks mounted on the axles, each of the axes of the cutting disks mounted on the end of the corresponding rocker arm, articulated with a housing and mounted with the possibility of sliding on the sides of the double wedge of the piston-pusher and the extension of the cutting discs in opposite directions, while the free ends of the rocker arms are spring-loaded in towards each other.

The component parts of the device are easy to manufacture and easy to replace. However, when the gaps are formed in the production casing by the cutting unit of this device, there is a risk of jamming, because cutting tool cutting into one of the sides of the column wall occurs deeper than necessary due to the absence of restriction. In addition, the probability of cutting one gap in the casing earlier than the other leads to the clamping of the entire device to the cut side and eliminates the possibility of forming a diametrically located gap. In addition, during the hydromonitor treatment of cement stone and rock behind the column and in the cavity, the energy of the liquid stream decreases over a short distance, because there is the effect of a flooded stream, which does not allow to treat the bottom-hole zone of the formation sufficiently deep and efficiently.

The objective of the invention is to improve the mechanical properties of the hammer. The technical result, which provides the proposed invention, is to provide the possibility of forming a puncher simultaneously two longitudinal slots in the production casing without jamming the cutting tool and its breakage.

This technical result is achieved due to the fact that the hydromechanical slotted perforator containing a housing, a pusher-piston placed in it, made with a central and two side hydraulic channels equipped with hydraulic nozzles, a wedge and two levers with cutting tools fixed on one side of each of them, spring-loaded on the opposite side in the direction from each other and installed with the possibility of sliding on the sides of the wedge and the extension of the cutting tools in opposite directions, equipped wives with two guiding crackers, each of which is mounted on one lever using an additional axis with the possibility of extension with the retracted position of the cutting tools into the grooves formed in the production casing by cutting tools until the slots in the production casing are completely cut to allow symmetrical arrangement and fixation of the punch relative to the processed surface in the process of perforation, while the cutting tools are made in the form of cutters. In accordance with the first modification, the wedge is fixed at the end of the piston - pusher, and the levers are pivotally connected by axes to the housing. In accordance with the second modification, the wedge is mounted on the body, and the levers are pivotally connected by axes to the piston - pusher. Each lever has a surface made with the possibility of its abutment in the housing to limit the displacement of the perforator body from the axis of the column. The hydraulic nozzles of the perforator are made with an inner surface that ensures the twisting of the fluid emerging from it.

Figure 1 presents the first modification of the proposed device in its original position, and figure 2 is the same in the working position.

Figure 3 presents the second modification of the proposed device in the working position.

In accordance with the first modification, the perforator contains levers 2 mounted in the housing 1, pivotally mounted on it using the axles 3. The wedge 4 is made at the lower end of the piston - pusher 5. When the piston - pusher 5 is translationally moving along the axis of the puncher, it wedges between the levers 2, pushing them in different directions. The cutters 6 are fixed at one end of the levers 2, and the sockets 8 for the spring 9 are made at the other end, guide crackers 11 are mounted on the axes 10 there. The push rod 5 has a central flushing channel 12 and side channels 19 with hydraulic nozzles 18. In addition , figure 1 and 2 shows the processed production string 20.

In accordance with the second modification (figure 3), the levers 2 are pivotally mounted by the axes 3 to the piston - the pusher 5, and the wedge 4 is fixed in the housing 1.

The devices use jet nozzles with a swirling effect of the exit of the jet of working fluid (the same effect is present when the bullet leaves the rifled weapon).

The device operates as follows.

On the tubing string, the perforator is lowered into the well to the perforation site. Having installed the device in the well, a direct washing of the tubing pipe cavity from the scale is carried out. Then, a ball 15 is lowered into the pipe cavity, which, passing through the tubing suspension, the circulation valve and the hollow piston rod (not shown in the drawing), overlaps the central flushing channel 12 of the piston-pusher 5, after which the working pressure is created in the tubing.

