辽河凹陷东部桃园—大平房地区东营组层序地层及沉积特征

采用测井和地震资料及米兰科维奇旋回相结合的方法,对辽河盆地东部凹陷桃园—大平房地区东营组层序地层进行研究,把该区东营组划分为3个三级层序(Sq1、Sq2、Sq3)。通过对自然伽马测井曲线进行频谱分析,发现地层中保存着厚度稳定的地层旋回,地层旋回厚度的变化范围为15.625~25.510 m,且其主要受米兰科维奇旋回的偏心率控制。据此,采用F ischer图解法,求取其可容空间变化速率曲线,指导层序的正确划分。根据单井相、地震相和砂体形态等综合研究的结果,确定Sq1为扇三角洲沉积,Sq2和Sq3为河流相沉积,为有利储层分布预测打下基础。

Study on the Sequence Stratigraphy and Sedimentary Characteristics of Dongying Formation in Taoyuan-Dapingfang Area in the East of Liaohe Depression

The sequence stratigraphy of Dongying Formation in Taoyuan-Dapingfang area in the east of Liaohe depression,has been studied through the combination of the logging and seismic data,and Milankovitch cycle,and can be divided into three tertiary sequences as follows Sq1,Sq2 and Sq3.By means of analyses of the spectra of well logs,i.e.GR,it can be deduced that the strata keep steady strata cycles,which are controlled by the eccentricity of the Milankovitch cycle,and the changing thicknesses of the stratigraphic cycles are 15.625 to 25.510 meters.Hereby,the Fischer diagramming method is adopted to get the speed curve of changing accommodation,and then to instruct the accurate division of the sequence.According to the comprehensive study of the single-well facies,seismic facies and the modality of sandstone body,it is indicated that the tertiary sequence Sq1 is a fan delta,and the other two Sq2 and Sq3 are fluvial facies,on which the prediction of the distribution of the profitable reservoir is based.