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US 5,551,515 AGranted
Hemicellulase active at extremes of Ph and temperature and utilizing the enzyme in oil wells
AssigneeChemgen Corporation
InventorsDouglas W. Fodge, David M. Anderson, Thomas M. Pettey
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Abstract
Soil bacteria can be isolated which produce an enzyme capable of catalyzing the degradation of mannan-containing hemicellulose under conditions combining high pH and high temperature. Such bacteria can be cultured or used as sources of genetic information with which to engineer other microorganisms to produce the enzyme. Commercially useful quantities of native or recombinant hemicellulase can thus be produced by cultures consisting essentially of microorganisms capable of producing the enzyme.
Claims2
A method of conditioning subterranean oil wells comprising the steps of
- (a) preparing a suspension comprised of water, a hydraulic gelling agent and a proppant, said proppant having an indicated mesh size;
- (b) pumping an adequate amount of said suspension under high pressure into an oil well causing a fracture to occur in subterranean geologic formations adjacent to said well such that said suspension is deposited in said fracture;
- and
- (c) pumping an adequate amount of an enzyme endo-.beta.-mannanase enzyme that catalyzes the degradation of mannan, wherein said enzyme (i) has a pH profile for endo-.beta.-mannanase activity with the substrate guar that ranges from pH 4.5 to pH 11, and (ii) retains 50% of its maximum activity after 45 minutes at pH 9.0 and 75.degree. C. with the substrate guar into said fracture with said suspension to effect degradation of said hydraulic gelling agent.
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Dependencies are inferred from the claim text.