河流相单河道砂体刻画——以准噶尔盆地西北缘一中区及三4区三叠系克下组为例

Single Sand Body Description of River Facies: Lower Karamay Formation of Triassic in Area 1Z & Area 34, Northwest Junggar Basin as Examples

以克拉玛依油田一中区和三4区为例,以建立整个一三区的地层对比格架为基础,结合前人研究成果、野外露头资料和测井解释,将一中区及三4区辫状河和曲流河分别划分为3种亚相4种微相。对各个单砂层时期沉积的单河道砂体进行识别,总结了识别单河道砂体的5种常用方法。综合运用这5种方法,将一中区和三4区单河道砂体归为3类7种(完全切叠式、不完全切叠式、交错式、单边对接式、多边对接式、似对接式,孤立式),对不同类型单河道砂体的宽度、厚度、宽厚比进行了统计,表明河流相单砂体宽度和厚度成正相关关系;通过两个区块克下组不同单河道沉积时期的单河道砂体平面分布图,认为河流相辫状河单河道常由连片状砂体和交织带状砂体组成,曲流河单河道通常由带状砂体和交织带状砂体组成。

With Area 1Z and Area 34 in Karamay Oilfield as examples, the stratigraphic division and correlation framework of Districts One and Three is built. Based on the previous results, the outcrop data and the logging interpretations, and the environment of river sediments, the braided river and the meandering river are divided into 3 subfacies and 4 microfacies. Five identification methods of single sand bodies and their applications are analyzed. Using these 5 methods, the single sand bodies of Area 1Z and Area 34 are divided into 3 categories （7 types in all）. Also, statistical analyses are made on the width, the thickness, and their ratio for each type. It is shown that the width and the thickness of river single sand bodies are positively related. Finally, the distributing maps of single sand bodies of each period are obtained, with single channels of braided rivers mostly consisting of sheet-like and interweave banded single sand bodies, and single channels of meandering rivers mostly consisting of banded and interweave bandedsingle sand bodies.