冀东南堡凹陷古近系东营组构造对扇三角洲的控制作用

Control of the structure of the Paleogene Dongying Formation upon fan-delta deposition in the Nanpu Depression,Jidong oilfield

刘延莉 邱春光 邓宏文 李茗

Liu Yanli Qiu Chunguang Deng Hongwen Li Ming

根据边界断裂特点和东营组地层发育特征,南堡凹陷划分为陡坡带、凹陷带和缓坡带3个构造地貌单元.钻测井和地震资料研究表明,陡坡带主要发育扇三角洲沉积体系,受制于古构造-古地貌背景的不同,储层粒度、发育规模等方面存在明显差异.可进一步划分出断-台、断-阶和断-崖3类扇三角洲成因模式,3种模式形成的扇三角洲沉积体系在油气储集能力方面的差异性较大.其中,断-台地貌形成的扇三角洲平原亚相和扇三角洲前缘亚相、断-阶地貌形成的扇三角洲前缘亚相是形成优质储层的有利相带.

Boundary fault features and deposition characteristics of the Dongying Formation support a division of the Nanpu depression into three structural units,namely the steep slope zone,the depressed zone,and the gentle slope zone.The analysis of drilling,log and seismic data points out that fan-deltaic depositional systems are mainly developed in the steep slope zone and are controlled by different paleo-structures and paleogeomorphology,thus showing clear disparity in grain size of reservoir rock and development scales.Based on these observations,the paper sums up three fan deltaic genetic models,including fault-platform,fault-terrace,and fault-scarp.They differ tremendously in reservoir capacity.The delta plain subfacies and fan delta front subfacies developed in the fault-platform setting and the fan delta front subfacies developed in fault-terrace setting are considered as the favourable facies belt for forming high quality reservoirs.

10.11743/ogg20080115