A viscosity-reducing-oil-displacing polymer for conventional heavy oil reservoirs and its preparation method

Abstract

The invention discloses a viscosity-reducing-oil-displacement polymer used in conventional heavy oil reservoirs and a preparation method thereof. The polymer has a monomer with a structure shown in formula (A), wherein R is a branched monomer 3. Generation 0 polyamide-amine, n is 15-25; a, b, c, d, e are the mass percentages of each monomer in the polymer, the total mass fraction is 100%, and a is 0.1%-0.5% , b is 45% to 65%, c is 0.2% to 5.0%, d is 15% to 30%, and e is 16% to 25%. The polymer of the present invention has strong viscosity-increasing ability, and its recovery degree and injectability are superior to those of compound oil displacement system and partially hydrolyzed polyacrylamide, which can reduce the viscosity of heavy oil and increase the viscosity of water phase, and improve the viscosity of conventional heavy oil reservoirs. The purpose of improving the recovery degree is to achieve the multi-purpose and synergistic effects of viscosity reduction and oil displacement.

Description

technical field [0001] The invention relates to an oil displacement agent used in conventional heavy oil reservoirs, in particular to a viscosity reducing-oil displacement polymer used in conventional heavy oil reservoirs and a preparation method thereof. Background technique [0002] With the increase of oil consumption, the production and supply of conventional oil resources in the world is tight, but the heavy oil resources are abundant, which is an important part of the production and development of oil resources. Bohai Oilfield, based on its many years of exploration and practice experience, based on the heavy oil classification standards of China's onshore oilfields, combined with the viscosity distribution range of Bohai heavy oil, further subdivides heavy oil according to viscosity and development mode: conventional heavy oil and unconventional heavy oil . Among them, conventional heavy oil can be subdivided into: conventional type I heavy oil and conventional type ...

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Problems solved by technology

[0010] The purpose of the present invention is to provide a viscosity-reducing-oil-displacement polymer for conventional heavy oil reservoirs and a preparation method thereof. The polymer solves the problem that the existing oil displacement system uses a large amount of surfactant. Strong viscous ability, the recovery degree and injectivity are better than the compound oil displacement system and polyacrylamide, which can reduce the viscosity of heavy oil and increase the viscosity of water phase, improve the recovery degree, and realize the effect of viscosity reduction and oil displacement at the same time

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