RU73030U1 - DEVICE FOR HYDRODYNAMIC IMPACT ON THE BOTTOM ZONE - Google Patents

Abstract

The utility model relates to devices for developing a deep well and is intended to create periodic pressure in the bottomhole zone to increase the flow of fluid from the formation into the well by increasing the efficiency of hydraulic fracturing. The objective of the utility model is to create a device for processing the bottom-hole zone of the well to increase the efficiency of hydraulic fracturing of deep wells, increase the flow of fluid from the formation into the well and oil recovery to increase technical and economic indicators. This object is achieved in that the device for creating pressure in the bottomhole zone including the casing with holes, the layout of the liner with holes, packer, anchor, pipes, characterized in that the new one is that a centralizer and an inner cylinder are installed above the armature and piston an external piston with a check valve inside, the piston has minimal gaps with the walls of the casing and is connected to the pipe string, the weight of which when the pipes move downward creates a pressure greater than the fracture pressure fins, and ground-based pumping units are equipped with bypass valves that open when the column moves down and closes the check valve.

Description

The utility model relates to the stage of well development, is intended to create high pressure in the bottom hole zone, and more particularly to devices for hydrodynamic effects on the bottom hole zone of the well.

A device for processing the bottom-hole zone of a well by implosion method (USSR Author's Certificate No. 1004624, M. Cl. ³ ЕВВ 43/26, 1983), consisting of a housing with radial channels, a thrust shoulder and a partition, a lower step piston with a limiter and an axial channel, the upper spring-loaded piston with an axial channel, a spring and a ball valve mounted between the pistons. The device is installed in a tubing string and is equipped with a packer.

The device operates by pumping formation fluid from the well, creating a "well-formation" differential pressure, under the influence of the formation water flow coming from the well and using the formation energy. In this case, the drainage channels are cleaned and permeability increases, however, with a further decrease in reservoir pressure under the influence of rock pressure, skeleton strength will be violated, pores, cracks will close and permeability will decrease.

The closest in technical essence to the claimed utility model is a device for hydrodynamic impact on the bottomhole zone of the well, comprising a housing, an injection and discharge chamber separated from each other by a locking element made in the form of a piston equipped with a check valve. Utility Model No. 19866 RU Cl. 7 Е21В 43/26, 28/00 dated 10/10/2001 Bull. No. 28).

The disadvantage of this device is its complexity and the presence of a downhole jet pump, the operation of which is carried out through the use of high pressure units, for example 4AN-700. They develop a pressure of up to 700 kg / cm ² , which provides hydraulic fracturing at the maximum possible depth H = P _p /0.25...0.15=700/0.25=2800...4667 m. And this eliminates the possibility of effective use of the device for the development of hard-to-recover reserves at depths of more than 4667 m. Tubing, fittings and manifold are subjected to high pressure, with the possibility of hydraulic shock and destruction of equipment. The maximum possible internal pressure of tubing for strength groups L and M should not exceed 50 MPa (500 kG / cm ² ), which also technically limits the possibility of using the device. The need to create high pressure and constant drive power limits the performance of the pumps and leads to the need to increase the number of units, increase the cost, increase complexity and reduce safety. In addition, it is necessary to create cyclic pressure, which would provide fatigue cracking of the rock, deepening and expansion of cracks, and high-amplitude wave action.

The problem solved by the utility model is the creation of a downhole device for hydrodynamic impact on the bottomhole zone to increase the efficiency of hydraulic fracturing at great depths and to intensify the flow of fluid from the formation into the well.

The technical result is the creation of a source of higher cyclic, pulsating pressure in the bottomhole formation zone, ensuring hydraulic fracturing and increasing the permeability of the formation at great depths, limiting the internal pressure in the piping of ground equipment and tubing, increasing the hydraulic fracturing efficiency due to periodically generated high pressure that provides dynamic and fatigue fracture of the rock with

the formation of cracks, and provides periodic injection of fluid with a fixer into the cracks, their expansion and consolidation.

The problem is achieved in that the device for hydrodynamic effects on the bottom hole zone of the well contains a liner with holes, high pressure packers, anchors. According to the technical solution, the liner is equipped with a centralizer and in the upper part, through the rod and plunger, is movably and hermetically connected to a cylinder equipped with a check valve and fixed to the pipe string having a weight that provides a pressure under the piston that is greater than the hydraulic fracturing pressure.

