Clay Control Additive For Wellbore Fluids

Abstract

A clay control additive for wellbore fluids comprises a blended starch polymer solution comprising a quarternary amine-functionalized starch polymer. The polymer is preferably cationized to a degree of substitution of at least 0.30. The starches may be synthetic or blended from natural amylose cationic starches. In an embodiment, a further additive comprises cactus mucilage obtained from the Opuntia genus, which may be combined with the starch polymer in a 1 to 95% solution. In another embodiment, both the starch and the mucilage may be further combined with conventional additives (e.g., choline chloride) to further enhance the clay control properties.

Dependencies are inferred from the claim text.