鄂尔多斯盆地西南缘延长组三角洲前缘粒度概率累积曲线特征

The Characteristics of Probability Cumulative Grain Size Curves of Delta Front of Yangchang Formation in Southwest Ordos Basin

通过岩心观察和大量的粒度分析资料,对镇泾油田延长组三角洲前缘不同沉积微相粒度概率累积曲线特征进行了研究,结果表明:水下分流河道砂岩的概率累积曲线为"高斜两跳一悬式"和"两段式"两种组合特征;水下天然堤砂岩概率累积曲线为"高斜两段式"组合特征;水下决口扇概率累计曲线为"低斜两段式"组合特征;河口坝粒度概率累积曲线为"高斜一跳一悬加过渡式"和"低斜三段式"组合特征。

Base on observation of cores and plenty of analyzing data of grain size, the probability cumulative grain size curves in the ,different Sedimentary Micro--facies of delta front sedimentary environments of the Yangchang Formation in the Zhenjing Oilfield were summarized. The researches show that the distributary channels in delta front subfacies of＂high slope two--bouncing population--one suspension population＂pattern and ＂bi--segment＂ pattern; subsea natural barrier of＂high slope bi--segment＂ pattern; subaqueous crevasse splay of ＂low slope bi--segment＂ pattern ;The river mouth bars in the delta front have two patterns ,＂one bouncing population--one suspension population--transitional zone＂pattern and ＂low slope tri--segment＂ pattern.