四川盆地上石炭统黄龙组沉积相分析

Analysis of Sedimentary Facies of Upper Carboniferous Huanglong Formation in Sichuan Basin

根据四川盆地上石炭统黄龙组野外剖面和钻井岩心观察以及镜下岩石薄片鉴定分析,并结合岩性、古生物及测井等沉积相标志研究以及区域沉积背景和岩性组合特征,认为四川盆地黄龙组主要发育一套潮坪—陆棚沉积体系,其中潮坪体系主要发育碳酸盐岩潮坪相,陆棚体系以周缘受局限的海湾陆棚相为主。并进一步划分出4个亚相带和10个微相带。编制了黄龙组一段、二段和三段的沉积微相平面图,指出潮间坪浅滩、潮间藻砂坪、潮下坪浅滩、滨外浅滩微相为本研究区储层性能最有利的沉积相带。

It is shown that tidal flat facies and shelf thcies sedimentary systems develop in Upper Carboniferous Huanglong Formation in Sichuan Basin. The tidal flat system commonly consists of carbonate tidal flat facies and the shelf facies mainly of periphery-limited gulf shelf facies. On the basis of analyzing sedimentary facies marks and single wells, the researched Huanglong strata are divided into four subfacies and ten microfacie and the Huanglong Member-1, Member-2 and Member-3 maps of sedimentary micro-facies plane-distribution are compiled. It is indicated that the most favorable microfacies for prospective are intertide fiat shallow shoal, intertidal algae sand flat, subtidal flat shoal and offshore shallow shoal sediments.