METHOD OF RESERVOIR HYDRAULIC FRACTURING WITH SELECTIVE FLOW INJECTION Russian patent published in 2015 - IPC E21B43/26 E21B43/16 

FIELD: oil and gas industry.

SUBSTANCE: group of inventions relates to secondary methods of HC extraction from the underground reservoirs, in particular to methods of the hydraulic fracturing without the proppant, as well as to the selective injection to some underground reservoirs. As per the method the selective stratum of stratums set is isolated along the well bore in the underground section from rest stratums of the set. The selective injection is used to supply fluid to the selective stratum in the stratums set. At that the fluid is supplied to the selective stratum regardless of the fact weather the fluid was supplied to the neighbouring stratum of the stratums set. Isolation means isolation of the stratums set from pressure acting on the selective stratum when the fluid is supplied to the selective stratum. Hydraulic fracturing of each stratum of the stratums set is performed. Testing of the stepwise pressure variation is performed for at least one stratum of the stratums set. Testing of the stepwise pressure variation includes opening of one of the reservoir stratums in the stratums set by the fluid injection to the well bore. At that one of the stratums is opened at specified pressure. The fluid backflow is ensured such that one of the reservoir stratums is closed. Re-opening of the one of the reservoir stratums is performed for one or more times. At that the reservoir opening pressure is reduced each time. Mode is determined when the reservoir opening pressure is below the injection pressure at which the reservoir injection ensures the fluid supply to the stratums set. As response to determination that the reservoir re-opening pressure is below the injection pressure the test is completed by stepwise pressure variation.

EFFECT: increased efficiency of HC production.

21 cl, 7 dwg