RU2751046C1 - Hydromechanical slit puncher - Google Patents

Abstract

FIELD:

SUBSTANCE: invention relates to a device for secondary opening of formations by creating longitudinal slots in the casing (production) strings and the formation of filtration channels in the bottomhole formation zone. The objective of the invention is to eliminate the phenomenon of non-simultaneous slotting, to improve the reliability of tracking according to the readings of the weight indicator device when perforating the columns. The task is achieved due to the fact that in a hydromechanical slotted perforator containing a housing, a pusher piston placed in it, a cutting mechanism in the form of a knurling disk mounted on the axis with a mechanism for its extension, two jet nozzles, hydraulically communicated by means of channels with overpiston cavities of the housing, spring, as part of the mechanism for the return movement of the discs to the initial position, according to the proposed solution, the piston with the rod, when moving, pushes down the stop with the bracket and the associated mechanism for extending the rolling disks, made in the form of two rack and pinion pushers, which, by means of gearing, rotate four gears sitting on two spline axes, and in turn rotate two lever with knurled discs until it touches the pipe walls.

EFFECT: simultaneous cutting of slots in the walls of the column when using a rack-and-pinion mechanism for extending knurled disks sitting on two different levers and working in the perforation process under equal conditions.

1 cl, 1 dwg

Description

The invention relates to a device for secondary opening of formations by creating longitudinal slots in the casing (production) strings and the formation of filtration channels in the bottomhole formation zone.

From the prior art known double-disc slot perforators with the placement of rolling discs on a two-arm rocker arm (No. 2546687 E21B 43/112, publ. 2005). The extension of the disks for the perforation of the column is carried out by turning the rocker arm due to the creation of excess pressure in the above-piston area. The piston moves down and moves the wedge guides through the rod, which press on the upper arm of the rocker arm and rotate it around the central axis until the knurled discs (at two diametrically opposite points) touch the inner surface of the perforated column. Further, the slots are cut by a stepwise increase in pressure and a step-out of the assembly by the value of the perforation interval along the column axis.

The disadvantage of the device is that when testing this design of the perforator on a special stand for cutting slots in the casing, it was found that the discs do not cut through the pipe walls at the same time. The disc located on the upper arm of the rocker arm and supported on the guides of the wedge fork cuts through the pipe wall earlier than the disc on the unsupported lower arm. This is due to the elastic deformation of the rocker arm from the reactive forces acting on the discs in the process of cutting the slots. This phenomenon creates great inconvenience for tracking the complete cutting of two diametrically opposite slots.

Known perforator hydromechanical slotted (adopted as a prototype, US Pat. RF No. 2327859 E21B 43/112, publ. 2008), containing a housing, placed in it a piston-pusher and a retractable cutting tool in the form of upper and lower cutting discs, each of which installed on its axis, the mechanism for their advancement in the form of a rocker arm mounted on the central axis, in the arms of which the axes of the cutting discs are installed and made with the possibility of rotation when moving the piston-pusher.

The disadvantage of the perforator is the non-simultaneous cutting of the slots in the walls of the casing by the discs.

The objective of the invention is to eliminate the phenomenon of non-simultaneous cutting of slots, to increase the reliability of tracking according to the readings of the GIV instrument when perforating the columns.

The technical result consists in the simultaneous cutting of slots in the walls of the column when using a rack-and-pinion mechanism for extending the rolling disks sitting on two different levers and working in the perforation process under equal conditions.

The task is achieved due to the fact that in a hydromechanical slotted perforator containing a housing, a pusher piston placed in it, a cutting mechanism in the form of a knurling disk mounted on the axis with a mechanism for its extension, two hydromonitor nozzles, hydraulically communicated by means of channels with overpiston cavities of the housing, the spring, as part of the mechanism for the return movement of the disks to the initial position, according to the proposed solution, the piston with the rod, when moving, pushes down the stop with the bracket and the associated mechanism for extending the knurled disks, made in the form of two rack and pinion pushers, which, by means of gearing, rotate four gears, sitting on two spline axles, and in turn turn two levers with knurled discs until they come into contact with the pipe walls.

The design of the proposed perforator is shown in figure 1, where the positions indicate: 1 - nozzle, 2 - rack pusher, 3 - body, 4 - cylinder, 5 - retainer, 6 - liner, 7 - slotted axis, 8 - knurled disk, 9 - axis , 10 - washer, 11 - lever, 12 - saddle, 13 - stop, 14 - bracket, 15 - pin, 16 - nut, 17 - rod, 18 - spring, 19 - piston, 20 - screw, 21 - bushing, 22 - plug, 23 - gear, 24 - housing cover, 25 - guide plate, 26 - ball.

The principle of the hammer drill is as follows. Having installed the perforator at the desired level of perforation, create a working pressure inside the assembly, move the assembly up and down within a predetermined interval (length of the cut slots). In this case, the piston 19 moves down and through the rod 17 moves down the stop 13 with the bracket 14 and the two rack and pinion pushers 2 associated with them inside the groove of the housing 3, which, by means of gearing, rotate four gears 23 sitting on two spline axles 7, which in turn turn two levers 11 with knurled disks 8 until they come into contact with the pipe walls. When the pressure is subsequently increased and the assembly moves within a predetermined perforation interval, the rolling disks 8 are pressed into the walls of the casing.

When the rolling disks 8 go beyond the casing wall (determined by the jump in the GIV instrument readings), an increased pressure is created inside the assembly and the jetting effect is realized. The jets of the working fluid flowing out of the two nozzles-nozzles 1 at a high speed erode cement stone and rocks and form a perforation channel.

To terminate the operation, the pumping of the working fluid is stopped. At the same time, the pressure in the system drops and the force of the spring 18 the piston 19 with the hollow rod 17, the stop 13, the bracket 14 and the rack and pinion pushers 2 turn the gears 23 with the lever 11 to their original position, removing the knurled disks 8 from the cut slots. The hammer drill goes into transport position, after which it is lifted to the surface.

Claims (1)

A hydromechanical slotted perforator containing a housing, a pusher piston placed in it, a cutting mechanism in the form of rolling disks mounted on the axes with a mechanism for their extension, two hydromonitor nozzles, hydraulically communicated by means of channels with above-piston cavities of the housing, a spring as part of the mechanism for returning the disks to the initial position, characterized in that the piston with the rod is made with the ability, when moving them, to move down the stop with the bracket and the associated mechanism for extending the rolling disks, made in the form of two rack pushers installed inside the housing groove, which, by means of gearing, ensure the rotation of those sitting on two spline axles of four gears, which in turn provide rotation of two levers with knurled discs until they come into contact with the pipe walls.

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