普光气田多级交替注入闭合酸压技术及其应用

Multistage alternating injection closed acid fracturing technology and its applications in Puguang gas field

由于普光气田飞仙关组、长兴组碳酸盐岩储层具有高温、高压、岩性致密、非均质性强和天然裂缝发育等特点,常规酸压技术难以实现酸压深度改造。为此,在分析普光气田储层特点的基础上,建立了多级交替注入闭合酸压酸液指进程度评价模型,开展了针对多级交替注入闭合酸压技术影响因素的实验研究。结果表明:①交替注入的级数越多,酸蚀裂缝导流能力越高,但需要根据现场施工条件进行优化调整;②稠化酸作用后的酸蚀裂缝导流能力高于普通酸;③排量越大,裂缝的导流能力越高;④采用闭合酸压技术能够有效提高酸蚀裂缝导流能力。该技术在普光9井实施后,产气量由酸压前的10.32×104m3/d增至123.86×104m3/d,增产效果显著。截至2010年6月,对普光气田的5口新钻井实施多级交替注入闭合酸压投产,平均无阻流量高达621.8×104m3/d。

Due to characteristics of high temperature,high pressure,dense lithology,strong heterogeneity and natural fractures in carbonate reservoir of Feixianguan formation and Changxing formation in Puguang gas field,the adoption of conventional acid operation may result in quick acid rock reaction and large amount of fluid leak off,therefore,it is difficult to achieve the performance of acid fracturing.Based on Puguang gas field reservoir characteristics,we establish a calculating model of multistage alternating injection acid fracturing acid etching fracture conductivity and an evaluation model for the degree of acid fingering,and we carry out the experimental study of multistage alternating injection closed acid fracturing technique influencing factors.After application this technology in Puguang 9 well,gas production before acid fracturing is 10.32×104 m3/d and now increased to 123.86×104 m3/d,stimulating effect is significant.