The creation of high pressure is carried out periodically and impulse under the influence of the weight of the column when moving it down and is accompanied by the closure of the check valve. In this case, the liquid in the cylinder volume enters the bottom-hole zone, where a periodically pulsed high pressure is created. Ground pump units operate continuously. When the column moves down and the check valve is closed, the pressure in the pipes and manifold rises, and the bypass valves on the pump units open and the liquid enters the receiving tanks, thereby preventing the occurrence of a water hammer. The pressure relief valves designed for maximum pressure or throttling devices mounted on the manifold, piston or valves of the pump unit can perform the functions of the bypass valve.

The operating condition of the device for hydrodynamic effects on the bottomhole zone of the well. Raising and lowering a column with a weight exceeding the fracture pressure

where G _count - the weight of the pipe string in the liquid;

F _piston is the area of the piston, ;

P _gr - hydraulic fracturing pressure.

An example of a specific implementation - well No. 38 of the Vuktylsky gas condensate field. Depth 4966 m. Tournaisian layer. Mountain pressure - 118.84 MPa. Hydraulic fracturing pressure - 93.50 MPa. Generator parameters: piston diameter - 93 mm, tubing weight - 779.46 kN, productivity - 2.17 l / min - developed pressure 129.71 MPa, which exceeds hydraulic fracture pressure by 36.21 MPa.

Spring action bypass valves are adjusted and open at a pressure of 30 MPa.

Figure 1 shows a device for hydrodynamic effects on the bottomhole zone of the well.

The device is installed in the casing 1, perforated opposite the reservoir, and consists of a liner with holes 2, packers 3, anchors 4, tubing or drill pipe 5, rod 6, plunger 7, cylinder 8, check valves 9, hard centralizer 10 Given the high pressure in the bottom-hole zone and the increased longitudinal loads, the layout elements 3, 4, 5, 6 and 8, the area and the gap between the layout and the column 1 are structurally limited and several anchors 4 and packers 3 are installed for reliable fixation, centralizer 10 og anichivaet buckling of the shank and is provided with centralizers and the column tube.

A device for hydrodynamic effects on the bottom-hole zone of a well works as follows.

Previously, before processing and fracturing, the casing 1 is perforated. Then, a liner 2 with holes is lowered into the well. The holes in the liner are designed to exit the fracturing fluid from the device through the perforated casing into the reservoir. Anchors 4 and packers 3 are mounted on a stem 6 with a plunger 7 connected to a shank 2. A cylinder 8 is mounted on a string of centered pipes (drill or tubing) and is equipped with a check valve 9.

The creation of high pressure is carried out periodically under the influence of the weight of the column when it moves downward, automatically, under the influence of pressure drop, closing the upper non-return valve 9. In this case, the liquid in the volume of the cylinder 8 opens the lower non-return valve 9 and enters the bottom-hole zone. Ground units operate continuously when the column moves down and closes the upper non-return valve 9, the pressure in the pipes and manifold increases, and the bypass valves open and the liquid is transferred to the tank.

After lowering the column by the stroke length, the column is lifted, the check valves 9 open, and the bypass valves are closed and the fluid enters the manifold, pipes, into the bottomhole zone and into the formation. And the lower check valve 9 prevents the flow of fluid from the reservoir into the generator in the event of a well and pressure higher than in the generator. The annulus is blocked by packer 3, and the stem assembly 6 — shank 2 is fixed motionless using anchor 4. Bottom zone treatment involves the injection of special fluids, acids, deep fracturing, fixing cracks and cleaning the bottom of the formation.

Claims (1)

A device for hydrodynamic impact on the bottomhole zone, including a casing string, a liner with holes over which packers and anchors are located, characterized in that the liner is provided with a centralizer, a stem, a plunger and a check valve, movably and hermetically connected to a cylinder equipped with a check valve and fixed to the pipe string having a weight that ensures that under pressure the pressure under the piston is greater than the hydraulic fracturing pressure, and the surface pumping units have bypass valves, opening hanging automatically when the column moves down and the check valve closes.