准噶尔盆地西北缘红山油田侏罗系齐古组沉积相研究

Sedimentary Facies of Jurassic Qigu Formation in Hongshan Oilfield in the Northwestern Margin of Junggar Basin

通过岩心观察、沉积构造、沉积序列、分析化验、录井、测井以及区域构造背景等资料对红山油田侏罗系齐古组(J3q)沉积相进行研究。研究表明,J3q为一套辫状河三角洲沉积体系,由下向上发育有辫状河三角洲平原、辫状河三角洲前缘、前辫状河三角洲3类亚相以及河床、河漫、水下分流河道、支流间湾等7类微相;总体上看其具有明显的退积式层序,在齐古组一段(J3q1)有小范围的次一级进积式层序;辫状河三角洲前缘的水下分流河道为优势油气储集层,其次为辫状河三角洲平原的河床微相。

By using the data of core observation,sedimentary structures,sedimentary sequence,laboratory analysis,geologic logs,well logging and regional structural background,the sedimentary tectonics in the area were analyzed.Studies show that the Jurssic Qigu Formation of Hongshan Oilfield is a set of braided river delta sedimentary system,from bottom up there develops 7types of microfacies,such as braided river delta plain,and braided river delta front sub-facies and braided river delta plain sub-facies as well as riverbed,alluvial flat,underwater distributary channel,tributary bay.Generally it has obviously a retrograding sequence,while in the 1st member of Qigu Formation,there exists a small range of second-level regressive sequence.The underwater distributary channel in the Braided river delta front is the dominant oil and gas reservoir,the next is braided river delta plain facies.