松辽盆地北部徐家围子地区登娄库组下部沉积相分析

松辽盆地北部徐家围子地区登娄库组下部沉积时期,盆地处于断陷向坳陷转化的过渡期。本文综合分析岩芯、粒度分析和测井特征等,探讨了徐家围子地区登娄库组下部沉积相类型和储层砂体的分布规律。结果表明,本区目的层段主要发育辫状河相、辫状三角洲相和湖相3种沉积相、6种沉积亚相,以及13种沉积微相;在平面上,以湖泊为中心,辫状河、辫状三角洲环绕四周的格局。辫状河道及辫状三角洲的厚层砂砾岩为有利储集体,湖相暗色泥岩可作为源岩和盖层,二者可以构成较好的油气生储盖组合。

Sedimentary facies analysis of the lower part of Denglouku Formation in northern Xujiaweizi area, Songliao Basin

During the time when the lower part of Denglouku Formation was deposited in northern Xujaweizi area,Songliao Basin was in the transition from depression basin to faulted basin.Based on the comprehensive analyzing of the core and the logging,this paper discusses the types of sedimentary facies of the lower part of Denglouku Formation in the present area.The results show that the lower part of Denglouku Formation is mainly composed of three sedimentary facies including fluvia-,braided delta-and lake facies.They can be divided into 6 sedimentary subfacies and 13 microfacies.The reconstructed palaeogeographic map shows that lake facies in the center,surrounded by fluvial rivers and braided delta facies.The thick sandstone and conglomerate of braided delta and fluvial facies are favorite reservoirs,and dark mudstone of lake facies serves as hydrocarbon source rock and cover rock,making better combination of reservoir and seal.