Fluid loss control system
AssigneeW. R. Grace & Co.
InventorJacob Block
Life of this patent
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Abstract
A composition capable of imparting fluid loss control properties to aqueous systems. The composition is an admixture of: (a) a solid particulate material having a particle size distribution wherein at least about 90% of said material is capable of passing through a No. 20 U.S. Standard (Fine Series) Sieve; and (b) a cross-linked hydroxyalkyl cellulose; wherein the amount of component (a) to component (b) is in the weight ratio of at least about 0.5. The invention is further directed to improved drilling fluids containing said composition and to the process of drilling bore holes using said improved fluid.
Claims10
A composition capable of imparting fluid loss control to aqueous systems, said composition comprising a mixture of:
- (a) a solid, particulate material which is insoluble in the aqueous system and having a particle size wherein at least about 90% of said material is capable of passing through a No. 20 U.S. Standard Sieve;
- and
- (b) a reaction product formed in an aqueous solution of a water soluble hydroxy C.sub.1 -C.sub.3 alkyl cellulose between said hydroxyalkyl cellulose and from at least about 1 to 200 percent of stoichiometry based on the hydroxyl groups of the cellulose of an agent capable of cross-linking said cellulose selected from the group consisting of an epihalohydrin, a compound having at least one aldehyde group therein or a compound capable of generating an aldehyde group in situ;
- component (a) and (b) being present in a ratio of at least 0.5:1 to 3:1;
- the reaction between said hydroxyalkyl cellulose and a compound having or capable of generating at least one aldehyde group therein is carried out in an aqueous acidic medium having a pH of 5.5 or less and the reaction between said hydroxyalkyl cellulose and an epihalohydrin is carried out in an aqueous basic medium having a pH of at least about 9.
Dependencies are inferred from the claim text.