Self-suspending proppants for hydraulic fracturing
AssigneeSelf-Suspending Proppant LLC
InventorsRobert P. Mahoney, David S. Soane, Marie K. Herring, Kevin P. Kincaid, Rosa Casado Portilla, Philip Wuthridge
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Abstract
The invention provides for modified proppants, comprising a proppant particle and a hydrogel coating, wherein the hydrogel coating localizes on the surface of the proppant particle to produce the modified proppant, methods of manufacturing such proppants and methods of use.
Claims25
A modified proppant comprising a proppant particle substrate and a coating of a hydrogel-forming polymer, wherein the coating localizes on the surfaces of the proppant particle substrate to produce the modified proppant,
- wherein the coating comprises a hydrogel-forming polymer having a weight average molecular weight of≧about 1 million g/mol,
- wherein the hydrogel-forming polymer forms a substantially continuous film on the surface of the proppant particle which is crosslinked,
- wherein swelling of the hydrogel-forming polymer to increase the buoyancy of the modified proppant is essentially complete within 10 minutes of being combined with an aqueous fracturing fluid,
- wherein 1 gram of the modified proppant when mixed with water in a 20 ml glass vial for about 1 minute and then allowed to sit undisturbed until the hydrogel-polymer has been hydrated exhibits an expanded settled bed height which is about 1.5 to about 28 times greater than the settled bed height of an otherwise identical proppant not modified with a hydrogel coating, and
- wherein the modified proppant exhibits a shearing ratio of≧0.2 when measured by the Shear Analytical Test described in the specification.
A modified proppant for combining with an aqueous fracturing fluid, the modified proppant comprising a proppant particle substrate and a coating of a hydrogel-forming polymer, wherein the coating localizes on the surfaces of the proppant particle substrate to produce the modified proppant, wherein the coating comprises a hydrogel-forming polymer having a weight average molecular weight of≧about 1 million g/mol, wherein the hydrogel-forming polymer forms a substantially continuous film on the surface of the proppant particle which is crosslinked, wherein the hydrogel-forming polymer is selected so that when 1 to 3 grams of the dried modified proppant is added to 100 ml of tap water in a 100 ml graduated cylinder and then inverted 8 times, the modified proppant exhibits a settling time which is about 2 (22/10) to 7 (71/10) times the settling time of the proppant substrate particle, and wherein the modified proppant exhibits a shearing ratio of≧0.2 when measured by the Shear Analytical Test described in the specification.
Dependencies are inferred from the claim text.