RU2099531C1 - Device for pulsed stimulation of bed - Google Patents

Abstract

FIELD: mining industry; may be used in intensification of mining of loose minerals through borehole, in geological prospecting for decolmatage of borehole zone. SUBSTANCE: device includes string of agent supplying pipes consisting of sections separated by seats for trip valve. Diameter of hole of each lower seat is smaller than that of overlaying one. Installed concentrically relative to every section of agent supplying pipes is bypass pipe which forms annular hollow by its internal surface together with external surface of agent supplying pipe. Made in each section of agent-supplying pipe are inlet channels located under its seat, and outlet channels located under seat of adjacent underlaying section. Channels communicate annular hollow of bypass pipe with internal hollow of section of agent-supplying pipe. EFFECT: increased oil mobility in formations. 2 cl, 3 dwg

Description

 The present invention relates to techniques for the mining industry to intensify the development of loose minerals through wells, to the exploration industry for raskolmatization of the water intake (water-absorbing) borehole zone and to the oil industry to increase the mobility of oil in the channels of the reservoir.

A device for hydraulic fracturing, including a string of tubing and a packer. In the pipe string, saddles are installed for the valves being reset, and the diameter of the upstream seat is larger than the previous one. A check valve is installed in the packer, which communicates the sub-park space with the super-packer [1]
In the known design, it is difficult to fix between pulses of certain periods of time.

In another design of the production projectile, which has saddles on the inner surface of the lower part of the agent-supply string for resetting valves to control certain time intervals between pulses and to create favorable conditions for the advance movement of the agent jets relative to the dump valve after extruding the latter from the seat opening, the cross-sectional area of the channel of the agent-supply pipes is increased relative to the cross-sectional area of the waste valve; the channels of the seats are made inclined; between the saddles, the agent-feeding pipe sections are equipped with ball limiters, which are made in the form of a perforated screw pipe connecting the channels of the seats; ball limiters mounted on the inner walls of the supply pipes are made inclined and are located in the same vertical plane [2]
Despite the increase in the gaps between the waste valves and the inner walls of the sections of the agent supply pipes, the increase in the length of the trajectories of the movement of the waste valves relative to the path of the agent’s movement is practically difficult to achieve strictly maintained time intervals between the hydraulic pulses.

 The present invention is aimed at improving the operational efficiency of the pulse action on the formation by hydraulic braking of the movement of the waste valves when they are pressed through and departing from the holes of the seats and the establishment of strictly fixed time intervals between pulses. This is especially important when using short sections of agent-supply pipes, when using which the transmission of impulses in the form of hydroblows into the well and further into the reservoir is especially effective.

 This goal is achieved by the fact that the device for pulsed impact on the reservoir includes a column of supply pipes, consisting of sections separated by saddles under the dump valves.

 The diameters of the holes of each lower saddle are smaller than the above. A bypass pipe is installed concentrically to each section of the agent supply pipes, forming an annular cavity with its inner surface and the outer surface of the agent supply pipe. In each section of the agent-feeding pipe, inlet channels are placed under the saddle, and output channels located above the saddle of the adjacent upstream section. The channels communicate the annular cavity of the bypass pipe with the inner cavity of the section of the agent supply pipe.

 The diameter of each of these inlet and outlet channels is smaller than the inner diameter of the sections of the agent supply pipes, but in total the inlet and outlet openings have a larger cross section than the channels of these sections. The cross section of each annular cavity between the bypass and agent supply pipes is also larger than the total cross section of individual input and output channels.

 In FIG. 1 shows the proposed device, a vertical section; in FIG. 2 lower section of the device with a control valve; in FIG. 3 is a sectional view of the device of FIG. 1 through I-I.

 The device includes a column of supply pipes 1, in the lower part consisting of sections 2 with internal cavities 3.

