METHOD FOR REPEATED MULTI-STAGE HYDRAULIC FRACTURING OF FORMATION IN HORIZONTAL WELL Russian patent published in 2020 - IPC E21B43/26 

FIELD: oil, gas and coke-chemical industries.

SUBSTANCE: invention relates to oil and gas industry and can be used as a method for increasing production capacity or injectivity of injection wells, specifically as a method for repeated hydraulic fracturing of oil or gas formation in horizontal well. To implement the method, a tubing string with a packer is lowered into the well. Annular space between casing string and tubing string is sealed. First, the number of hydraulic crack fracturing initiation points is determined in a horizontal wellbore by combining and mutual exchange of data obtained during geophysical survey in horizontal shaft with results of calculations based on geological and hydrodynamic and geomechanical modelling. Depending on the number of defined points of hydraulic fracturing cracks initiation, repeated hydraulic fracturing is performed in several steps, but at least two stages. At each stage, proppant is pumped in amount not less than total weight of injected proppant at first hydraulic fracture, proportionally divided by number of stages. Immediately prior to performing the stages of repeated hydraulic fracturing, calculations are performed to determine number of hydraulic fracturing initiation points by performing diagnostic injections (mini HF).

EFFECT: technical result is improved reliability and speed of repeated hydraulic fracturing in wells equipped with unbalanced shanks.

1 cl, 1 dwg