UPPER PALEOZOIC SEQUENCE STRATIGRAPHIC FRAMEWORK AND SOURCE-RESERVOIR-CAP CHARACTERISTICS IN EASTERN LIAONING PROVINCE

The Upper Paleozoic Carboniferous-Permian strata are well developed in eastern Liaoning Province. Based on the regional tectonic sedimentary evolution, rock association characteristics and sedimentary facies analysis, the paper studies the sequence stratigraphy of Upper Paleozoic in eastern Liaoning with the theory and method of sequence stratigraphy. The Carboniferous Benxi Formation-Permian Hamashan Formation is recognized as 1 supersequence including 6 sequences, which are developed in epicontinental sea, shoreland, delta and fluvial sedimentary setting respectively. By establishing the regional sequence stratigraphic framework, the paper discusses the development characteristics of source-reservoir-cap assemblages with system tract as unit in the sequence stratigraphic framework. It is considered that the Upper Paleozoic regional source rocks and caps were mainly formed in the condensed section and upper transgressive system tract, and the lower highstand system tract, with the favorable reservoirs mainly developed in the lowstand and transgressive system tracts, forming two types, five sets of source-reservoir-cap combinations vertically, among which the self-generation and self-reservoir type of Shanxi Formation is the most favorable assemblage of Upper Paleozoic tight sandstone gas.