塔北与巴楚下丘里塔格群白云岩储层特征对比

Comparison of Dolomite Reservoir Characteristics Between the Northern Tarim Basin and Lower Qiulitage Group of Bachu

彭军 曹俊娇 李斌 夏青松 刘昕羽

PENG Jun CAO Junjiao LI Bin XIA Qingsong LIU Xinyu

西南石油大学地球科学与技术学院, 四川 成都 610500

School of Geosciences and Technology, Southwest Petroleum University, Chengdu, Sichuan 610500, China

针对塔北和巴楚地区下丘里塔格群白云岩储层特征的差异问题，通过岩芯描述、薄片鉴定、阴极发光、扫描电镜、物性分析以及压汞等资料从岩石学、储集空间、物性及孔隙结构几个方面进行研究。结果表明：塔北地区主要为晶粒白云岩和颗粒白云岩；储集空间以晶间孔、晶间溶孔、溶蚀孔洞和裂缝为主，储集空间类型组合多样；喉道主要为粗-细喉型，分选好，孔喉分布均匀，连通性较好，物性较好；此外该区构造破裂作用和岩溶作用发育，也改善了储层物性。巴楚地区以晶粒白云岩和泥微晶白云岩为主；溶蚀孔洞、裂缝的发育程度和规模不如塔北地区，储集空间类型组合较单一；喉道多为细-微喉型，分选差，孔喉分布极不均匀，连通性差，物性较差。塔北地区白云岩储层物性好于巴楚地区，造成该差异的原因主要是受到了沉积作用和成岩作用的共同影响。

This study investigated differences in dolomite reservoir characteristics between the Northern Tarim Basin and the Lower Qiulitage Group of Bachu in terms of petrology, reservoir space, physical properties, porous structure, etc., through rock core description, rock thin section assessment, cathodoluminescence, scanning electron microscopy, physical property analysis, and mercury injection data. The results show that dolomite in the Northern Tarim Basin is mainly crystalline or granular. The reservoir space primarily comprises intercrystalline pores, intercrystalline dissolution pores, dissolution cavities, and fissures in various combinations. The pore throat is mainly of the coarse-fine type with good sorting and even distribution. The connectivity and physical properties are both good. Tectonic fractures and karstification also developed in this area, improving the physical properties of the reservoir. The Bachu area is dominated by crystalline dolomite and silty dolomicrite. The development and scope of dissolution cavities and fissures are much lower than in the Northern Tarim Basin, with less varied reservoir space combinations. The pore throat is mainly of the fine-micro type with poor sorting and uneven distribution. The connectivity and physical properties are also poor. The physical properties of the dolomite reservoir in Northern Tarim Basin are better than that in the Bachu area. This difference is mainly caused by the combined effects of sedimentation and diagenesis.

10.11885/j.issn.1674-5086.2017.01.23.04