Micro-scale dynamic dispersion agent and preparation method thereof

Abstract

The invention discloses a micro-scale dynamic dispersion agent and a preparation method thereof. The micro-scale dynamic dispersion agent comprises, in weight percent, 0.075%-0.15% of hyper-branched polymer, 0.005%-0.0125% of citrate, 0.0075%-0.015% of aluminum trichloride, 0.005%-0.01% of sulfite and the rest water, wherein the hyper-branched polymer is polyamide-amine hybrid nano-silica hyper-branched polymer. The preparation method includes the steps: sequentially adding hyper-branched polymer solution, citrate solution, aluminum trichloride solution and sulfite solution; adding oilfield injection water to prepare micro-scale dynamic dispersion agent base solution; placing the micro-scale dynamic dispersion agent base solution in a constant temperature oven and aging the micro-scale dynamic dispersion agent base solution into the agent. The dynamic dispersion agent can automatically change micro-scale under the condition of different mineralization degrees and is applicable to deep profile control of an oil reservoir with medium-high temperature and a wide mineralization degree, adaptivity of the oil reservoir is realized, and injection water development effects are improved.

Description

technical field [0001] The invention relates to a micro-scale dynamic dispersant and a preparation method, belonging to the fields of nano-micro materials and oil field chemistry. Background technique [0002] After a short period of elastic energy extraction, the oil field enters the stage of supplementary energy development. Water flooding is still the preferred technology for oilfield development. The water flooding stage endows other functions besides replenishing formation energy and has become a hot topic in the world's oil industry. After years of water injection development, the oilfield has entered the "double high stage" of high water cut and high water production. At the same time, the contradiction between the profile and the plane is prominent, water channeling is serious, and it is difficult to stabilize production. Laboratory research and field tests have proved that chemical flooding is an important strategic technology to improve the recovery rate and injec...

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Problems solved by technology

However, the CDG formed by the linear polymer based on partially hydrolyzed polyacrylamide (HPAM) has the following obvious deficiencies: ① The linear molecule cannot be coiled enough under solution conditions, so it is necessary to add inorganic salts to make the molecular coils coil enough to form intramolecular crosslinks ;②Gel forming conditions are harsh and poor adaptability. CDG is mainly intramolecular crosslinking, requiring low concentration of polymer and crosslinking agent system. Polymers with lower concentrations cannot form colloidal dispersion gels; ③ It is difficult to form gels in the formation, affected by diffusion, dispersion, retention (adsorption, mechanical trapping), shear degradation, etc., the polymer seepage process in the formation Medium concentration and viscosity loss are serious. In order to solve the above unfavorable factors, the concentration of the polymer is usually increased, which causes the polymer to form a weak gel mainly due to intermolecular crosslinking during the initial injection process, increasing the injection pressure and failing to reach the reservoir. deep regulation

The above unfavorable factors have hindered the popularization and application of CDG in my country's oilfields

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