| 摘要 |
A viscosifying additive composition for a drilling fluid, a completion fluid, a fracturing fluid, an injection fluid or combinations thereof, the composition comprising a first anionic polysaccharide polymer derived from kelp, preferably an alginate, and at least one breaker agent. The polymer chains may be crosslinked using glutaraldehyde or various metal ions. The breaker agent may be selected from an enzyme, a B vitamin, an oxidiser, an acid or combinations thereof. According to a further aspect, a breaker additive composition with at least two breaker agents is provided, wherein one of the breaker agents is a B vitamin, preferably B1 (thiamine), B2 (riboflavin) or B12 (cobalamin), another breaker agent being an enzyme, oxidiser or acid. The breaker additive may further have solid particles, the B vitamin being attached thereto. A viscosified well treatment fluid comprising an anionic polysaccharide polymer derived from kelp but not including a viscoelastic surfactant (VES) is also claimed. Finally, the invention also relates to a method wherein a viscosified fluid composition comprising a polymer derived from kelp is circulated into a subterranean reservoir. |
