Gelling agent for water shut-off in oil and gas wells
OwnerShawqui M. Lahalihinventor
Life of this patent
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Abstract
The gelling agent for water shut-off in oil and gas wells is a composition that forms a gel to reduce or eliminate the flow of water in a gas or oil well. The composition is formed by mixing polyvinyl alcohol, a polyvinyl alcohol copolymer, or mixtures thereof with an amino-aldehyde oligomer, such as urea formaldehyde or melamine formaldehyde, with or without a cross-linker. The polymer composition can be used to minimize or completely shut off excess water production with insignificant reduction in hydrocarbon productivity.
Claims8
A gelling agent for water shut-off in oil and gas wells, comprising:
- a water soluble polymer selected from the group consisting of polyvinyl alcohol, a polyvinyl alcohol copolymer and mixtures thereof;
- an amino aldehyde oligomer selected from the group consisting of urea formaldehyde and melamine formaldehyde;
- at least one gelation retarder selected from the group consisting of lignosulfonates and ethyl acetate;
- a cross-linking agent selected from the group consisting of boric acid, acetic acid, borax, ammonium chloride, ammonium sulfate, glyoxal, and glutardialdehyde;
- and an aqueous solvent, the water soluble polymer and the amino aldehyde oligomer being mixed in the aqueous solvent to form a polymer solution, the water soluble polymer being between 10% and 50% by weight of the polymer solution, and the amino aldehyde oligomer being between 50% and 90% by weight of the polymer solution.
A gelling agent for water shut-off in oil and gas wells, comprising:
- a water soluble polymer selected from the group consisting of polyvinyl alcohol, a polyvinyl alcohol copolymer and mixtures thereof;
- an amino aldehyde oligomer selected from the group consisting of urea formaldehyde and melamine formaldehyde;
- at least one gelation accelerator selected from the group consisting of sulfonated melamine formaldehyde and sulfonated naphthalene formaldehyde;
- a cross-linking agent selected from the group consisting of boric acid, acetic acid, borax, ammonium chloride, ammonium sulfate, glyoxal, and glutardialdehyde;
- and
- an aqueous solvent, the water soluble polymer and the amino aldehyde oligomer being mixed in the aqueous solvent to form a polymer solution, the water soluble polymer being between 10% and 50% by weight of the polymer solution, and the amino aldehyde oligomer being between 50% and 90% by weight of the polymer solution.
A gelling agent for water shut-off in oil and gas wells, comprising:
- 10% to 50% by weight of polyvinyl alcohol;
- 50% to 90% by weight of urea formaldehyde;
- 0.0125% to 0.05% by weight acetic acid;
- and
- an aqueous solvent.
Dependencies are inferred from the claim text.