Method of gravel packing a well

A method for gravel packing a subterranean formation penetrated by a well bore comprising:

• preparing a gravel packing fluid by admixing an aqueous liquid, a gelling agent comprising a cellulose ether which is chemically modified to incorporate pendent vicinal dihydroxy groups in an amount sufficient to provide a DS of about 0.3 to about 1.3 and exhibits shear-thermal stability at a temperature in excess of 200.degree. F., said gelling agent being present in an amount in excess of about 0.2 percent by weight of said aqueous liquid, a crosslinking agent comprising a compound containing soluble zirconium IV ions present in an amount of at least about 0.001 percent by weight of said aqueous liquid and a particulate agent, said gelling agent being prepared by charging said cellulose ether to a diluent system including water in an amount sufficient to swell said cellulose ether to provide a slurry in an enclosed reaction vessel, adding an alkaline material in an amount sufficient to catalyze the reaction of said cellulose ether, with a reactant capable of incorporating into said cellulose ether a pendent vicinal dihydroxy structure, adding said reactant over a predetermined period of time in an amount sufficient to react with and incorporate in said cellulose ether said degree of substitution of pendent vicinal dihydroxy structure, maintaining the temperature of said slurry of cellulose ether and said reactant at a temperature in the range of from about ambient to about the reflux temperature of the diluent system during said reaction, adding acid in an amount sufficient to neutralize the modified cellulose ether to form a water soluble cellulose ether product comprising said gelling agent;
• introducing said gravel packing fluid into a subterranean formation through said highly deviated well bore;
• and
• depositing said particulate agent within said well bore to form a permeable pack.

A method for gravel packing a highly deviated well bore penetrating a subterranean formation comprising:

• preparing a gelled gravel packing fluid by admixing an aqueous liquid, a gelling agent comprising a cellulose ether which is chemically modified to incorporate pendent vicinal dihydroxy groups in an amount sufficient to provide a DS of about 0.3 to about 1.3 and exhibits shear-thermal stability at a temperature in excess of 200.degree. F., said gelling agent being present in an amount in excess of about 0.2 percent by weight of said aqueous liquid, a crosslinking agent comprising a zirconium IV-containing compound present in an amount of at least about 0.001 percent by weight of said aqueous liquid, a breaker present in an amount of at least about 0.1 pound per 1000 gallons of aqueous liquid and a particulate agent;
• introducing said gravel packing fluid into a subterranean formation through said highly deviated well bore;
• depositing said particulate agent within said well bore to form a permeable pack,
• breaking said gelled fluid to a viscosity similar to that of water;
• and,
• applying pressure through said broken fluid to said deposited particulate agent to compact said permeable pack to minimize void spaces therein.