塔里木盆地雅克拉断凸及周缘前中生界白云岩储层成因与勘探潜力

Genetic types and exploration potential of pre-Mesozoic dolomite reservoirs in Yakela fault arch and its surrounding areas, Tarim Basin

费剑炜 杨红彩 周芳芳 李晔 谷茸

Fei Jianwei Yang Hongcai Zhou Fangfang Li Ye Gu Rong

中国石化 西北油田分公司 勘探开发研究院, 乌鲁木齐 830011

SINOPEC Northwest Oilfield Company, Urumqi, Xinjiang 830011, China

钻井岩心、薄片观察和物性资料分析表明,塔北雅克拉断凸及周缘地区前中生界白云岩至少发育3种类型的白云岩储层:风化壳岩溶型、暴露浅滩型和埋藏岩溶型。风化壳岩溶型储层主要受控于古潜山形态,是本区勘探最主要的储层类型;暴露浅滩型储层主要受沉积微相控制,台内滩环境、早期大气淡水淋滤及埋藏成岩环境有机酸的溶蚀是这类储层形成的关键因素;埋藏岩溶型储层主要受埋藏期流体和成岩环境控制。本区白云岩储层形成具有多期次、多类型地质作用的特征,有利的古构造位置和原始沉积相带、建设性成岩作用(白云化作用、溶蚀作用)和断裂及裂缝的发育是白云岩储层形成的关键要素,上覆盖层特别是舒善河组的发育程度是本区白云岩储层油气成藏的关键因素。

The analyses of drilling cores, thin sections and physical properties show that there are at least three types of pre-Mesozoic dolomite reservoirs in the Yakela fault arch and its surrounding areas, including weathering crust, exposed shoal and buried karst. The weathering crust reservoirs are mainly controlled by ancient buried hills, and serve as the most important reservoir type in the study area. The exposed shoal reservoirs are controlled by sedimentary microfacies, and the environments like platform shoal, atmospheric fresh-water leaching and organic acid corrosion play important roles during reservoir formation. The buried karst reservoirs are controlled by the fluid during the burial period and the diagenetic environment. The dolomite reservoirs in the study area are formed under various geological processes during different stages. Ancient tectonic location, favorable facies, constructive diagenetic effects (dolomitization, dissolution) as well as faults and fissures are the key elements for dolomite reservoir formation. The covering formations, especially the Shushanhe Formation, are decisive for hydrocarbon accumulation in dolomite reservoirs.

中国石化西北油田分公司科研项目"雅克拉断凸中西段前中生界目标落实与评价方法技术研究"(KJ2011-07)资助.

https://doi.org/10.11781/sysydz201503286