酸化前后碳酸盐岩微细观组构及力学性能研究  

Study on the Microstructure and Mechanical Properties of Carbonate Rock before and after Acidification

作　　者：刘厚彬[1] 崔帅 孟英峰[1] 朱达江 李玉飞 Liu Houbin;Cui Shuai;Meng Yingfeng;Zhu Dajiang;Li Yufei(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu 610500,P.R.China;Institute of Engineering Technology,PetroChina Southwest Oil and Gasfield Company,Chengdu 610017,P.R.China)

机构地区：[1]西南石油大学油气藏地质及开发工程国家重点实验室,成都610500 [2]中国石油西南油气田公司工程技术研究院,成都610017

出　　处：《地下空间与工程学报》2020年第5期1321-1327,1434,共8页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金(51134004,51204142)。

摘　　要：针对栖霞组储层裸眼酸压完井后发生的井壁出砂等情况,开展了栖霞组碳酸盐岩酸化前后微细观组构及力学性能的实验研究。研究结果表明:栖霞组储层主要以白云石、方解石为主;酸化作用对碳酸盐岩声波速度影响明显,裂缝发育加快酸液对测试岩样的腐蚀速度;酸化作用对岩心的孔渗参数影响明显,初期孔隙度增加快,后期增加速度降低,不同酸化阶段岩石渗透率变化规律存在差异;酸化作用对碳酸盐岩微细观结构影响明显,酸蚀作用主要集中在2 h以内导致岩体孔洞、裂缝尺寸明显增大;酸化效应对力学性能参数影响明显,岩样浸泡2 h其力学参数降低幅度最大,后期力学参数降低幅度变小,泊松比整体变化规律不明显。Given the situation of sand production in the borehole after completion of open-hole acidizing fracturing in Qixia formation reservoir,the microstructure and mechanical properties of Qixia formation carbonate rocks before and after acidification were studied through the laboratory experiments. The experimental result shows that the rock samples of Qixia formation are mainly composed of dolomite and calcite. The acoustic velocity of carbonate rock is significantly affected by acidification,the development of fracture accelerates the corrosion rate of acid solution. The effect of acidification on the pore-permeability parameters is obvious,and the porosity increases rapidly at the initial stage and increases slowly at the later stage. The change of rock permeability varies in different acidification stages. The effect of acid corrosion on the microstructure of carbonate rocks is obvious,and acid corrosion mainly concentrates in 2 hours,resulting in an obvious increase in the size of holes and cracks in the rock mass. The effect of acidification on mechanical properties is obvious. The maximum reduction of mechanical parameters was achieved after 2 hours of acid immersion,and the decreasing amplitude of mechanical parameters becomes smaller in the later period. The Poisson ratio change rule is not obvious for the acid immersion effect. The results provide a theoretical basis for the stability analysis of the carbonate reservoir after acidification.

关 键 词：碳酸盐岩 酸化 微细观结构 理化性能 力学参数 

分 类 号：TE121[石油与天然气工程—油气勘探]