复杂岩性碳酸盐岩裂缝型储层酸化压裂数值模拟  

Numerical simulation of acidizing fracturing in fractured carbonate reservoir with mixed lithology

作　　者：夏熙 牟建业[1,2] 张士诚[1,2] 卢盼盼 XIA Xi;MOU Jianye;ZHANG Shicheng;LU Panpan(College of Petroleum Engineering,China University of Petroleum(Beijing),Beijing 102249,China;State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(Beijing),Beijing 102249,China)

机构地区：[1]中国石油大学(北京)石油工程学院,北京102249 [2]中国石油大学(北京)油气资源与工程全国重点实验室,北京102249

出　　处：《大庆石油地质与开发》2024年第6期80-89,共10页Petroleum Geology & Oilfield Development in Daqing

基　　金：中国石化华北油气分公司项目“碳酸盐岩残酸伤害测试及盐下储层改造技术模拟”(34550139-20-FWO421-0017)。

摘　　要：鄂尔多斯盆地大牛地气田马家沟组碳酸盐岩储层岩性复杂,不同矿物成分的酸岩反应速率差异造成的非均匀溶蚀直接影响酸压效果。综合考虑多种矿物的酸岩反应,建立复杂岩性储层酸压模型,模拟分析了矿物含量、矿物分布、天然裂缝及储层温度等因素对酸压效果的影响。结果表明:由纯灰岩至复杂岩性储层,随着灰岩比例的减少,酸作用距离增加了23 m;岩矿分布对酸蚀缝长有较小影响,当酸液沿着矿物分布方向流动时酸作用距离最大;天然裂缝的发育加剧了酸液的滤失,裂缝密度相差0.2条/m时,酸作用距离减小约20 m;复杂岩性储层中温度影响最大,从60℃升至120℃时,白云岩酸岩反应速率接近灰岩,酸作用距离减小约72 m。研究成果为复杂岩性碳酸盐岩储层酸压改造提供了新方法,丰富了碳酸盐岩储层改造理论。The carbonate reservoir of Majiagou Formation in Daniudi Gas Field of Ordos Basin is characterized by mixed lithology,and acid-rock reaction rate varies much among different minerals.Considering comprehensively acid-rock reaction of various minerals,acid fracturing model of mixed lithology reservoir is established to simulate the influence of mineral content,mineral distribution,natural fractures and reservoir temperature on acidizing fracturing effect.The results show that acid penetration distance increases by 23 m with the decrease of limestone proportion from pure limestone to mixed lithology reservoir.Rock mineral distribution has little effect on acid penetrated fracture length,and acid penetration gets longest distance when acid flows along distribution direction of minerals.Natural fractures development increases acid leakoff.When fracture density difference is 0.2 fractures/m,acid penetration distance is reduced by about 20 m.Temperature has the most influence on mixed lithology reservoir.When reaction rate of dolomite is close to that of limestone from 60℃to 120℃,acid penetration distance decreases by 72 m.The research provides new method for acidizing fracturing stimulation of mixed lithology carbonate,and enriches the theory of carbonate reservoir stimulation.

关 键 词：酸压数值模拟 复杂岩性 碳酸盐岩 矿物含量 矿物分布 天然裂缝 温度 酸液作用距离 马家沟组 

分 类 号：TE357.2[石油与天然气工程—油气田开发工程]