METHOD OF DEVELOPING WATER-FLOODED OIL POOL Russian patent published in 2001 - IPC

FIELD: oil producing industry, particularly, methods of development of water-flooded oil pools by injection of physico-chemical substances. SUBSTANCE: method involves injection of disperse system into injection well and oil recovery by means of producing wells. Preliminarily determined, on basis of theoretical and laboratory researches is relative phase permeability for water and oil of given formation depending on their concentration. Curve of variation of filtering resistance of mixture depending on its composition is constructed. Injection of disperse system is carried out in two stages. At the first stage, suspension on hydrophilic base is injected with suspension viscosity selected so that disperse system filtering resistance exceeds maximum resistance of water-oil mixture of given formation by a factor of 1.5-5. Then upon reduction of injectivity of injection wells by a factor of 1.8-3.5, water-oil emulsion is injected which is formed from products of said formation. content of water in emulsion is successively increased from 0 to 100%. Suspension disperse phase is used in the form of crushed substance with sizes of particles commensurable with sizes of formation pores, for instance, bentonite clay wood flour, phosphogypsum, etc. EFFECT: higher efficiency of final development of water-flooded oil pool due to creation of blocking effect optimal for concrete formation in reservoirs washed with water; increased coefficient of oil recovery with subsequent stimulation of reservoir containing residual oil. 2 cl, 1 dwg, 2 tbl