RU2069740C1 - Piercing perforator for formation of channels in casing strings of oil-gas wells - Google Patents

Abstract

FIELD: oil and gas production, particular, methods for perforation of oil and gas wells. SUBSTANCE: piercing perforator for formation of channels in casing strings of oil-gas wells has body with channel and air chamber. Body accommodate pressure amplifying unit made in form of cylinder which contains spring-loaded piston with rod. Spring-loaded piston has additional rod which forms hollow together with body. The hollow is communicated with air chamber. Body also accommodates working unit. The working unit is made in form of working cylinders hydraulically connected with pressure amplifying unit. Working cylinders accommodate working pistons with piercing devices. Piercing perforator also has the unit supplying working fluid to above-piston hollow. The unit supplying working fluid is made in form of reversible hydraulic pump with reversible electric motor. Above-piston hollow is hydraulically connected with hollow located under piston through channel and reversible hydraulic pump. EFFECT: higher operate reliability due to simplified design and installation of hydraulic pump with electric drive. 3 cl, 1 dwg

Description

 The invention relates to oil and gas production, and more particularly to a technique for perforating oil and gas wells by forming channels in a string and annulus to allow fluids to escape from the reservoir into the well.

There are various types of perforators for the formation of channels in the column, the main of which are cumulative and mechanical [1, 2]
Cumulative perforators form channels in the column with a blast wave, which is formed during the explosion of explosives. The disadvantage of these perforators is that the explosion destroys the cement stone behind the column and flows between the layers, as a result of which the productive layer is flooded, and its return is reduced or completely stopped.

 Mechanical perforators form channels in the column less dynamically, without impact, as a result of which the disadvantages of explosive perforation are eliminated. However, mechanical punchers have significant drawbacks. For example, a well-known piercing punch as an energy drive, we have powder bombs, which causes a one-time action of the punch and removing it after each puncture for reloading.

 These disadvantages are eliminated in the known mechanical piercing punch adopted for the prototype [3] The known piercing punch for forming channels in the casing strings of oil and gas wells contains a housing; the node of the pressure amplifier, placed in the housing and made in the form of a cylinder with a spring-loaded piston inside; a working unit placed in the housing and made in the form of working cylinders hydraulically connected to the pressure amplifier assembly, and working pistons in them with piercing tools, and a working fluid supply unit to the over-piston cavity. The working fluid is fed into the perforator under pressure, which ensures a multiple cycle of its operation. The liquid under pressure acts on the piston with the tool and moves it. The tool pierces the column. When the pressure is removed, the piston with the tool returns to its original position and is again ready for operation at the next pressure increase.

 The disadvantages of the prototype are: the complexity of the equipment for supplying the working fluid to the hammer; insufficient productivity due to the difficulties of moving the equipment for supplying working fluid; insufficient power of the punch; insufficient reliability of the drill due to the probability of jamming.

 This is achieved by the fact that in the proposed piercing punch for forming channels in the casing strings of oil and gas wells, the housing is made with a channel and an air chamber, and the spring-loaded piston with an additional rod forming a cavity associated with the air chamber with the housing. In this case, the node for supplying the working fluid to the supra-piston cavity is made in the form of a reversible hydraulic pump with a reversible electric motor, and the supra-piston cavity is hydraulically connected to the sub-piston cavity through the channel and the reversing hydraulic pump. The ratio of the cross-sectional area of the piston and its rods is in the range of 8: 1-20: 1. The supra-piston cavity is hydraulically connected to the sub-piston additional channel with a valve installed in it having a double electromagnetic and electric actuator.

 A positive effect in the proposed punch is achieved due to the following.

 Instead of a complex supply system from the unit through the pipes to the perforator of the working fluid, which must be displaced each time during the formation of the subsequent channel and disassembled at the mouth, a reversible electric motor with a hydraulic pump 5 is installed in the perforator.

 A small electric motor and hydraulic pump significantly reduced the dimensions of the perforator, made it mobile, quickly moving, lightweight, and therefore more productive.

 The choice of the ratio of the area of the piston and rods 8: 1-20: 1 provides an increase in the pressure of the working fluid by 8-20 times, increasing it to 2-3 thousand atmospheres, as a result of which the power and reliability of the drill increases.

 The installation of a double electromagnetic and electric valve actuator and the design of the parts increases the reliability of the valve and parts of the hammer drill in emergency situations.

