Self heat-generating and gas-generating clean fracturing fluid

Abstract

The invention relates to a self heat-generating and gas-generating clean fracturing fluid comprising the raw materials of, by mass: 0.2-0.5% of a thickening agent, 2-4% of a structural enhancer, 2-15% of a heat generating agent A, 2-10% of a heat generating agent B, 2% of a structural enhancer solvent, 1-5% of a heat generating catalyst, 0.1-1% of a cleanup additive, 0.05-1.0% of a gel breaker, 0.05-0.15% of a broken plastic additive, and balance of water. The fracturing fluid has good temperature resistance, good shearing resistance, and sand-carrying property. The fluid can automatically generate heat and gas, such that the fracturing fluid is foamed in stratum. The fluid has low filtration loss. Gel breaking can be carried out with conventional persulfate and stratum oil, gas, and water dual gel breaking manner. Quick flow-back after pressure can be realized, and low-pressure oil and gas well self-spraying flow-back effect can be greatly improved. No residue and low harm is caused. The fracturing fluid can be used in fracturing modification of middle-shallow-stratum high-pour-point oil, crude oil with high viscosity, and low-pressure low-permeability oil and gas reservoirs.

Description

technical field [0001] The invention relates to a fracturing fluid used in the fracturing stimulation process of oil and gas wells, in particular to a self-generated heat and gas clean fracturing fluid. Background technique [0002] The foam fracturing fluid used in the reservoir fracturing reconstruction of low-pressure and low-permeability oil and gas reservoirs with high pour point oil and thick original viscosity requires special equipment for transportation and pumping of nitrogen and carbon dioxide. The procedures are complicated, the pipeline friction is high, the pump pressure is high, the pipeline is easy to freeze and block, and the leaked nitrogen and carbon dioxide may cause frostbite to the construction personnel, so the construction risk is high, so the use of reservoir fracturing is limited; Using conventional water-based guar gum fracturing fluid, the inherent residue will block part of the flow channel, thereby reducing the conductivity of the fracture, so t...

AI Technical Summary

Problems solved by technology

At present, the self-generating heat-generating fracturing fluid system is based on the conventional water-based modified guar gum fracturing fluid, adding a certain amount of sodium nitrite, ammonium chloride, hydrochloric acid and corrosive agent. Thermal agents, when they are mixed in the presence of catalyst hydrochloric acid, heat and gas will be generated, and the generated gas will be distributed in the liquid to form a performance similar to that of foam fracturing fluid, but the amount of residue contained cannot be effectively reduced, and its damage is high, affecting the pressure. domestic and foreign experts have introduced thermogenic chemical reactions into the viscoelastic surfactant fracturing fluid system, which has no residue and low damage. However, the gel breaking needs to rely on formation oil, gas, and water, and the gel breaking time is long and cannot be achieved. fast flowback

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