摘要 |
<p>The invention provides aqueous polysaccharide compositions comprising 0.03 to 5% w/v of a water-soluble polysaccharide, 5 to 80% w/v of at least one salt of at least one mono- or divalent cation, wherein at least 0.05% w/v, based on the composition, of the at least one salt is formate, the balance of the at least one salt, if any, being at least one halide, a process for preparing the compositions, and their use in well-drilling operations.</p> |