In accordance with the first modification of the device, when creating a working pressure in the pipe cavity, the liquid acts on the plunger 5 with the wedge 4, moving it translationally along the axis of the device, the plunger 5 wedges between the levers 2 and spreads them on the axes 3 in opposite directions to the contact of the cutters 6, mounted on the levers 2, with the inner surface of the production casing 20. Then raise the perforator to the upper interval of perforation. Cutters 6 cut into the column to a predetermined depth, limited by the height of the cutters set from levers 2. After the cutters form grooves in the column, the fluid pressure in the tubing is released, and the piston-pusher 5 with wedge 4 is pulled back by the return spring located in the punch body to its original position , also the levers 2 are returned to their original position under the action of the spring 9, i.e. the cutters come out of contact with the column 20, and the guide crackers 11 remain in the grooves, preventing the perforator from changing the desired position. Then the punch is again lowered to the lower interval, and the cycle is repeated. The cycles are repeated until the slots in the production casing are completely cut. The surface A of the levers 2 serve as an emphasis on restricting the displacement of the punch body from the axis of the column 20 during slot cutting at the same time.

The operation of the device in accordance with the second modification occurs similarly, except that the extension of the levers 2 with the cutters 6 occurs due to their interaction with the wedge 4, mounted in the housing 1.

Thus, in the device according to the first modification, the levers are pivotally mounted on the body and do not translate together with the piston-pusher, but only rotate on the axes, and according to the second, the levers are pivotally mounted on the piston-pusher and move along it along the axis of the device.

The formation of slots is performed by moving the punch up to the length of the slit with two cutters mounted on the levers. After the formation of cracks in the production casing, the pressure in the pipe cavity is raised even higher and the jet monitor effect is realized. Two jets of liquid exiting through the proposed hydraulic nozzles 18 and twisting, destroy the cement stone and the rock behind it. After washing the caverns, the pressure in the pipes is reset to atmospheric.

The technical and economic advantages of the proposed hammer drill are as follows

1. Due to the implementation of the cutting unit with removable cutters that can be attached in any way, the time for their replacement is reduced, which is done through the grooves of the punch, excluding disassembling the entire device.

2. The selection of grooves by the cutters during the formation of cracks in the production casing takes place at a predetermined depth due to the ability to vary the height of the cutting surface of the cutters from the levers, which eliminates the risk of jamming of the punch during operation.

3. Through the use of hydraulic nozzles with the effect of twisting the jet of fluid, the bottom-hole zone of the formation is processed most efficiently.

4. Hydromonitoring treatment of the rock is carried out immediately after the formation of cracks, without requiring additional tripping operations, which saves time.

Claims (6)

1. A hydromechanical slotted puncher containing a housing, a pusher-piston located therein, made with a central and two side hydraulic channels equipped with hydraulic nozzles, a wedge and two levers with cutting tools fixed on one side of each of them, spring-loaded on the opposite side in the direction of each other from each other and installed with the possibility of sliding on the sides of the wedge and extending the cutting tools in opposite directions, characterized in that it is equipped with two guide crackers each of which is mounted on the corresponding lever with the help of an additional axis with the possibility of extension when the cutting tools are retracted into the grooves formed in the production casing by cutting tools until the slots in the production casing are completely cut. 2. The hammer drill according to claim 1, characterized in that the cutting tools are made in the form of cutters. 3. The hammer drill according to claim 1, characterized in that the wedge is mounted on the end of the piston-pusher, and the levers are pivotally connected by axes to the housing. 4. The hammer drill according to claim 1, characterized in that the wedge is mounted on the housing, and the levers are pivotally connected by axes to the piston-pusher. 5. The hammer drill according to claim 1, characterized in that each lever has a surface made with the possibility of its abutment in the housing to limit the displacement of the housing from the axis of the column. 6. A rotary hammer according to any one of claims 1 to 5, characterized in that the hydraulic nozzles are made with an inner surface that ensures twisting of the liquid leaving it.

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