Patent ID: 7622427

Claim:
A completion and workover fluid composition comprising water and at least one rheology modifier and/or fluid loss control agent, and at least one other ingredient selected from the group consisting of polymeric additive, inorganic salts, shale stabilizers, corrosion inhibitors, weighting agents, and finely divided clay particles wherein the rheology modifier and/or the fluid loss control agent is ethoxylated raw cotton linters (EO-RCL), wherein the EO-RCL has an oxyethylene molar substitution (MS) with a lower limit of about 0.5 and wherein the at least one other ingredient comprises an inorganic salt and wherein the inorganic salt is selected from the group consisting of calcium carbonate, calcium chloride, potassium chloride, sodium chloride, magnesium chloride, sodium bromide, potassium bromide, calcium bromide, zinc bromide, sodium formate, potassium formate, cesium formate and mixtures thereof.