酸性交联压裂液性能对比研究

对比研究了羧甲基胍胶和聚合物类酸性压裂液的性能,主要包括基液黏度、交联性能、携砂性能、破胶性能。研究表明:与聚合物基液相比,相同浓度下羧甲基胍胶基液的表观黏度及零剪切黏度更大;当pH值为5～6时,两者交联效果较佳,羧甲基冻胶黏度更大。采用Ostwald-Dewaele方程描述冻胶黏度与剪切速率的关系,并计算出交联冻胶的稠度系数。研究表明:羧甲基冻胶稠度系数明显大于聚合物稠度系数;在携砂性能方面,聚合物冻胶弹性模量更大,支撑剂沉降速度更小,携砂性能更好;在破胶性能方面,与羧甲基胍胶相比,聚合物冻胶破胶后残渣更低,对储层的伤害更小。

Comparative research on performances of acidic fracturing fluid

In this paper, the properties of carboxymethyl guar gum and polymer-based acidic fracturing fluids were compared, which include the viscosity of base fluid, cross-linking performance, sand-carrying performance and gel breaking performance. The results show that the apparent viscosity and zero shear viscosity of carboxymethyl guar gum base fluid are greater than polymer-based fluid at the same thickener concentration. At the pH value of 5-6, the cross-linking performances of them are better, and the viscosity of carboxymethyl gel is larger. The relationship between gel viscosity and shear rate could be described by Ostwald-Dewaele equation. Then the consistency coefficient of cross-linked gel was calculated. The result shows that the consistency coefficient of carboxymethyl gel is significantly larger than the polymer gel. In terms of sand carrying performance, the polymer gel has a larger elastic modulus, a smaller proppant settling rate, which shows better sand carrying performance. Forgel breaking performance, the residue of polymer gel was lower than that of the carboxymethyl fracturing fluid, which leads less damage to the reservoir.