Multi-crosslinking core-shell type polymer microsphere, modifying and flooding agent, and preparation method and application thereof

Abstract

The invention relates to a multi-crosslinking core-shell polymer microsphere, a modifying and flooding agent, and a preparation method and application thereof. The method mainly solves the problems that in the prior art, polymer microspheres are mainly of homogeneous structures, the variety of used cross-linking agents is single, only one chemical crosslinking agent is introduced generally, and although the microspheres can expand to a certain degree, the profile control and plugging performance on medium-high permeability oil reservoirs is poor. The multi-crosslinking core-shell type polymermicrosphere comprises a polymer I inner core and a polymer II outer shell, and molecules of the polymer I and the polymer II independently contain an inorganic crosslinking agent structural unit and an organic crosslinking agent structural unit, so that the problems are well solved, and the microsphere can be applied to field application for increasing the recovery ratio of an oil field.

Description

technical field [0001] The invention relates to a multi-crosslinked core-shell polymer microsphere, a control and displacement agent, a preparation method and an application thereof. Background technique [0002] Water production from oil wells is a common problem in oilfield development, especially in old oilfields developed by long-term water injection. Due to the heterogeneity of the reservoir and the difference in the viscosity of oil and water, the injected water easily enters the high-permeability zone or fracture and bypasses the medium-low permeability zone, causing oil and water to burst along the high-permeability zone or fracture between the water injection well and the production well. And fingering, resulting in premature water flooding of production wells, decreased oil production and increased water cut, thereby reducing the sweep coefficient of injected water and resulting in low or no production of medium and low permeability layers. Improving the sweep coe...

AI Technical Summary

Problems solved by technology

[0005] One of the technical problems to be solved by the present invention is that there is a contradiction between the strength and water-absorbing swelling performance of polymer microspheres in the prior art, which causes the problem that the expansion performance, elasticity, and heat-resistant stability of the polymer microspheres cannot be simultaneously enhanced. Provide a kind of multiple cross-linked core-shell polymer microspheres, which overcomes the contradiction between the strength and water-swelling performance of polymer microspheres in the prior art. The multiple cross-linked core-shell polymer microspheres contain inorganic , organic crosslinking agent, has the advantages of microsphere expansion performance, elasticity, heat resistance and stability