准噶尔盆地西缘春光区块沙湾组沉积相及含油规律分析

Sedimentary facies and hydrocarbon distribution analysis of Shawan formation of Chunguang block in the western margin of Dzungaria basin

春光区块沙湾组普遍认为是辫状河三角洲沉积。通过地质综合分析与研究,指出了该区块三角洲沉积相模式所存在的矛盾,并通过对各种沉积特征和相标志的分析,提出了滩坝沉积体系模式,阐述了划相依据,指出了沉积微相带和砂体的分布规律。利用滩坝沉积模式解释了三角洲沉积模式无法解释的种种矛盾,在此基础上,分析了大型滩坝沉积体系和"板砂"的成因,提出了孤立坝体成藏和条带状分布的含油规律。

It is widely thought that Shawan formation of Chunguang block was developed in a braided river delta sedimen-tary system,however,the author in this paper believes there are conflicts in view of sedimentary facies model.Through careful studies on various sedimentary characteristics and facies marker analysis,the author insists that Shawan formation was developed in a beach bar sedimentary system and then the study on facies classification,sedimentary microfacies belts and sandbody distribution has been carried out in this paper.As a result,the conflicts unable to be explained by delta sedimentary system have been resolved.Based on that,the reasons for large beach bars and 'sand sheet' have been analyzed,and in the end the hydrocarbon accumulation and banding distribution law for isolated beach bars has also been provided.