介绍了临南油田田口区块邻区沙三中亚段的沉积特征。依据岩性、生物、测井响应、岩相突变等特征和滞留沉积物标志识别出沙三中亚段的准层序和层序界面 ,并将中期旋回划分为积―弱加积型、积型、加积―弱进积型和对称型等 4型。根据上述界面和类型将沙三中亚段细分为若干体系域 ,认为含油气层系主要分布在湖侵体系域。

Depositional characters are introduced in the middle member of Shahejie Ⅲ in Tiankou and its contiguous block in Linan oil field. Parasequences and interfaces of sequence in the middle member of Shahejie Ⅲ are recognized by lithologic characters, paleobiology, response of logs, accident of lithofacies and residual sediment. And then the mid term cycle is divided into four types such as retrogradation weak aggradation, retrogradation, aggradation weak progradation and symmetry. The middle member of Shahejie.