Abstract: A method of reclaiming a well completion brine solution by using an organic chelant that is capable of discriminating between (i) iron and non-zinc heavy metals; and (ii) calcium and zinc. The chelant contains a functional group selected from the group —CO2H or —PO(OH)R20 or a salt or ester thereof, —C(O)—, —OE, —SE, —N?C(R2)R3, EO—N?C(R2)R3, —N(R2)R3, and —N(C(O)R1)R2 group optionally substituted with a —COOH or —PO(OH)R20 or a salt or ester thereof, —SE or —OE group, wherein R2 and R3 are independently selected from E or forms, with nitrogen, phosphorous, oxygen or sulfur, a heterocyclic ring; E is R1 or —H; R1 is a C1-C30 alkyl or aralkyl group or a derivative thereof and R20 is —OH or R1.

Abstract: A well treating composition contains an aqueous acid and at least one relatively lightweight proppant, preferably having an apparent specific gravity (ASG) less than or equal to 2.45. The acid fracturing composition may used to acid fracture a hydrocarbon reservoir within a subterranean formation of an oil or gas well. The composition may further be used to stimulate the production of hydrocarbons. The proportion of relatively lightweight proppant to acid in the composition is such that the dimensional fracture conductivity (CfD) is in excess of 1.0. The aqueous acid typically has an ASG substantially equal to the ASG of the relatively lightweight particulate. As such, the relatively lightweight particulate is suspended in the aqueous acid.

Abstract: A method for removing or dissolving calcareous materials in a subterranean formation or in a wellbore consists of two basic steps. In the first step, an aqueous acid solution is injected into the formation or wellbore. The aqueous acid solution contains between from about 15 to about 99 weight percent of an organic acid selected from formic acid, acetic acid or a mixture of formic acid and acetic acid. Water or brine is then injected into the formation or wellbore. The amount of water or brine injected into the formation or wellbore is an amount sufficient to reduce the concentration of organic acid in the formation or wellbore to no greater than 10 weight percent.

Abstract: A method of reclaiming a well completion brine solution by using an organic chelant that is capable of discriminating between (i) iron and non-zinc heavy metals; and (ii) calcium and zinc. The chelant contains a functional group selected from the group —CO2H or —PO(OH)R20 or a salt or ester thereof, —C(O)—, —OE, —SE, —N?C(R2)R3, EO—N?C(R2)R3, —N(R2)R3, and —N(C(O)R1)R2 group optionally substituted with a —COOH or —PO(OH)R20 or a salt or ester thereof, —SE or —OE group, wherein R2 and R3 are independently selected from E or forms, with nitrogen, phosphorous, oxygen or sulfur, a heterocyclic ring; E is R1 or —H; R1 is a C1-C30 alkyl or aralkyl group or a derivative thereof and R20 is —OH or R1.