METHOD OF SELECTIVE RESTRICTION INFLOWS IN DEVELOPMENT WELLS Russian patent published in 2002 - IPC

FIELD: oil and gas producing industry, particularly, methods of selective restriction of water inflow in development wells and equalization of flood front in injection wells. SUBSTANCE: method includes injection into bottom-hole formation zone of invert emulsion based on mineralized aqueous dispersed phase and hydrocarbon dispersed medium with addition of emulsifiers in the form of chemically modified highly dispersed silica possessing properties of solid nonionic surfactants, particularly, chemically modified highly dispersed silica with discrete particles sizing 0.005-0.1 mcm with hydrophobic degree of 20-90% in amount of 0.3-3.5 wt.% of all volume of emulsion. Hydrocarbon dispersed medium is used in the form of oil or products of oil processing. In this case, for increase of emulsion stability, added to oil is water repellant in the form of chemically modified silica with discrete particles sizing 0.005-0.1 mcm and with hydrophobic degree of 100% in amount of 0.1-1.0 wt.% of all volume emulsion. In this case, dispersed phase to dispersed medium ratio in emulsion varies within 1/1 to 6/1. Injected into bottom-hole formation zone is from 0.5 to 8.0 cu.m of invert emulsion per meter of efficient thickness of formation, and it is forced into formation by formation water. EFFECT: produced stable invert emulsion based on fresh or mineralized water with ratio of water to hydrocarbon phase of 1/1 to 6/1, and chemically modified amorphous silicas. 6 cl, 1 dwg, 1 tbl, 11 ex