Treatment fluids for acid diversion during acid stimulation of a subterranean formation may include at least an acidizing fluid, a nanoparticle dispersion, and an activator. The treatment fluid may include from 40 weight percent to 70 weight percent acidizing fluid based on the total weight of the treatment fluid. The treatment fluid may include from 20 weight percent to 40 weight percent nanoparticle dispersion based on the total weight of the treatment fluid. The treatment fluid may include from 5 weight percent to 15 percent activator based on the total weight of the treatment fluid. Methods of treating a subterranean formation with the treatment fluids are also disclosed.

Treatment fluids for acid diversion during acid stimulation of a subterranean formation may include at least an acidizing fluid, a nanoparticle dispersion, and an activator. The treatment fluid may include from 40 weight percent to 70 weight percent acidizing fluid based on the total weight of the treatment fluid. The treatment fluid may include from 20 weight percent to 40 weight percent nanoparticle dispersion based on the total weight of the treatment fluid. The treatment fluid may include from 5 weight percent to 15 percent activator based on the total weight of the treatment fluid. Methods of treating a subterranean formation with the treatment fluids are also disclosed.

Treatment fluids for acid diversion during acid stimulation of a subterranean formation may include at least an acidizing fluid, a nanoparticle dispersion, and an activator. The treatment fluid may include from 40 weight percent to 70 weight percent acidizing fluid based on the total weight of the treatment fluid. The treatment fluid may include from 20 weight percent to 40 weight percent nanoparticle dispersion based on the total weight of the treatment fluid. The treatment fluid may include from 5 weight percent to 15 percent activator based on the total weight of the treatment fluid. Methods of treating a subterranean formation with the treatment fluids are also disclosed.

A method for the preparation of a scale inhibitor and a method of inhibiting the formation of scale uses a water soluble polymeric gelling agent, in particular synthetic polymer, which has been degraded and reduced in its molecular weight.

Sandstone formations of oil and gas and geothermal wells may be successfully stimulated with a fluid containing GLDA or salt and HF or a HF-generating component and an organophosphonate component. The organophosphonate acts as a sequestering agent and reduces the amount of metal fluoride precipitates produced.

Process for making a chelating agent according to the general formula (I),

R.sup.1CH(COOX.sup.1)N(CH.sub.2COOX.sup.1).sub.2(I)

wherein R.sup.1 is selected from hydrogen, C.sub.1-C.sub.4-alkyl, phenyl, benzyl, CH.sub.2OH, and CH.sub.2CH.sub.2COOX.sup.1, X.sup.1 is (M.sub.xH.sub.1-x), M being selected from alkali metal, x is in the range of from 0.6 to 1, said process comprising the following steps: (a) providing a solid, a slurry or a solution of a compound according to general formula (II a)

R.sup.1CH(COOX.sup.2)N(CH.sub.2CN).sub.2(II a) wherein X.sup.2 is (M.sub.yH.sub.1-y), M being selected from alkali metal, y is in the range of from zero to 1, (b) contacting said solid or slurry or solution with an aqueous solution of alkali metal hydroxide, wherein the molar ratio of alkali metal ions to nitrile groups is in the range of from 0.6:1 to 0.95:1, (c) reacting said compound according to general formula (II a) with said alkali metal hydroxide.

Process for making a chelating agent according to the general formula (I), R.sup.1CH(COOX.sup.1)N(CH2COOX.sup.1).sub.2 wherein R.sup.1 is selected from hydrogen, C.sub.1-C.sub.4-alkyl, phenyl, benzyl, CH.sub.2OH, and CH.sub.2CH.sub.2COOX.sup.1, X.sup.1 is (M.sub.H.sub.1), M being selected from alkali metal, x is in the range of from 0.6 to 1, said process comprising the following steps: (a) providing a solid, a slurry or a solution of a compound according to general formula (II a) R.sup.1CH(COOX.sup.2)N(CH.sub.2CN).sub.2 wherein X.sup.2 is (M.sub.yH.sub.1y), M being selected from alkali metal, y is in the range of from zero to 1, (b) contacting said solid or slurry or solution with an aqueous solution of alkali metal hydroxide, wherein the molar ratio of alkali metal ions to nitrile groups is in the range of from 0.6:1 to 0.95:1, (c) reacting said compound according to general formula (II a) with said alkali metal hydroxide.

A process is disclosed that includes providing a mixture to a wellbore. The mixture can comprise formic acid or a formic acid precursor, a salt of lactic acid, and a salt of gluconic acid. The mixture can be introduced into an underground formation around the wellbore. The mixture can prevent or at least reduce the formation of formate crystals as compared to mixtures without the salt of lactic acid or the salt of gluconic acid. The mixture permits the formic acid, or formic acid produced from hydrolysis of the formic acid precursor, to react with acid soluble material in the underground formation to generate soluble calcium salts.

Process for making a chelating agent according to the general formula (I), R.sup.1CH(COOX.sup.1)N(CH2COOX.sup.1).sub.2 wherein R.sup.1 is selected from hydrogen, C.sub.1-C.sub.4-alkyl, phenyl, benzyl, CH.sub.2OH, and CH.sub.2CH.sub.2COOX.sup.1, X.sup.1 is (M.sub.H.sub.1-), M being selected from alkali metal, x is in the range of from 0.6 to 1, said process comprising the following steps: (a) providing a solid, a slurry or a solution of a compound according to general formula (II a) R.sup.1CH(COOX.sup.2)N(CH.sub.2CN).sub.2 wherein X.sup.2 is (M.sub.yH.sub.1-y), M being selected from alkali metal, y is in the range of from zero to 1, (b) contacting said solid or slurry or solution with an aqueous solution of alkali metal hydroxide, wherein the molar ratio of alkali metal ions to nitrile groups is in the range of from 0.6:1 to 0.95:1, (c) reacting said compound according to general formula (II a) with said alkali metal hydroxide.

Remediation of a hydrocarbon producing well bore in a subterranean formation includes injecting fluid containing self-degrading particulates into the well bore in order to stop production of hydrocarbon from the well bore prior to commencement of remedial operations and to temporarily seal the well bore from fluid transmission between the well bore and the formation prior to commencement of the remedial operations, and commencing the remedial operations upon the well bore. Examples of the remedial operations include injecting weighted fluid into the well bore, inserting a down-hole tool into the well bore, casing treatment, annulus treatment, well bore wall treatment, cementing, and refracturing. For refracturing, the fluid containing the self-degrading particulates can be injected until a down-hole pressure exceeds a fracture breakdown pressure of new fractures that will be produced by a perforating tool lowered into the well bore.