METHOD OF WELL OPERATION AT STACK OIL DEPOSIT Russian patent published in 2008 - IPC E21B43/14 

FIELD: mining.

SUBSTANCE: method involves separation of upper thick stratum and lower weaker strata in a well. First the upper thick stratum is developed until water cut reaches 75-90%, then simultaneous separate well operation is performed. Upper weak stratum is perforated. Upper thick stratum and perforated upper weak stratum are disintegrated. Stratum fluids are extracted simultaneously and separately, with preferred extraction from the weak stratum till water cut of the well product drops below 75-90%. When the water cut of well products reaches 75-90%, next deep weak stratum is perforated, the perforated stratum and upper strata are disintegrated, stratum fluids are extracted simultaneously and separately, with preferred extraction from the weak perforated stratum till water cut of the well product drops below 75-90%. When the water cut of well products reaches 75-90%, next deep weak stratum is perforated, the operation being repeated until the lowest weak stratum is developed and water cut of well product reaches 75-90%. Influx and water cut of each stratum are defined, completely water-encroached strata are isolated, and the rest of the strata is processed by general filtering.

EFFECT: increased stock production from strata.

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