Amphoteric cross-linked polymer microsphere-hydrophobic associative polymer profiling/flooding agent and application thereof

Abstract

The invention relates to an amphoteric cross-linked polymer microsphere-hydrophobic associative polymer profiling / flooding agent and an application thereof. The profiling / flooding agent comprises 0.01-0.5% of amphoteric cross-linked polymer microspheres, 0.01-0.5% of water-soluble hydrophobic associative polymer and balance of water. The amphoteric cross-linked polymer microspheres are prepared through a polymerization reaction in an inert environment. In the reaction system of the polymerization reaction, polymerization monomers account for 1.0-40% of the reaction system by mass; cross-linking monomer accounts for 0.001-3% of the reaction system by mass; the polymerization monomers are anionic monomer, cationic monomer and nonionic monomer, wherein a molar ratio of the anionic monomer to the cationic monomer to the nonionic monomer to the cross-linking monomer is 2.5-25: 2.5-25: 50.0-95: 0.1-6. With the composite deep profiling / flooding agent provided by the invention, water injected reservoir recovery rate can be substantially improved. The profiling / flooding agent is more suitable for waterflooding reservoirs with nonuniform porous media.

Description

technical field [0001] The invention relates to a cross-linked polymer microsphere-hydrophobic association polymer regulating and displacing agent, in particular to an amphoteric cross-linking polymer microsphere-hydrophobic associating polymer regulating and displacing agent and its application, belonging to the field of petroleum industry. Background technique [0002] At present, the early development of oil fields has entered the middle and late stages of water flooding oil recovery. How to further increase the volumetric sweep coefficient and swept volume of injected water and economically and effectively exploit existing oil fields is one of the major issues to be solved in the petroleum industry. Among them, the enhanced oil recovery technology Development and application played an important role. [0003] With the deepening of research, the influence of reservoir heterogeneity on the sweep coefficient of water flooding and chemical flooding fluid has attracted increa...

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Problems solved by technology

[0005] However, with the deepening of research and repeated field tests, the contradiction between the currently used polymer flooding and cross-linked polymer flow weak gel system for the purpose of increasing the viscosity of the displacement fluid and the field implementation conditions has gradually been exposed. , such as: For strongly heterogeneous reservoirs, although the rheological properties of the injected displacement fluid can produce a certain macroscopic liquid flow redirection ability, compared with water well profile control, control and flooding, etc. based on high-permeability pore plugging As far as the current technology is concerned, its liquid flow redirection ability is relatively weak, and it is easy to cause premature breakthrough of displacement fluid through the high-permeability layer and the dominant channel formed during the long-term water injection process, which not only affects the displacement efficiency of polymer flooding, but also affects the follow-up Oil-water separation system brings a series of problems

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