塔里木盆地顺南地区中下奥陶统碳酸盐岩储层特征与主控因素

Characteristics and main controlling factors of carbonate reservoirs of Middle-Lower Ordovician, Shunnan area, Tarim Basin

刘军 陈强路 王鹏 尤东华 席斌斌 宫晗凝

LIU Jun CHEN Qianglu WANG Peng YOU Donghua XI Binbin GONG Hanning

中国石化 西北油田分公司 勘探开发研究院, 乌鲁木齐 830011 中国石化 石油勘探开发研究院 无锡石油地质研究所, 江苏 无锡 214126

Exploration and Development Research Institute, SINOPEC Northwest Oilfield Company, Urumqi, Xinjiang 830011, China Wuxi Research Institute of Petroleum Geology, SINOPEC, Wuxi, Jiangsu 214126, China

顺南地区位于塔里木盆地顺托果勒低隆的南部，目前已有多口井钻获天然气。随着勘探的推进，对储层发育规律的认识成为影响勘探评价的关键问题之一。在沉积相和构造演化背景研究的基础上，基于岩心描述、薄片鉴定、物性分析、综合录井和储层预测综合分析，对该区中下奥陶统储层进行了研究。中下奥陶统碳酸盐岩发育断控及热液改造的孔缝洞、白云岩晶间孔和晶间溶孔、灰岩颗粒内微孔隙等多尺度的储集空间，可划分为裂缝-孔隙型、断控缝洞型、热液改造孔缝洞型3种储层类型。裂缝-孔隙型分布于一间房组-鹰山组上段灰岩和鹰山组下段白云岩基质中，基质物性较差，为特低孔特低渗储层；断控缝洞型、热液改造孔缝洞型沿NE向走滑断裂带分布。多阶段发育的走滑断裂及伴生裂缝本身既可形成缝洞体储集空间，又沟通孔隙和微孔隙、晶间孔和晶间溶孔成为连通的有效储层，同时也是热液流体作用的先决条件，因而是规模有效储层的主控因素。

Natural gas breakthroughs have been made in many wells recently in the Shunnan in the southern part of the Shuntoguole low uplift in the Tarim Basin. With the advancement of exploration, the understanding of reservoir development is one of the key issues affecting exploration evaluation. Based on the research of sedimentary facies and tectonic evolution, core description, thin section analysis, physical property analysis, comprehensive logging and reservoir prediction were used to study the carbonate reservoirs in the Middle-Lower Ordovician in the study area. The reservoir spaces include pores and fractures controlled by fault and hydrothermal fluid activities, and also intercrystalline pores and intercrystalline solution pores in dolomite reservoirs, micropores in limestone reservoirs. There are three types of reservoirs, including fracture-cavity type controlled by faults, fracture-cavity type controlled by hydrothermal fluid activities, and fractures-pores. The fractures-pores mainly distribute in limestones in the Yijianfang Formation and the upper Yingshan Formation and in dolomites in the Lower Yingshan Formation. They have poor physical properties, and are featured by extra-low porosity and permeability. The fracture-cavity types controlled by faults and hydrothermal fluid activities mainly distribute along the NE strike-slip fault zone. Strike-slip fractures and associated fractures developed in multiple stages are the main controlling factors for large-scale effective reservoirs. They formed fractured-vuggy reservoirs. Meanwhile, they connected pores and micropores, intercrystalline pores, and intercrystalline dissolution pores, forming connected effective reservoirs, which was also a prerequisite for hydrothermal fluid activities.

中国石化科技部项目“塔里木盆地顺北-顺南地区奥陶系油气富集规律与目标评价” P18047

https://doi.org/10.11781/sysydz202101023