准噶尔盆地玛湖凹陷斜坡区三叠系百口泉组地震层序格架控制下的扇三角洲亚相边界刻画

The Subfacies Boundary Description of Fan Delta under the Control of Sequence Stratigraphy of Triassic Baikouquan Formation in the Mahu Slope Area,Junggar Basin

准噶尔盆地玛湖凹陷斜坡区三叠系百口泉组由于各区带钻井地层划分方案不统一且缺少等时概念,制约了对斜坡区有利相带展布的整体认识。通过井—震结合搭建全区层序地层格架,整体识别了百口泉组内部3个四级层序界面。在此基础上按照"点—线—面"的识别思路,利用岩心和测井资料实现点、线层序地层划分和沉积体系组成特征的认识,利用地震沉积技术实现由线至面分析层序演化规律及沉积亚相边界刻画。研究明确了玛湖凹陷斜坡区有利前缘相带面积约为13 000km2,且在凹陷中心区也大面积发育前缘相带,拓宽了斜坡区勘探面积和场面。

The overall understanding of favorable facies was limited of Triassic Baikouquan Formation in the Mahu slope area of Junggar Basin because of the inconsistent drilling stratigraphic division and non-Isochronism.Through the combination of well and seismic,sequence stratigraphic framework was built,and a four-level sequence interface was recognized for the Baikouquan Formation.According to the idea of'point-line-surface',using the core and logging data,the sequence stratigraphy can be divided and the sedimentary system characteristics can be recognized.Using the seismic deposition technology,the sequence evolution and the subfacies boundary can be described.The favorable fan delta front facies area of the Mahu slope is about 13 000km2,and the central sag also developed a large area of front facies.The research broadened the favorable area.