塔里木北部新元古代裂谷盆地古地理格局与油气勘探潜力

The paleogeographic framework and hydrocarbon exploration potential of Neoproterozoic rift basin in northern Tarim Basin

基于露头、钻井、地震等资料,在明确地层充填序列及建立地层格架基础上,分析塔里木北部新元古代裂谷盆地古地理演化格局及其油气勘探潜力。在Rodinia超大陆聚合与裂解的背景下,塔里木新元古代发育塔北古陆和塔里木古陆,两者中间夹持EW走向的弧后裂谷盆地,东北部库鲁克塔格地区和西北部阿克苏地区充填巨厚的海相碎屑岩、碳酸盐岩和火山岩,包括冰碛岩,发育深海、浅海、滨海环境和三角洲、冰海过渡性环境。早南华世—晚震旦世,北部裂谷盆地总体由深海演化至滨浅海环境,岩性由碎屑岩向碳酸盐岩转变。根据野外烃源岩和生产数据认为,塔里木北部具有烃源岩和储层形成的良好条件,新元古界具有一定勘探潜力。

Based on the outcrop, drilling, and seismic data as well as the clarified stratigraphic filling sequence and framework, a sys tematic analysis is made on the paleogeographic evolution pattern and hydrocarbon exploration potential of Neoproterozoic rift basin, north Tarim. Since the aggregation and breakup of Rodinia supercontinent, Tabei paleocontinent and Tarim paleocontinent were de veloped in Neoproterozoic Tarim, with an EW-trending back-arc rift basin between them. The northeast Kuruktag area and north west Aksu area are filled with hugely-thick marine clastic rocks, carbonate rocks and volcanic rocks, including tillite rocks, where abyssal sea, neritic sea and littoral sea environments are developed as well as delta and ice sea transitional environments. In Early Nanhua-Late Sinian, the north rift basin generally evolved from abyssal sea to littoral-neritic environment, where the lithology transited from elastic rocks to carbonate rocks. According to field source rocks and production data, the north Tarim has good conditions for the formation and preservation of source rocks and reservoirs, proving certain Neoproterozoic exploration potential.