Method for fracturing a subterranean geological formation with an emulsified acid
AssigneeKing Fahd University of Petroleum and Minerals
InventorsAbdullah S. Sultan, Ziad Sidaoui
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Abstract
A method of acidizing a subterranean geological formation by injecting an emulsified acid into a wellbore, wherein the emulsified acid includes at least an aqueous phase comprising a hydrochloric acid solution, an oil phase comprising waste oil, and an emulsifier, and wherein the waste oil contains 45-75% by weight of aromatic compounds and preferably contains less than 0.5% by weight of non-hydrocarbon compounds. Various embodiments, and combinations of embodiments, of the emulsified acid and the method of acidizing are provided.
Claims8
A method of acidizing and fracturing a subterranean geological formation surrounding a wellbore, comprising:
- injecting an emulsified acid into the wellbore to acidize the subterranean geological formation,
- acid fracturing the geological formation by injecting the emulsified acid into the wellbore at a pressure of 5,000-30,000 psi, wherein the injecting radially disperses the emulsified acid into the subterranean geological formation through an end of a capped coiled tubing disposed downhole in the wellbore;
- wherein the emulsified acid comprises
- 60-72% by volume of an aqueous phase comprising hydrochloric acid,
- 25-35% by volume of an oil phase comprising a waste oil, and
- 0.1-3.0% by volume of an emulsifier, relative to a total volume of the emulsified acid, and
- wherein the waste oil comprises 23-24% by weight paraffins, 9-10% by weight naphthenes, 18-20% by weight polynaphthenes, 18-20% by weight monoaromatics, 10-12% by weight naphthenomonoaromatics, 9-10% by weight diaromatics, 3-4% by weight naphthenodiaromatics, 2-3% by weight triaromatics, and 1-3% by weight naphthenotriaromatics, each relative to a total weight of the waste oil.
Dependencies are inferred from the claim text.