Miscible drive in heterogeneous reservoirs

摘要: A method of improving the sweep efficiency and increasing oil recovery miscible flooding without reducing injectivity injection wells. Two sets wells are used with one set being drilled between other sets. The interwell area a reservoir is pretreated by injecting permeability-reducing agent (preferably polymer) through said first polymer enters more permeable zones partially plugs them, both near away from wellbore. Thereafter, or converted to producing After step permeability contrast heterogeneous reservoirs, slug, that may not be preceded controlled salinity preflush, injected into second There no reduction in wells, becuse has been therethrough. Reduced results improved volumetric increased fluid slug. particularly useful reservoirs communication various where crossflow fluids can detrimental efficiency.