Method for stimulating well production

A method of increasing the production of fluids from a subterranean fluid-bearing formation having present therein acid-soluble components comprising injecting down the well bore penetrating said formation and injecting therefrom into said formation under a pressure greater than the formation pressure, an aqueous acidic solution containing from about 0.5 to about 28% by weight of a mineral acid having a compound therein in an amount of from about 0.005 to about 2% by weight, said compound being a water soluble sulfonated, ethoxylated compound having the general formula

• R(OCH.sub.2 CH.sub.2).sub.n SO.sub.3.sup.- A.sup.+
• wherein R is alkaryl, containing from about 6 to 18 carbon atoms in the alkyl portion thereof, n is a number from one to about 10, including fractions, and A.sup.+ is a monovalent cation selected from the group sodium, potassium, and ammonium, including mixtures, maintaining said solution in contact with the formation and production equipment for a time sufficient for the acid component to chemically react with the acid-soluble components of the formation to etch passageways therethrough thereby increasing substantially the flow capacity of the said subterranean formation and whereby said sulfonated, ethoxylated compound component is effective to prevent the formation of insoluble calcium compounds or the precipitation of calcium carbonate from the acid-spent solution.