Patent ID: 11912932
Assignee: CHINA UNIVERSITY OF PETROLEUM (EAST CHINA)
Field: Basic materials chemistry (Chemistry)
Classification: CPC C  Y | IPC C  E

Claim 3:
4. The encapsulated polymer flooding method for enhancing oil recovery according to claim 1, wherein in the step (iv),
an anti-shearing test is performed on capsules at different mass concentrations to determine a critical shear rate at which the capsule is broken at ground temperature, that is, the anti-shearing performance of the encapsulated polymer;
a laboratory aging test is performed to determine a release rate and the viscosification performance of the polymer in the formation, that is, the sustained release and viscosification performance, a relationship between the viscosity of the polymer and time satisfies μ=αtnμmax, μ is the viscosity, μmax is the maximum viscosity of the polymer capsule after complete release, t is time, and α and n are coefficients;
a single core encapsulated polymer injection test is performed, and a pressure change during injection, that is, the injection performance, is recorded,
a double-pipe permeability ratio seepage test is performed, a profile improvement coefficient is recorded to evaluate the profile control performance, and the optimal profile control concentration is denoted as c1; and
the expected performance requirements are: the critical shear rate of the encapsulated polymer is not less than 600 s−1, the maximum viscosity of the polymer capsule after complete release is not less than 20 mPa·s, pressure during injection of the encapsulated polymer is less than 5 times of pressure during injection of water, and the profile improvement coefficient is greater than 50%.