METHOD FOR NON-STATIONARY COLLECTION OF LIQUID FROM A FRACTURE-POROUS TYPE COLLECTOR Russian patent published in 2019 - IPC E21B43/20 E21B49/08 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil industry and can be used in development of oil deposit represented by collector of fracture-pore type. Oil recovery coefficient is increased due to involvement of previously undrained stocks of matrix oil into development. Liquid is extracted from collector of crack-pore type through production wells in non-steady-state mode with change of flow rate from maximum to minimum, wherein preliminary hydrodynamic analysis of wells is performed to determine time of fluid flow from pores to cracks, presence of non-stationary mode is determined by pulsating change of bottomhole pressure during analysis of pressure recovery curve (PRC), value of maximum and minimum yield is determined by minimum and maximum pressure on PRC, at which pulsating pressure change starts and ends, and the well is brought to the stationary mode, and duration of the operation period at the maximum and minimum yield is determined by the time of the non-stationary mode completion. Well is started in operation at minimum feed mode with parallel sampling and performing oil properties optical analysis to determine light absorption coefficient, besides, watering is determined, then changing the operating mode of the well by increasing extraction and parallel sampling is carried out to study optical properties (coefficient of light absorption) of oil, then again changing the operating mode of the well to determine the light absorption coefficient, and corresponding changes in the operating mode and sampling for investigating optical properties of oil is carried out until maximum extraction is determined, determined by pump disruption, according to the research results, the operating mode is determined, which corresponds to the minimum light absorption coefficient of oil, which indicates the flow of unreformed oil from the matrix into the cracks, this mode is set and the well is operated at the given mode, performing periodic sampling of oil for control of optical properties and water cut, with increase in oil absorption coefficient and water content higher than maximum allowable level or yield below economic profitability, well is stopped, wherein duration of stop period corresponds to time of oil flow from matrix to cracks, which is determined based on results of hydrodynamic investigations, then well is put into operation in mode corresponding to minimum coefficient of light absorption.

EFFECT: increased oil recovery coefficient of reservoir represented by crack-pore type collector.

1 cl, 3 dwg