准噶尔盆地车排子凸起沙湾组成藏主控因素

准噶尔盆地西缘车排子凸起是有利的复式油气聚集区, 近年来在其新近系沙湾组沙二段发现了一批高产岩性油藏, 实现了浅层勘探的重大突破。在研究剖析沙二段油气分布与典型油藏特征的基础上, 重点对沙二段油气主控因素与成藏模式进行了探讨及总结, 提出“湖扩滩坝砂、油气输导体系、侧向封堵条件、古构造脊”是控制油气成藏的4大要 素和“远源、晚期聚集、多因素控藏”的油气成藏模式。指出, 与古湖岸线平行分布的滩坝砂体是今后钻探的重点目标。

Main Factors Controlling Hydrocarbon Accumulation in Neogene Shawan Formation in Chepaizi Swell of Junggar Basin

Chepaizi swell in western margin of Junggar basin is a favorable area with composite hydrocarbon accumulation. In recent years, a number of prolific lithologic reservoirs have been discovered in the Sha-II member of Neogene Shawan formation, representing an important breakthrough in shallow-depth exploration. This paper analyzes the hydrocarbon distribution and typical reservoir characteristics of the Sha-II member, discusses its main factors controlling hydrocarbon accumulation and reservoir pattern, and proposes four main elements to control hydrocarbon accumulation such as lake-enlarged beach bar sands, hydrocarbon conduit system, lateral barrier conditions and paleostructural crest, and the reservoir pattern controlled by multi-factors of distal source and late accumulation. The beach bar sands parallel to the paleo-lake strandline could be the key target for further exploration.