Emulsion type fracturing fluid resistance reducing agent and preparation method thereof

Abstract

The invention relates to a fracturing fluid resistance reducing agent for development of crude oil in low-permeability reservoirs, in particular to an emulsion type fracturing fluid resistance reducing agent and a preparation method thereof. The method comprises the following steps: mixing acrylamide, hydroxyethyl methylacrylate, 2-hydroxypropyl methacrylate, urea and ethylenediamine tetraacetic acid disodium salt, dissolving the formed mixture in water, and regulating a pH value with a sodium hydroxide solution to form a water phase; mixing ethyl distearate-based hydroxyethyl methylammonium methylsulfate with solvent oil to form an oil phase; and subjecting the water phase and the oil phase to mixing and heating, introducing nitrogen, and adding a water-soluble initiator for polymerization so as to form the emulsion type fracturing fluid resistance reducing agent. The resistance reducing agent has the advantages that production time is short, production process is greatly simplified,and production cost is reduced; good mineralization resistance is achieved, and e salt tolerance reaches 120000 mg / L or above; and meanwhile, the friction resistance of a fracturing fluid can be effectively reduced at low concentration, and a resistance reduction rate reaches 90% or above when the concentration of the resistance reducing agent is 500 ppm.

Description

technical field [0001] The invention relates to a fracturing fluid drag reducer for low-permeability reservoir crude oil development, in particular to an emulsion type fracturing fluid drag reducer and a preparation method thereof. Background technique [0002] With the large-scale development of shale gas in the United States, a "shale gas revolution" has been launched in the world, and many countries have launched shale gas exploration and development plans. At present, my country's shale gas field has also set off an upsurge of investment in exploration and production. Shale is an ultra-low permeability reservoir, which cannot provide the seepage channels required for economical exploitation. It is necessary to improve the conductivity of the reservoir through fracturing operations to achieve the purpose of industrial exploitation. At present, the main method of fracturing the reservoir is to add a small amount of drag reducing agent, proppant and some additives to the w...

AI Technical Summary

Problems solved by technology

At present, domestic oil and gas fields mainly use linear rubber, guar gum or imported drag-reducing agents in the production process. Linear rubber and guar rubber have low drag-reducing efficiency and great formation damage, while imported drag-reducing agents are expensive

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