An oil displacement emulsion stabilized by magnetic nanoparticles

Abstract

The invention relates to the technical field of oil and gas field development. Aiming at the problems of poor thermal stability and easy oil-water separation of existing oil-displacement emulsions, an oil-displacement emulsion stabilized by magnetic nanoparticles is disclosed, including: modified magnetic nanoparticle Fe 3 o 4 @SiO 2 Particles, surfactants and polymers, the preparation method of which is: the modified magnetic nano-Fe 3 o 4 @SiO 2 Granules, surfactants, polymers and deionized water are mixed to form an aqueous phase solution, and ultrasonically mixed for 30-60 min to form a mixed solution; b. Add the oil phase to the above mixed solution, and the speed is homogeneous for 10-15 min to obtain a uniform mixture The oil-water system is allowed to stand at room temperature for 24h-72h, and the excess oil phase and water phase are separated to obtain the finished product. The invention provides an oil-displacement emulsion stabilized by magnetic nanoparticles, which has good stability under high-temperature and high-salt conditions, and the oil-displacement emulsion can significantly improve the recovery rate of low-permeability oil reservoirs.

Description

technical field [0001] The invention relates to the technical field of oil and gas field development materials, in particular to an oil displacement emulsion stabilized by magnetic nanoparticles. Background technique [0002] Traditional emulsion flooding is to inject the emulsion formed by emulsifier (surfactant or surface-active polymer) and crude oil under high-speed stirring into the formation to displace the residual oil after water flooding. Laboratory and field practice shows that emulsion flooding can effectively reduce the residual oil in the formation, and the recovery rate can be increased by about 10%. However, due to the poor long-distance migration and thermal stability of traditional emulsions, they cannot be widely used in oil displacement. In recent years, due to the advancement of nanomaterial technology, a kind of oil displacement emulsion formed by nano solid particles as emulsifier has been developed. Patent No. CN201810462744.3, named as a composite em...

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Problems solved by technology

[0004] The purpose of the present invention is to overcome the problems of poor thermal stability and easy oil-water separation of the oil-displacement emulsion in the prior art, and provide an oil-displacement emulsion stabilized by magnetic nanoparticles, which has good stability under high-temperature and high-salt conditions. Oil displacement emulsion can significantly enhance the recovery of low permeability reservoirs

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