酸蚀裂缝导流能力实验结果新应用

根据API行业标准,利用酸蚀裂缝导流装置开展了冻胶酸裂缝导流能力的测试,计算溶蚀速率来推导酸岩反应速率,并根据酸蚀前后导流能力计算残酸浓度,比传统的残酸浓度更精确,应用反应速率与残酸浓度值计算酸液有效作用距离。实验结果表明冻胶酸残酸浓度随着闭合应力的增大而增大,闭合应力越大越早失去效果,鲜酸浓度越高,残酸浓度越高。此法既能更精确预测酸液有效作用距离又能评价酸蚀导流能力,是一种经济适用的酸蚀效果评价方法。

New application in Experimental Results of Acid-Etched Fracture Conductivity

According to API industrial standard, this paper uses acid-etched fracture conductivity measurement device to conduct conductivity experiments with cross-linked acids, and deviated acid-reaction rates according to calculated rock dissolved rates, then calculates spent acid concentrations through fracture conductivities before and after acidizing. The spent acid concentrations obtained in this paper are more accurate than those from conventional method. Finally, combined acid-reaction rates and spent acid concentrations, this paper calculated acid effective reaction distance. Results show that spent acid concentration raises with increasing of closure stress; the bigger the closure stress is, the earlier the acid becomes spent acid; the higher fresh acid concentration is, the higher spent acid concentration will be. The new calculating method in this paper can predict acid effective reaction distance more accurately and evaluate acid-etched fracture conductivity, so it is an economical way to evaluate acidizing effect.