METHOD FOR REACTANT-WAVE TREATMENT OF BOTTOMHOLE FORMATION ZONE WITH FILTRATION PRESSURE WAVES Russian patent published in 2016 - IPC E21B43/18 E21B34/06 

FIELD: mining.

SUBSTANCE: invention relates to methods of treatment of bottomhole zone of formations of wells and can be used in oil and gas industry. Method involves lowering to treated well interval equipment assembly on pipes with packer and valve devices and a jet pump. Treated well interval is isolated. Method includes wave treatment of bottomhole formation zone with filtration pressure waves by generating multi-cycle repression and depression on formation of adjustable amplitude and period. Method includes pumping chemicals into formation for treatment of bottomhole formation zone by pumping a calculated volume to pipes, adjustment to well bottomhole and forcing into process fluid into formation. Waiting for reaction of chemicals. Reaction products are pumped out from formation by creating depression and influx from formation. Control and registration of intake capacity, flow and pressure during treatment with determination of filtration parameters of bottomhole formation zone. Wave treatment is performed with generation in bottomhole formation zone of pressure waves simultaneously and at least in three frequency ranges. In sub infra-low frequency range generating filtration waves of first order with period of 1 to 2 hours. In sub infra-low frequency range generating filtration waves of second order with period of 0.01 to 0.1 hour. In low-frequency range generating third-order filtration waves with period of 0.0001 to 0.001 hour. First and second order waves are generated by generating multi-cycle repression and depression on formation in treated interval of well shaft with limitation of pressure of not more than permissible for cement ring and casing string. Waves of third and higher orders are generated by providing pulse shape pressure when generating multi-cycle depression and repression with steepness of fronts of not less than 0.1 MPa/s. Injection of chemicals and pumping of reaction products is performed at appropriate half-periods of waves of first order. Treatment of waves of second and higher orders is carried out at least while waiting for reaction of chemicals after chemical injection into formation. Generation of depression and repression on formation is carried out using circulation valve of multi-cycle action with a jet pump of insert type with supply of working pressure in pipe string.

EFFECT: technical result is intensification of oil recovery by increasing or restoration of water permeability of bottomhole formation zone.

5 cl, 3 dwg