川西坳陷中段沙溪庙组测井相和地震相及砂体展布特征

通过测井相、地震相和沉积相关系的综合分析 ,建立了沙溪庙组测井相 -地震相 -沉积相转换关系 ,揭示了川西坳陷中段沙溪庙组纵向上沉积演化具有从下沙溪庙组下部的浅湖相沉积向上部的半深湖相沉积过渡 (以叶肢介页岩为代表 ) ,之后湖水位持续下降 ,复变浅为上沙溪庙组底部的浅湖和中下部的三角洲前缘沉积 ;中部演变为强烈进积的三角洲平原相沉积 ;而上部为曲流河沉积 ,从而构成完整的湖进 -湖退沉积演化序列 ,为砂体展布规律的预测提供了依据

LOGGING FACIES, SEISMIC FACIES AND SAND BODY DISTRIBUTION OF SHAXIMAO FORMATION IN THE MIDDLE WESTERN SICHUAN SAG

Through a synthetical analysis for the connexion of logging facies, seismic facies and sedimentary facies , the authers set up the relationship between the logging facies, seismic facies and sedimentary facies and reveal the sedimentary development law of the Shaximiao Formation, Middle Jurassic in the middle Western Sichuan Sag. That is, the evolution of sedimentary facies is a deepening process from a shallow lake to a seimi deep lake in Lower Shaximiao Formation, then, in the Upper Shaximiao Formation, the lake water becomes shallow and the sedimentary facies types change relatively, from the bottom to the low middle section and middle section till the top section, the sedimentary facies develop from a shallow lake to a delta front, intensely prograding delta plain and the meandering river. Therefore, these changes compose a complete prograding retrograding sedimentary sequence from a lake to a river. These provide the basis for pridicting the distribution law of sand bodies of the formation in the Middle Western Sichuan Sag.