关键词: 层序地层, 米兰科维奇旋回, Fischer图解, 东营组, 辽河盆地

Abstract:

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.

Key words: sequence stratigraphy, Milankovitch cycle, Fischer diagram, Dongying Formation, Liaohe basin