| 摘要 |
<p>The present invention pertains to the crude-oil extraction industry and essentially relates to methods for extracting crude oil from non-uniform geological formations by carrying out isolation operations in order to level-off the injectivity profile of injection wells and to reduce the water ingress into production wells. This method involves injecting into the formation aqueous solutions of at least two gel- or deposit-forming agents in the form of an aggregative and stable reverse-type emulsion in a low-viscosity hydrocarbon solvent (petrol, kerosene, etc.). The method also involves previously dissolving in said solvent from 5 to 20 wt.% of a concentrate of porphyric and asphalt-tar components from crude-oil. For each aqueous solution of the agent used, the method involves preparing previously and separately 50 vol. % of the aggregative and stable reverse-type emulsion in which the size of the particles (globules in the emulsified aqueous solution of the agent) is commensurate with the dimensions of the pores in the highly permissive sections of the formation. Before being injected into the formation, the previously prepared emulsions of gel- or deposit-forming agents are mixed according to various volumetric proportions. Once the mixed emulsion is injected, the method involves injecting into the formation a hydrocarbon solution of a demulsifier for the reverse emulsion in order to break down the same and to form in the highly permissive sections of the formation a water-isolation barrier that consists of a viscous and resilient gel (or a non-soluble deposit).</p> |
