Oil field injection well profile control and displacement technology
It can produce comprehensive effects such as increasing viscosity of injected water, lowering resistance of crude oil, oil-water mixed phase and blocking particles in high permeability layer in the formation. As a result, the high permeability layer of the water injection well can be sealed, its water absorption profile can be balanced, the fluidity ratio of oil and water can be reduced, the residual oil in the formation can be further expelled, an active " oil wall" can be formed in the formation, and a " piston" oil displacement effect can be produced, so that the water cut of the oil well can be reduced and the crude oil recovery ratio can be increased.
The oil displacement agent can produce mixed phase action with crude oil, effectively expelling residual oil and forming a crude oil enrichment zone similar to an active " oil wall" in the formation to migrate to the oil well, thus having a long-term profile control effect in the remote well zone. The water shutoff agent can block the high permeability and large pore passages in the formation, balance its water absorption profile, and enable the oil displacement agent to displace oil more effectively. The profile control agent can continuously adjust the water absorption profile of the formation and can drive oil more effectively. It has no harm to the permeability of low permeability formation. after the injection well is treated with it, under the same water injection rate, the water injection pressure decreases or increases slightly.
The technology has wide adaptability and is suitable for sandstone and limestone formations with formation permeability greater than 0.1 μ m2. Water injection wells with a thickness greater than 5m, corresponding oil well crude oil viscosity greater than 1mpa as, and water cut greater than 70 %; Water injection wells with relatively high corresponding rates of oil and water wells in reservoirs with little influence of endless bottom water or edge bottom water.