Patent RU-2734301-C1 (RU)
Title: Method of hydrodynamic impact on bottom-hole formation zone and device for its implementation
Inventor: FURSIN SERGEJ GEORGIEVICH
IPC: E21B28/00
Filed: 2020-02-18
Granted: 2020-10-15
Abstract: FIELD: mining. 
     SUBSTANCE: invention relates to operation of wells, in particular, to treatment and development during construction or repair thereof, and can be used to increase efficiency of extraction of hard-to-recover hydrocarbon reserves in complex geological and process conditions. In the method of hydrodynamic impact on bottom-hole formation zone, which involves lowering of jet pump housing to the well with central core of active medium supply, shank with internal channel and two upper and lower packers, isolation of annular space of well by two packers in bottom and roof of manifold interval with installation on this interval of shank, activation of well flushing and feed of nozzle of jet pump with active medium with outlet through diffuser into above packer zone of upper packer, active medium flow switching from jet pump to shank and back to create depression and repression cycles in well, pumping in passive medium depression cycles – formation fluid through shank and mixing chamber with passive medium supply channel, pumping into well in cycles of depression and overflush into formation in cycles of active medium repression – process fluid through shank is possible with hydraulic fracturing of formation, generation in cycles of depression and repression of periodic pulses with energy concentration, according to the invention in inhomogeneous low-permeable section after insulation of annular space of the well, the shank is moved back-and-forth between two packers and placed at a given depth, namely in a low-permeable part of the cut, and at this depth additional treatment of formation is carried out for leveling and increasing of collector permeability, besides, periodic pulses are generated with due allowance for direction of medium flow in shank be independent of value of fluid inflow during depression or its absorption during repression, wherein a hydraulic motor is used, which is successively connected to the nozzle with an active medium with the possibility of selective periodic coverage of passive medium supply channel in cycles of depression or made in the housing connecting the annular space in cycles of repression, and additional treatment of formation is carried out by switching flow of active medium from jet pump to shank and back by axial movement of pipe string while fixing in housing well, which is made composite, at that, components of housing relative to each other are shifted, active medium flow is switched from implosive mode from nozzle to shank end and cascades of sporadic cavitation-impact pulses are generated, which are differentially concentrated in low-permeable part of collector. To achieve technical result in disclosed device for hydrodynamic effect on bottom-hole formation zone containing pipe string, shank with internal channel, upper and lower packers, located between shank and pipe string housing of jet pump with central stem of active medium supply, connected to it nozzle, diffuser with outlet into above-packer zone of upper packer and mixing chamber with passive medium supply channel, according to invention housing is made in the form of spring-loaded telescopic connection, which upper part contains hydraulic motor with flow interrupter at output shaft end, plug with nozzle, diffuser installed at nozzle level, check valve and connecting with annular space channel, and lower part is mating channel communicating annular space, mixing chamber with passive medium supply channel and hydraulic anchor, wherein the telescopic connection components with the open hydraulic anchor are able to approach and displace with the axial load of the pipe string changing, wherein when approaching they form sealed plug-to-cylinder pair and jet pump, and in the course of the implosion removal, the accumulated flow of the active medium is directed to the tail ending in the cavitator with the radial nozzles, the upper and lower flow openings and the three-position valve arranged there between, wherein cavitator is connected by locks to upper and lower packers, wherein upper packer is made through and installed on bushing, which with seal and possibility of axial movement is put on shank with external smooth surface, and lower packer is made blind in form of detachable and attachable bridge with possibility of mechanical interaction with three-position controlled valve. 
     EFFECT: increased amplitude of periodic pulses at both depression and repression on the formation, increased reliability of the device in complex geological and process conditions and possibility of processing also heterogeneous low-permeability reservoirs. 
     2 cl, 6 dwg