PetroChina Company Limited
Method for in-depth profile control and displacement of low-permeability oil reservoirs

Abstract:

The present invention provides a method for in-depth profile control and displacement of low-permeability oil reservoirs, comprising: sequentially injecting a flexible and elastic particle-containing pre-slug, a polymer microsphere-containing main slug and a flexible and elastic particle-containing protective slug into an oil layer, and the three slugs have a volume ratio of total injection amount of 1-2:6-8:1-2. The invention provides a method for in-depth profile control and displacement by using styrene-based flexible and elastic particles in combination with the polyacrylamide polymer microsphere, wherein the flexible elastic particles can block cracks and large pore channels of the oil layer, and the polymer microsphere can displace the remaining oil in the oil layer. In the present invention, different slugs of profile control and displacement system are combined to achieve the objective of blocking cracks and large pore channels, displacing crude oil, and improving oil well recovery.