METHOD FOR DEVELOPMENT OF HETEROGENEOUS FORMATIONS Russian patent published in 1995 - IPC

FIELD: development of oil fields. SUBSTANCE: method for development of heterogeneous formations includes injection through injection well and producing in formation of fringes of hydrogen sulfide-containing sewage. Injection of this fringe results in oil displacement from highly permeable zones and passages and establishment of tonguelike water encroachment of formation. Then, iron-containing water is injected to effect blockage of highly permeable formation part, followed by injection of fringe of hydrogen sulfide containing water. Volume of fringe is determined by calculation. For subsequent displacement of oil from highly permeable part of formation, blocked by injection of iron-containing water, reagent dissolving iron salts is injected. This reagent is used in form of acid. Then, injected is displacing fluid in form of hydrogen sulfide-containing water. This promotes advance of displacement front inside formation with increased covering of formation by new passages and pores and also by part of formation blocked beforehand. EFFECT: increased covering of heterogeneous formations due to straightening the front of oil displacement. 5 dwg