Abstract:

There have been three tectonic evolution stages of the tectonic movements since Late Sinian in the lower Yangtze region, with the generation of thrust structural framework within the Paleozoic and Mesozoic marine formations, and thus the generation of the differentiated geological structure and thrust nappes. Moreover, the complex of former compressional basins and later faulted basins significantly controlled the hydrocarbon origin, reservoir characteristics and sealing conditions, to a great degree, bring about the reconstruction of source-reservoir-cap rock assemblages.During the processes of compressional uplift and thrust nappe forming and fracturing in the geological history, the original petroleum reservoirs had been destroyed, as well as the sealing conditions of the late accumulation reconstruction,but the hydrocarbon generation of the marine source rocks had been canceled, in favor of valid reservoir space.Extensive subsidence and superposed sedimentation increased the source rock maturity, hence the secondary hydrocarbon generation.Meanwhile, the seal ability in the region was decreased through the highly developed diagenesis and brittleness of the seal.

Key words: lower Yangtze region, tectonic movement, petroleum accumulations condition, source-reservoir-cap rock assemblages, reconstruction