塔里木盆地震旦系-寒武系不整合面特征及油气勘探意义

塔里木盆地震旦系—寒武系不整合面在盆地内部及周边露头区广泛发育。通过地震资料追踪及露头地质剖面研究,认为震旦系—寒武系不整合面主要有两种类型:平行不整合和角度不整合。平行不整合主要分布在库鲁克塔格、柯坪露头区及盆地北部坳陷及其以北的广大地区;角度不整合分布在中央隆起带(英东构造带—塔东低凸起—塔中低凸起—巴楚断隆)的北翼附近,自东向西地震剖面结构表现清晰。震旦系白云岩受该期不整合面影响,遭受大气淡水溶蚀作用,形成古岩溶型储层,中央隆起带北翼角度不整合分布区为震旦系白云岩古岩溶型储层的有利勘探部位。

Characteristics and petroleum exploration significance of unconformity between Sinian and Cambrian in Tarim Basin

The unconformity between Sinian and Cambrian strata is widespread developed within and around Tarim Basin. Two types of unconformities are presented in the study area based on the seismic and geological outcrop analysis. One type is parallel unconformity which locates in Kuruktag,Kalpin and the northern depression and its north area. The other type is angular unconformity which developes near the north ramp of the Central Rise(Tadong low uplift Tazhong low uplift Bachu fault uplift)and can be clearly identified from the east west trending seismic records. Palaeokarst dolomite reservoirs of Sinian were formed associated with the unconformity between Sinian and Cambrian. Beneficial direction of the Palaeokarst dolomite reservoirs of Sinian in Tarim Basin is north ramp of the central rise where the angular unconformity distributes.