 The proposed hammer drill is shown in the drawing, which shows the housing 1; reversible electric motor 2, reversible hydraulic pump 3, working cylinders 4, piston 5 mounted on pistons 5, piercing tools 6, cylinder 7 of a pressure amplifier, piston 8 of a pressure amplifier, spring 9 to return the piston 8 to its original position, cavity 10 above piston 8, cavity 11 under the piston 8, channel 12 connecting the hydraulic pump 3 to the cavity 10, channel 13 connecting the pump 3 to the cavity 11 under the piston 8, channel 14 connecting the cavity under the amplifier rod to the working cylinders 4, a closed chamber 15 without liquid, designed for lifting piston 8 the piston 5 to its initial position, the piston rod 16 16, acting through the channel 14 on the piston 5 by means of a working fluid, the piston rod 17, designed to equalize the volumes of the cavities 10 and 11 above and below the piston 8, which allows the cavities 10 and 11 to be performed alternately (when reversing the electric motor 2 and hydraulic pump 3) the role of the accumulator of the working fluid 18, connecting the cavity 10 and 11, designed to function in case of an accident, the valve 19 with a double actuator, an electromagnet 20, acting on the valve 19; geophysical cable 21, rod 22 for connecting the valve 19 with the geophysical cable 21.

 The punch works as follows.

 After turning on the electric motor 2, the hydraulic pump 3 delivers the working fluid into the cavity 10. By the action of the fluid pressure, the piston 8 moves downward, as a result of which the rod 16 displaces the working fluid through the channel 14 into the working cylinders 4. The fluid pressure in the cylinder 4 is so many times higher than the pressure in the cavity 10, how much the area of the rod 16 is less than the area of the piston 10 (minus the area of the rod 17). The piston 5 begins to move under the action of a liquid with high pressure.

 Tools 6, placed on the pistons 5, begin to be introduced into the column and annulus. The liquid from the cavity 11 is aspirated by the pump 3 along the channel 13. In this case, the cavity 10 plays the role of a storage device, since the cavities 10 and 11 are equal in volume.

 After the pistons 5 with the tools 6 are fully released, their movement stops, as a result of which the piston 8 with the rods 16 and 17 also stops. As a result of these stops, the fluid pressure in the cavity 10 increases as much as possible. The current consumption of the electric motor 2 also increases as much as possible. According to this indicator, the electric motor 2 is switched over, and the pump 3 starts pumping the working fluid out of the cavity 10 and pumps it into the cavity 11. The piston 8 starts to rise upward. The spring 9 and rarefied air in the chamber 15 also contribute to this (vacuum is created due to the movement of the rod 17 down). Moving the rod 16 together with the piston 8 upwards creates a vacuum in the cylinders 4, as a result of which the pistons 5 with tools 6 begin to move from the column to its original position. The pressure of the fluid located in the well under the static pressure of the fluid column also contributes to this. This fluid, acting on the tools 6 and pistons 5 from the side of the well, ensures the return of the piston 5 with the tool 6 to its original position.

 If the current is accidentally disconnected, the piston 5 with the tool 6 begins to move to its original position under the pressure of the well fluid. The rod 16 moves the piston 8 up. The working fluid flows from the cavity 10 through the pump 3, rotating it with a flow of passing fluid, and enters the cavity 11. After a fixed time, the piston 5 with the tool 6 will return to its original position. The hammer can be removed to the surface.

 In the event of a pump 3 accident, when it cannot rotate under the influence of a fluid flow and does not let it through, by turning on the electromagnet 20, the valve 19 is opened, and the working fluid flows from the cavity 10 into the cavity 11 through the channel 18.

 If the current is disconnected during the indicated accidents, then pulling the geophysical cable 21 (meaning that the knives 6 are in the column), act on the valve 19 with the help of a thrust 22 and tear it off, allowing the liquid to pass from the cavity 10 to the cavity 11.

 The spring 9 and the vacuum in the chamber 15 also contribute to the movement of the piston 8 up, and the piston 5 to its original position.

 Thus, five-variant punch protection is provided in case of an accident.

 Thus, the effective possibility of using a hydraulic pump driven by an electric motor with an increase in the working fluid pressure by a factor of ten with the simultaneous use of the volume of the amplifier as a fluid storage with the provision of a five-option reliable return of pistons with piercing tools to their original position with multiple safety against jamming of the punch was invented. in the well.

 The punch provides piercing of any number of channels in the string in one run into the well.

Claims (3)

 1. A piercing punch for forming channels in the casing strings of oil and gas wells, comprising a housing, a pressure amplifier assembly located in the housing and made in the form of a cylinder with a spring-loaded piston with a rod placed therein, a working assembly placed in the housing and made in the form of working cylinders, hydraulically connected to the node of the pressure amplifier, and working pistons in them with piercing tools, and a node for supplying working fluid to the supra-piston cavity, characterized in that the housing is made with a channel and an air chamber measure, and the spring-loaded piston is made with an additional rod forming a cavity associated with the air chamber with the housing, while the working fluid supply unit is made in the form of a reversible hydraulic pump with a reversible electric motor, and the supra-piston cavity is hydraulically connected to the piston cavity through the channel and the reversible hydraulic pump.  2. The hammer drill according to claim 1, characterized in that the ratio of the cross-sectional area of the piston and its rods is in the range of 8: 1 - 20: 1.  3. The hammer drill according to claims 1 and 2, characterized in that the supra-piston cavity is hydraulically connected to the sub-piston cavity by an additional channel with a valve installed in it having a double electromagnetic and electric actuator.