METHOD FOR DEVELOPMENT OF NONUNIFORM PERMEABILITY RESERVOIRS Russian patent published in 2017 - IPC E21B43/22 

FIELD: oil and gas industry.

SUBSTANCE: method involves injecting aqueous suspension of pre-crosslinked polymer into the formation. For this purpose, a brand of pre-crosslinked polymer and processing technological parameters are selected taking into account individual geological and physical characteristics of the facility. Initial suspension of the pre-crosslinked polymer is prepared on the well by mixing at least two volumes of water and one volume of reagent, which is particles with initial size from 0.1 to 10 mm. After maturation for not more than 120 min the produced suspension is stirred in tank with water and pumped into injection well in working concentration of 0.1-0.5%. When pumping, the suspension of reagent particles is maintained in suspended state. At the same time, it prevents filtration of reagent particles into low- permeability portion of the reservoir due to initial sizes of reagent particles and their subsequent swelling. The range of permeability threshold below which the reagent is not filtered into the formation is permitted from 200 to 500 md depending on initial fraction and swelling value. Reagent concentration is controlled depending on reagent injection pressure.

EFFECT: increased efficiency when developing non-uniform permeability reservoirs with water drive operation mode due to additional oil production, reduced or stabilized rate of water content growth.

6 cl, 7 dwg, 1 tbl