微生物结构对微生物白云岩孔隙特征的影响——以塔里木盆地柯坪地区肖尔布拉克组为例

Influence of microbial textures on pore characteristics of microbial dolomites: A case study of Lower Cambrian Xiaoerbulake Formation in Keping area, Tarim Basin

余浩元 蔡春芳 郑剑锋 黄理力 袁文芳

YU Haoyuan CAI Chunfang ZHENG Jianfeng HUANG Lili YUAN Wenfang

中国科学院 地质与地球物理研究所, 中国科学院油气资源研究重点实验室, 北京 100029 2. 中国科学院大学 地球科学学院, 北京 100049 3. 中国科学院 地球科学研究院, 北京 100029 4. 中国石油杭州地质研究院, 杭州 310023 5. 中国石油天然气集团公司 碳酸盐岩储层重点实验室, 杭州 310023 6. 中国石油 塔里木油田分公司 勘探开发研究院, 新疆 库尔勒 841000

Key Laboratory of Petroleum Resources Research, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China 2. College of Earth Sciences, University of Chinese Academy of Sciences, Beijing 100049, China 3. Institutions of Earth Science, Chinese Academy of Sciences, Beijing 100029, China 4. PetroChina Hangzhou Institute of Petroleum Geology, Hangzhou, Zhejiang 310023, China 5. Key Laboratory of Carbonate Reservoirs, CNPC, Hangzhou, Zhejiang 310023, China 6. Institute of Exploration and Development, Tarim Oil Field, PetroChina, Korla, Xinjiang 841000, China

微生物结构是微生物白云岩区别于常规碳酸盐岩的重要特征，研究微生物结构与孔隙特征的关系是研究微生物白云岩储层成因和分布的关键。以塔里木盆地西北缘柯坪地区典型野外剖面肖尔布拉克组为例，选取凝块石白云岩、泡沫绵层石白云岩、叠层石白云岩及泥粉晶白云岩样品，通过实验测试表征其物性特征和孔隙结构特征，并与相应的微生物结构相关联，以分析微生物结构对孔隙特征的影响。根据成岩改造强度和性质的不同将样品分为3组，对比其孔隙特征来分析成岩作用的改造。结果显示，微生物结构与孔隙特征关系密切，沉积作用通过控制微生物结构来控制微生物白云岩的孔隙特征，而成岩作用则主要在沉积作用的基础上进行叠加改造，并受微生物结构的制约。

Microbial texture is an important characteristic of microbial dolomites compared to conventional carbonate rocks. Thus, studying microbial texture is the key to understand the origin and distribution of microbial dolomites. We selected thrombolite dolomite, foam spongy dolomite and stromatolite dolomite samples of the Xiaoerbulake Formation in Keping area in the northwestern Tarim Basin to test their petrophysical properties and pore structures. The test results were correlated with corresponding microbial textures to analyze their influence on pore characteristics. These samples were divided into three groups with different intensities of diagenesis alteration in order to analyze its effects. The results showed that the pore structures of microbial dolomites were closely related to their microbial textures. Sedimentation served as the dominating factor of pore structures with its controls on microbial textures, while diagenesis, under the restriction of microbial textures, changed the pore system mainly on the basis of sedimentation.

国家科技重大专项（2017ZX05008-003-040）资助。

https://doi.org/10.11781/sysydz201802233