塔里木盆地塔中北围斜中下奥陶统顶部暴露剥蚀的证据探讨

Evidence of exposure erosion of Lower-Middle Ordovician top in Beiweixie region, middle Tarim Basin

马庆佑 沙旭光 李宗杰 曹自成

Ma Qingyou Sha Xuguang Li Zongjie Cao Zicheng

中国石油化工股份有限公司 西北油田分公司 勘探开发研究院,乌鲁木齐 830011

Exploration and Production Research Institute of SINOPEC Northwest Company, Urumqi, Xinjiang 830011, China

塔里木盆地塔中北围斜地区中下奥陶统顶部是否存在暴露剥蚀，对明确该地区的储层发育主控因素及下一步勘探方向至关重要。通过对新三维地震剖面反射特征、已钻井Ro热演化剖面及裂缝充填方解石δ13C、δ18O同位素特征的分析，初步认为受加里东中期Ⅰ幕构造运动的影响，塔中北围斜地区中下奥陶统顶部遭受了不同程度的暴露剥蚀，临近塔中Ⅰ号断裂带的地区剥蚀程度增大，这将会提升该地区加里东中期Ⅰ幕风化壳岩溶领域的油气勘探潜力。

Whether there was exposure erosion of the Lower-Middle Ordovician top in Beiweixie region of the middle Tarim Basin, it is critical to identify the controlling factors for reservoir development and exploration direction in the study area. Through the analyses of the reflection characteristics of new 3d seismic profile, Ro thermal evolution profile of drilled well, and δ13C, δ18O isotopes of fracture-filling calcites, it is concluded that the Lower-Middle Ordovician top may have suffered various degrees of exposure erosion in Beiweixie region under the action of the episode Ⅰ of the mid-Caledonian. Denudation degree increases approaching to the Tazhong No. Ⅰ fault belt, which enhances the oil and gas exploration potential of weathering crust karst areas of the episodeⅠof the mid-Caledonian in the study area.

国家科技重大专项专题“塔里木盆地中央隆起区海相碳酸盐岩层系油气成藏主控因素与勘探突破目标评价”（2011ZX05005-004）资助。

https://doi.org/10.11781/sysydz201305500