RU2254451C1 - Method for hydromechanical slit perforation of casing column and device for realization of said method - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: method includes expanding of casing column using special tool with forming of a slit. According to invention firstly greater portion of casing column wall thickness is removed by cutting, and hydro-mechanical expansion is performed at remainder of thickness of casing string wall. For this perforator is used with hydraulic cylinder, piston of which is connected to expansion tool, and to additional hydraulic cylinder with scraping tool. Device has body, hydro-cylinder, spring-loaded hollow rod with piston, hydro-monitoring headpiece, expansion tool, supporting roller. According to invention guiding groove is made in the body, in which scraping tool is positioned. In the body recess is additionally made, in which wedge pusher and device for controlled feeding of scraper are positioned, which scraper is made in form of edge cam with dividing gear. Scraper tool is made with possible drive limiting. Hydro-cylinder is additionally made, wherein spring-loaded piston is placed, rod with stopping element, made for interaction with dividing gear. Sub-piston hollow of additional hydro-cylinder is hydraulically linked to working pressure hollow and to outer space.

EFFECT: higher precision.

2 cl, 2 dwg

Description

The invention relates to the oil and gas industry, in the field of drilling and repair of oil and gas wells to create perforations in the casing, cement stone and rock.

A device is known for slotted perforation of a casing string (see RF patent No. 2039220, publ. July 9, 1995), which describes a method for creating slotted channels, including lowering a hydromechanical perforator on a pipe string to the perforation site, creating pressure in the pipes and creating a gap by reciprocating perforator together with the movement of the piston system (piston-rod-piston) of the engine of the perforator with a hydraulic nozzle, while the formation of a gap is carried out by the force created by the pressure drop of the working fluid in the hydropore to the millet engine system and annulus, and the final formation of the slit of the perforation channel is carried out by the hydromonitor effect of the jet of working fluid with increasing pressure in the pipes after the cutting tool leaves the casing outside the casing string.

The disadvantage of this method is that for the formation of a gap in order to overcome the resistance of the material of the casing string, a large effort is required on the cutting tool - a rolled roller and, accordingly, a larger value in the pipes. This leads to emergency situations: jamming of the device, breakage of the cutting tool.

Closest to the described invention in technical essence is a device for slotted perforation of cased wells (see RF patent No. 2161697, publ. 10.01.2001), including the descent of the perforator on the pipe string to the place of perforation, the creation of a working pressure inside the column with simultaneous pacing layout and implementation of the indentation of the rolling roller into the wall of the casing.

The disadvantage of this method is that when a gap is formed on the roll roller, great efforts also arise. This leads to the need to apply a large operating pressure in the device, which makes it impossible to use the method of perforation of high-strength casing strings.

The purpose of the invention is to reduce the effort spent in the formation of a gap in the wall of the casing string, increase the reliability of the perforator and expand the possibility of using the method of slotted perforation of casing strings with higher strength characteristics.

This is achieved in the proposed method due to the reciprocating movement of the perforator with the formation of a gap in the wall of the casing string, first a large part of the wall thickness of the casing string is removed by cutting the wall of the casing string, and hydromechanical rolling is carried out on the remainder of the wall thickness of the casing string, for which a perforator with a hydraulic cylinder is used, the piston of which is connected with the rolling tool, and an additional hydraulic cylinder with a planing tool having the possibility of dosed supply for cutting casing the casing wall in cycles when the pressure rises to the first calculated value and the perforator rises, cut off this hydraulic cylinder when the pressure rises to the second calculated value to act on the piston of the rolling tool.

To achieve the above technical result, a device for hydromechanical slotted perforation of the casing is proposed, which comprises a housing with a longitudinal cut, a hydraulic cylinder, a spring-loaded hollow rod with a piston, a hydraulic nozzle, a rolling tool, a support roller, a guide groove in which the planing tool is placed with the possibility of reciprocating movement in the radial direction, optionally a longitudinal cutout in which the wedge pusher and the device are placed dosed feed of the planing tool, made in the form of an end cam with a dividing mechanism, movably placed on the axis of the housing, while the peripheral part of the end cam is located in the longitudinal cut of the planing tool with the possibility of their interaction to limit the progress of the planing tool in the direction of its feed into the cutting zone, additionally a hydraulic cylinder in which a spring-loaded piston is placed, a rod with a thrust element made at its end face for interaction with a divider mechanism the upper extreme position of the rod, while the wedge pusher with the lower end is rigidly fixed to the rod, and the upper end of the pusher, made with a slope relative to the axis of the device, is placed in a guide groove made with the same slope in the body of the planing tool, and the piston cavity of the additional hydraulic cylinder hydraulically connected to the working pressure cavity through the shut-off valve and to the external space through the throttle hole.

Figure 1 shows a device for hydromechanical slotted perforation of the casing in the initial position, figure 2 - in the working position, where the positions indicate the following: 1 - body; 2 - longitudinal cut; 3 - a hydraulic cylinder; 4 - hollow stock; 5 - the piston; 6 - hydraulic nozzle; 7 - rolling tool; 8 - a reference roller; 9 - guide groove of the planing tool; 10 - planing tool; 11 is a longitudinal section of a planing tool; 12 - an additional longitudinal cut; 13 - wedge pusher; 14 - end cam and 15 dividing mechanism of the metering device for feeding the planing tool; 16 - axis of the housing; 17 - an additional hydraulic cylinder; 18 - a piston and 19 - a rod of an additional hydraulic cylinder; 20 - persistent element; 21 - shutoff valve; 22 - throttle hole and 23 - channel for communicating the sub-piston cavity of the additional hydraulic cylinder, respectively, with the external space and with the working pressure cavity.

