Multifunctional foam fracturing fluid and preparation method thereof

Abstract

The invention provides a multifunctional foam fracturing fluid and a preparation method thereof, and the multifunctional foam fracturing fluid is an aqueous solution, the solvents include a self-generating agent is sodium nitrite; a multifunctional agent is ammonium chloride; an initiator is paraformaldehyde; a foaming agent is one or more of tetradecyl trimethyl ammonium bromide, hexadecyl trimethyl ammonium bromide and didecyl dimethyl ammonium bromide; and a foam stabilizer is one or more of erucamide propyl betaine, oleamide propyl betaine, erucamide propyl hydroxy sulfobetaine and hexadecyl hydroxypropyl sulfobetaine. The corrosion of a strong acid environment to a tubular column is delayed, the supply of hydrogen ions is ensured, and the hydrogen ions are prevented from being continuously consumed under a gas generation condition; the self gas generation reaction is violent, the generated foam is more and stable, the proppant can be ensured to be carried into the deep position of the stratum, the sand blocking accident is not caused, a large amount of heat can be released, the adsorbed methane is desorbed, and the yield increasing efficiency of the foam fracturing fluid is improved.

Description

technical field [0001] The invention belongs to the technical field of foam fracturing fluid, and in particular relates to a multifunctional foam fracturing fluid and a preparation method thereof. Background technique [0002] Foam fracturing fluid has the advantages of high viscosity, strong sand-carrying capacity, low fluid loss, and rapid flowback. It has been applied in the hydraulic fracturing of unconventional natural gas resources such as shale gas, coalbed methane, and tight gas. However, foam fracturing fluid itself has high friction and low fluid column pressure, which limits its application in deep oil and gas hydraulic fracturing. In view of the above shortcomings, a self-generated foam fracturing fluid has been proposed at present. With the help of the gas spontaneously generated at the bottom of the well, the foam fracturing fluid is generated in the downhole and in the formation, avoiding the friction between the foam fracturing fluid and the wellbore string, ...

AI Technical Summary

Problems solved by technology

If the acidity is strong, the gas will be generated quickly, so the quality of the foam produced will be high, and the formed foam fracturing fluid will easily carry the proppant into the formation, but the strong acidity will also cause corrosion to the pipe string, causing safety hazards

If the acidity is weak, the corrosion of the pipe string will be weakened, but the gas generation is slow, and the foam is not easy to generate, so the proppant cannot be carried, and it is easy to cause sand plugging near the wellbore

At the same time, in the process of self-gas generation, hydrogen ions will be consumed, the acidity will be weakened, and the gas efficiency will slow down in the later stage, that is, the efficiency of foam generation will decrease

[0013] (2) For the selection of existing foam stabilizers, macromolecular polymers are mostly used as foam stabilizers, which will cause a lot of irreversible damage to low-porosity and low-permeability unconventional gas reservoirs such as shale gas and coalbed methane, seriously It will block the pores and greatly reduce the conductivity of hydraulic fractures

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