Viscoelastic surfactant type sand-carrying fluid and processing technology thereof

Abstract

The invention discloses a viscoelastic surfactant type sand-carrying fluid which is prepared by the following steps: reacting xanthan gum with a hydrophobic cation bond etherification reagent, and forming a reversible network structure from the modified xanthan gum through electrostatic interaction and hydrophobic association, thereby greatly enhancing the apparent viscosity and the grid structureof the modified xanthan gum; synthesizing a betaine ampholytic surfactant by taking a rosin derivative as a raw material, and carrying out combined copolymerization on the betaine ampholytic surfactant, acrylamide, acrylic acid and N, N-diallyl oleamide to obtain a modified surfactant; using the silane coupling agent for grafting positively charged amino on the surface of the porous ceramic, using succinic anhydride for ring opening to convert the amino into negatively charged carboxyl, and the rock and the propping agent are negatively charged and are subjected to electrostatic repulsion sothat the modified propping agent mixture is better dispersed in the sand-carrying fluid, and the fracturing effect is greatly improved. Reaction conditions are mild, raw materials are cheap, a synthetic route is simple, and sand carrying capacity, salt resistance, temperature resistance and shearing resistance are greatly improved.

Description

technical field [0001] The invention relates to the field of cleaning sand-carrying liquid, in particular to a viscoelastic surfactant type sand-carrying liquid. Background technique [0002] Crude oil is the lifeblood of the national economy and plays a vital role in the development of the national economy and society. With the development of industry and manufacturing, countries are increasingly dependent on oil. The remaining reserves of old oil fields are still considerable. When the total reserves remain unchanged, the enhanced oil recovery is an important measure to stabilize the output of mature oilfields. In order to obtain more oil and gas resources, people use high-pressure pumps to inject liquid with a certain viscosity into the formation at high speed. When the injection speed is greater than the absorption speed of the formation, the formation will rupture or the original small cracks will be opened to form larger cracks. In order to prevent the fracture from r...

AI Technical Summary

Problems solved by technology

[0004] Thickeners are the main additives in fracturing fluids. At present, the commonly used thickeners mainly include (1) natural plant gums: such as guar gum and its derivatives; (2) cellulose: such as carboxymethyl cellulose, hydroxyethyl cellulose, etc. (3) Synthetic polymers: such as polyacrylamide, etc.; but with the needs of development, its disadvantages are gradually exposed, such as low reverse discharge rate, poor degradation effect, incompatibility with the formation, fracturing fluid Not resistant to shearing, storage time is not long, etc.

As a result, the currently used clean sand-carrying fracturing fluid has low viscosity, poor sand-carrying performance, insufficient temperature and salt resistance, and the fracturing effect is not ideal in the actual application process. In order to obtain more oil and gas resources, people urgently need A viscoelastic surfactant sand-carrying liquid with high viscosity, excellent sand-carrying performance, temperature resistance and salt resistance, clean and pollution-free

Images