摘要
为了研究不同酸液体系在碳酸盐岩油藏酸压裂缝中指进的机理,利用研制的可视化酸液指进模拟试验装置,模拟酸压工况对不同注酸排量、不同压裂液/酸液黏度比、不同酸液浓度下酸液指进效果进行了评价。试验结果表明,整体上胶凝酸指进形态为根型,冻胶酸黏度高不会产生指进现象;重力、压裂液与酸液黏度比是决定指进形态的重要因素,重力影响酸液指进形态明显上向下发展,黏度比越大指进特征越明显;施工排量变化对酸液指进形态影响不大;随着酸液浓度增加,酸岩反应产生的CO_2越多,对酸液指进形态具有一定的破坏作用。采用低黏度的胶凝酸和大排量施工有利于酸液指进,依据实验优化结果制定了X井酸压施工方案,压后产能较常规工艺酸压井提高2倍,增产效果明显。
To study the fingering principle of different acid systems in acidizing-produced fractures of carbonate reservoirs,an observable acid fingering simulation test apparatus was used to evaluate the fingering conditions during acidizing at different acid flooding displacements,frac fluid viscosity/acid viscosity ratios,and acid concentrations. The results suggest that generally the gelled acid fingering is in a root shape,the cross-linked acid is too sticky to finger. Gravity and fracturing fluid viscosity/acid viscosity ratio are the key factors deciding fingering pattern.Gravity tends to lead the fingering downwards,and the fingering is more obvious with the increase of the viscosity ratio. The acid rate has minimal influence on fingering pattern. The increase in the acid concentration will increase CO_2 produced during acidrock reaction,causing some destruction to fingering pattern. Injecting low-viscosity gelled acid at high rates is beneficial for fingering. The acidizing program for Well XX was optimized according to the study results,the production after acidizing has been 2 times higher than that with conventional technology,the production increase is remarkable.
出处
《钻采工艺》
北大核心
2017年第4期50-52,共3页
Drilling & Production Technology
基金
国家"十二五"科技重大专项"缝洞型碳酸盐岩油藏高效酸压改造技术"(2011ZX05014-006)资助
关键词
酸液
指进
可视化
acid fluid
fingering
visualization
