Method for establishing effective barriers to production of undesired fluids in the recovery of oil

摘要

A reservoir-engineering method wherein horizontal barriers against flow of undesired reservoir fluids into an oil well are formed by density-controlled injection of a barrier-forming fluid mixture having a large penetration depth into the reservoir. A barrier-forming injection fluid may be placed at the fluid contacts in the reservoir independent on whether it is injected at these, in that it has an intermediate density in relation to the reservoir fluids between which it is desired to be placed. Particularly suitable barrier-forming injection fluids are foam-forming chemicals which in several ways may be converted into mobility reducing barriers in situ.