 Section 2 is divided by saddles 4 under the dump valves 5 of elastic material. The diameter of the holes 6 of each lower saddle is less than the above. Concentric to each section of the agent-feeding pipes 2, a bypass pipe 7 is installed, forming an annular cavity 8 with the agent-feeding pipe. Inlet sections 9 are placed in each section of the agent-feeding pipe, placed under its saddle 4, and outlet channels 10, located under the saddle 4 of the adjacent downstream section. The ends of the agent supply and bypass pipes have 4 sealed joints with saddles. Introductory 9 and outlet 10 channels communicate an annular cavity 8 of each bypass pipe 7 with an internal cavity 3, respectively, of the section of the agent supply pipe. On the bypass pipe 7 of the lower section, a packer 11 with a control valve 12 can be installed.

 The device operates as follows. A pipe string 1 is lowered into the well with agent supplying sections 2 and concentric by-pass 7 tubes mounted on them, separated by saddles 4. After the packer has closed the well, the fluid is removed from the well (for example, by air-lift). Next, a waste valve made of elastic material, which has a diameter slightly larger than the hole of the upper seat 4, is lowered into the pipes 1.

 Then the pipes 1 are filled with liquid to create a hydropercussion impulse. After filling the pipe string 1 with liquid on the upper seat 4 with valve 5, a hydraulic pressure is created equal to the height of the liquid column.

 In the upper part of the compression column 1 and gas (carbon dioxide, nitrogen or air) creates excessive pressure to force the relief valve 5 through the hole 6 of the upper seat 4.

 Thus, a hydraulic shock to the formation is carried out by the dynamic force of the falling liquid column. Due to the fact that the waste valve 5 is forced into the inner cavity 3 of the first section of the agent-feeding pipes 2 of small cross section with high hydraulic resistance by the action of forces acting on it, the movement of the latter slows down. In turn, the agent (squeezing liquid), experiencing relatively less hydraulic resistance when moving through the inlet channels, the annular cavity of the bypass pipe rushes at high speed into the cavity 3 of the downstream sections of the agent supply pipes.

 At the same time, a hydraulic shock is transmitted to the well and the borehole zone. Next, the waste valve is installed on the second seat from the top, and under the action of hydraulic pressure created by a column of liquid in the agent-supply pipes and pumped by the gas compressor, is secondly forced into the next cavity of the agent-supply pipe section. In this case, the hydraulic shock is repeatedly transmitted to the well and the near-wellbore zone.

 Thus, the forcing of one exhaust valve through all sections of the agent supply pipes creates a low-frequency pulse effect on the receiving, absorbing part of the well, which contributes to an increase in the permeability of the formation.

 In the process of hitting the liquid against the bottom, the compressed gas is released through the valve 12 of the packer 11. If after bursting through the device several balls, the formation was not broken and its permeability did not increase, then the well is freed from the liquid and the entire process of impulse action is repeated.

 The economic efficiency of the application of the invention is to save the energy of surface equipment, increase the strength and frequency of hydrodynamic effects on the bottom and the receiving part of the well, and create a strictly periodic impact on the rock mass of the mineral collector. At the same time, mining is significantly intensified.

Claims (2)

 1. Device for impulse action on the formation, including a column of agent-supply pipes, consisting of sections separated by saddles under the throttle valves, and the diameter of the holes of each lower seat is less than the diameter of the upper one, characterized in that a bypass pipe is installed concentrically to each section of the agent-supply pipes, forming with the agent-supply the annular cavity by the pipe, and in each section of the agent-feeding pipe there are made input channels located under its saddle and output channels placed above the saddle of the adjacent lower the laid section, for communication of the annular cavity of the bypass pipe with the inner cavity of the section of the agent supply pipe.  2. The device according to claim 1, characterized in that the diameter of each of the input and output channels is less than the inner diameter of the sections of the agent supply pipes, but in total the input and output channels have a cross section greater than the channel section of these sections, and the cross section of the annular channel between the sections of the agent supply pipes and bypass pipes is equal to or greater than the total cross section of the input and output channels, respectively.

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