The proposed device operates as follows. The device is lowered into the well on tubing (tubing) in a given perforation zone. The working fluid pressure of the first calculated value is created in the tubing string, at which the piston 5 with the rod 4 moves the rolling tool 7 all the way into the casing, with the specified design force, as a result of which the housing 1 moves in the opposite direction until the support rollers 8 abut against the casing. At the same time, the fluid pressure is transmitted through a normally open shut-off valve 21 through a channel 23 to the under-piston cavity of the hydraulic cylinder 17. Overcoming the spring force, the piston 18 moves with the rod 19, the wedge pusher 13 and the stop element 20 until the latter interacts with the dividing mechanism 15. The dividing mechanism in turn, rotates around the axis 16 of the housing 1 to the end cam 14 to the first rear pitch angle, and the wedge pusher 13, interacting with the planing tool, carries out the first dosed under I feel it towards the cutting zone, while the feed dosage is limited by stopping the edge of the longitudinal cutout 11 of the planing tool in the profile of the end cam 14. Then, the tubing string is lifted to a height corresponding to the specified length of the slit in the casing wall, while the planing tool removes the first layer of material set value (depth of cut) of the main part of the casing wall thickness. After that, lower the device to its original position, relieve the pressure in the pipes for a short time. At this time, under the action of the spring, the piston 18, the rod 19, the wedge pusher 13 and, accordingly, the planing tool 10 are moved to their original position.

After the restoration of the fluid pressure in the pipes of the first calculated value, the piston 18, the rod 19, the wedge pusher 13 and the thrust element 20 are again moved until the latter interacts with the dividing mechanism 15. As a result, the end cam 14 switches again to the second predetermined dividing angle, and the cam profile increases , respectively, the supply of the planing tool in the direction of the cutting zone by applying a wedge pusher 13. When lifting the tubing string, the planing tool removes the second layer Container material a predetermined value (the cutting depth). Thus, the cycle is repeated until the main part of the wall thickness of the casing is completely removed. To remove the remaining wall thickness with the subsequent destruction of the cement stone in the tubing string, an increased liquid pressure of the second calculated value is created, at which the valve 21 closes, cutting off the piston cavity of the hydraulic cylinder 17 from the working pressure cavity. As a result, the pressure in the sub-piston cavity is released through the throttle hole 22 into the external space. Under the action of the return spring, the piston 18, the rod 19, the wedge pusher 13 and, accordingly, the planing tool 10 are moved to their original position. The increased working pressure created in the tubing string acts on the piston 5 of the hydraulic cylinder 3, and therefore, accordingly, an increased predetermined design force arises on the rolling tool 7 with which it acts on the casing and which is sufficient to force the remainder of the casing wall thickness columns, and then for the destruction of the annular cement stone. Through the reciprocating movement of the punch, the formation of a gap in the casing wall is completed.

When the rolling tool goes beyond the casing string, increased pressure is created in the tubing and the hydromonitor effect of the liquid stream flowing out of the nozzle 6 at a high speed, which, pouring cement stone and rock, forms a perforation channel.

To stop the operation, pumping of the working fluid is stopped. In this case, the pressure in the system drops and the spring force causes the piston 5 with the hollow rod 4 to return to its original position, removing the rolling tool 7 from the slot. The device will completely return to its original position. After that, the device is raised to the surface.

Technical appraisal and economic advantages of the method:

reducing the pressure in the tubing pipes, reducing the effort spent in the formation of a gap in the wall of the casing string, increasing the reliability of the perforator and expanding the applicability of the method of slotted perforation of casing strings with higher strength characteristics.

Sources of information

1. RF patent No. 2039220, cl. E 21 B 43/114.

2. RF patent No. 2161697, cl. E 21 B 43/114.

Claims (2)

1. The method of hydromechanical slotted perforation of the casing, including hydromechanical rolling of the casing with a rolling tool with the formation of a gap by reciprocating the punch, characterized in that first, most of the wall thickness of the casing is removed by cutting the wall of the casing, and hydromechanical rolling is carried out on the remainder of the thickness the casing walls, for which they use a hammer drill with a hydraulic cylinder, the piston of which is connected to the rolling tool, and add nym cylinder with planing tool having a dosing possibility to cut the casing wall cycles with increasing pressure to the first calculated value and raising the punch, the cut-off of the hydraulic cylinder when the pressure rises to the second calculated value for influencing the piston the Print Tool. 2. A device for hydromechanical slotted perforation of a casing string, comprising a housing with a longitudinal cutout, a hydraulic cylinder, a spring-loaded hollow rod with a piston, a hydraulic monitor nozzle, a rolling tool, a support roller, characterized in that a guide groove is made in the housing, in which the planing tool is placed with the possibility reciprocating movement in the radial direction, optionally - a longitudinal cutout in which the wedge pusher and the metering device of the planing tool are placed made in the form of an end cam with a dividing mechanism, movably placed on the axis of the housing, while the peripheral part of the end cam is located in the longitudinal cut of the planing tool with the possibility of their interaction to limit the progress of the planing tool in the direction of its feed into the cutting zone, in addition, a hydraulic cylinder, which placed a spring-loaded piston, a rod with a thrust element made on its end face for interaction with the dividing mechanism in the upper extreme position of the rod, while the new pusher with the lower end is rigidly fixed on the rod, and the upper end of the pusher, made with a slope relative to the axis of the device, is placed in a guide groove made with the same slope in the body of the planing tool, and the under-piston cavity of the additional hydraulic cylinder is hydraulically connected to the working pressure cavity through shut-off valve and with external space through the throttle bore.

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