Use of composites having coating of reaction product of silicates and polyacrylic acid
AssigneeBaker Hughes Holdings LLC
InventorsThomas Sodhi, D. V. Satyanarayana Gupta, John Howard Mayor
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Abstract
The strength of a proppant or sand control particulate may be improved by coating the proppant to form a composite. The composite has enhanced compressive strength between about 34 to about 130 MPa and minimizes the spelling of fines at closure stresses in excess of 5,000 psi. Conductivity of fractures is further enhanced by forming a pack of the composites in the fracture.
Claims26
A method of hydraulic fracturing a subterranean formation penetrated by a well comprising pumping into the well a proppant and creating or enlarging a fracture within the subterranean formation, wherein the proppant is a composite comprising a core wherein at least a portion of the surface of the core is coated with a reaction product of sodium silicate and a polyacrylic acid catalyzed in the presence of calcium chloride or zinc chloride and further wherein the weight average molecular weight of the polyacrylic acid is between from about 1,000 to about 4,000.
A method of hydraulic fracturing a subterranean formation penetrated by well comprising pumping into the well a proppant and creating or enlarging a fracture within the subterranean formation, wherein (i) the proppant is a composite comprising a core wherein at least a portion of the surface of the core is coated with a reaction product of sodium silicate and a polyacrylic acid catalyzed in the presence of calcium chloride or zinc chloride wherein the polyacrylic acid has a weight average molecular weight between from about 1,000 to about 4,000;
- (ii) the core is selected from the group consisting of sand, ceramic beads, glass beads, bauxite grains, sintered bauxite, sized calcium carbonate, walnut shell fragments, aluminum pellets, silica, nylon pellets, nut shells, gravel, resinous particles, alumina, minerals, polymeric particles, and combinations thereof;
- and (iii) the composite withstands a closure stress up to about 12,000 psi when the coating ranges from about 3 to about 20 wt. percent of the weight of the core.
A method of hydraulic fracturing a subterranean formation penetrated by a well comprising pumping into the well a proppant and creating or enlarging a fracture within the subterranean formation, wherein the proppant is a composite comprising a core encapsulated by a coating comprising the reaction product of sodium silicate and a polyacrylic acid catalyzed in the presence of calcium chloride or zinc chloride and further wherein the weight average molecular weight of the polyacrylic acid is between from about 1,000 to about 4,000 and the thickness of the coating is between from about 2 to about 120 microns.
Dependencies are inferred from the claim text.