Advance of comprehensive hydrocarbon geological survey and research of Sinian-Lower Paleozoic within the mountain-Basin transition zone of west side of Xuefeng Mountains, in Middle-Upper Yangtze region of Southern China

The basin-mountain transition zone of western Xuefeng Mountain，located between Sichuan Basin and Xuefeng Mountain, is a new oil and gas exploration area of Sinian-Lower Paleozoic. This paper focuses on the major progress made by a large number comprehensive hydrocarbon geological survey in recent years: First, the establishment of a more perfect multiple stratigraphic division and correlation program and typical microfossils and isotope profiles of Sinian-Lower Paleozoic, by comprehensive utilization of the latest comprehensive geological survey, microfossils and isotopic formation analysis. Second, to identify basic characteristics of the major folds, fractures, slip layers and tectonic framework of this region，and further confirm that Xuefeng Mountain is a quasi-situ uplift. Third, to restore higher accurate lithofacies palaeogeography and sedimentary filling evolutionary sequences during Sinian-early Paleozoic, and designate multiple reef facies belts. Fourth, more detailed delineation of favorable source rocks and reservoirs zone of Sinian-Lower Paleozoic nine key layer group. Fifth, by anatomical think that tectonic uplift and faulting of the region and adjacent areas of ancient reservoirs are main controlling factors formed by ancient reservoirs, especially fracture is the most critical factor in the decision of nowadays oil and gas preservation and exploration. Sixth, Sinian-Lower Paleozoic in the area divided into three sets of favorable combination of reservoir, preferably four favorable hydrocarbon prospective areas. The work has laid an important basis to promote to carry out oil and gas exploration target area preferred and new discoveries of oil and gas exploration in the area.