【摘要】 酸压中,严重的酸液滤失是限制裂缝扩展和酸液作用距离的主要因素.针对天然裂缝发育的碳酸盐岩储层特征,综合考虑酸岩反应,裂缝表面溶蚀导致的缝宽变化,流体在天然裂缝地层的流动,建立了裂缝型碳酸盐岩气藏酸压滤失计算模型.结果显示:与不考虑酸岩反应相比,考虑酸岩反应后的酸液滤失量是非反应性液体滤失量的4倍;酸液由于酸扩大了天然裂缝,滤失速度随时间先增加后降低,而非反应性液体的滤失速度不断下降;主裂缝(宽度>10μm)主导滤失,微裂缝(宽度<5μm)对滤失贡献与主裂缝相比可以忽略.该模型解释了在天然裂缝地层酸液滤失的机理,提供了一种更准确计算滤失量的方法.更多还原

【Abstract】 In acid fracturing,serious acid leakoff is the main factor limiting fracture propagation and the acid penetration distance.To research the leakoff effect on the natural fracture carbonate formation,a numerical model combining the acid rock reaction,fracture width variation,natural fracture reservoir fluid flow was established.In the study,it could be found that the total amount of acid leakoff is 4times than that of reactive liquid.And the leakoff rate increases firstly,and then reduces over time,while the continuous falling that of the non-reactive liquid falls continuously.Main fracture width(>10μm)leads filtration and micro-fracture width(<5μm)can be ignored.The study explains the mechanism of acid leakoff in natural fracture formation,providing a more accurate method to calculate the amount of leakoff.更多还原