堡子湾地区长6油层组储层沉积相研究

Sedimentary facies of Chang 6 oil measures in Baoziwan Area,Ordos Basin

为了对堡子湾地区长6油层组的沉积相有一个明确认识,以岩心相分析为基础,综合鄂尔多斯盆地南部长6油层组砂岩储层的储层岩性、沉积构造及粒度等方面的特征,对沉积相平面展布规律进行了分析.确定了目的层段以内陆淡水湖泊三角洲沉积体系为主,并且主要为三角洲前缘亚相;其具体微相包括水下分流河道、河口砂坝、分流间湾、远砂坝、席状砂、水下天然堤与水下决口扇6类,其中,水下分流河道、河口坝、远砂坝是勘探的有利相带。建立了三角洲亚相三维空间相模式,为储层有利储集相带预测奠定了地质基础。

This article describes the characteristics of lithology, sedimentary structure and grain grade of Chang 6 oil measures sandstone reservoirs in the south of Ordos Basin in order to get the knowledge of the oil measures in Baoziwan Area on the basis of the core facies analysis. The plane distribution rules of sedimentary facies are analyzed. It determines that the objective intervals are mainly the inland freshwater lake delta sedimentary system and that the main subfacies are the delta front subfacies. The microfacies includes the underwater distributary channel, channel mouth bar, bay beside distributary channel, distal bar, sand sheet, underwater natural levee, underwater crevasse splay, in which the underwater distributary channel, channel mouth bar and distal bar are the advantageous facies belts. The three-dimensional space facies model of delta subfacies has been found, which has laid a foundation for the anticipation of advantageous facies belts.