Tectonic Characteristics and Hydrocarbon Accumulation Rules of Lateral Buried Hill Transformation Belt in the Raoyang Sag

Based on well drilling and seismic data, the characteristics and mechanism of lateral buried hill transformation belt were studied. The result shows that the Raoyang buried hill transformation belt formed firstly by Mesozoic differential tectonic erosion and then by Cenozoic differential tectonic deformation; in response to different tectonic subsidence among tectonic units, a series of buried hills which took bedrock detachment surface as a carrier collapsed in order from east to west. Logging, test and laboratory analysis data confirm that buried hill transform zones are characterized by multiphase filling of and gas in time, heterologous accumulation in plane, differential hydrocarbon accumulation in profile, forming a compound and gas accumulation zone, which are dominated by buried hill hydrocarbon reservoir, with Tertiary hydrocarbon reservoir as supplement. Strong tectonic deformation of buried hill transform zones provides favorable conditions for formation of trap and reservoir. Under the guidance of oil and gas differential accumulation principle, it will be our task to analyze the spatial distribution of inner hydrocarbon reservoirs in buried hills, search for favorable exploration target, and extend prospecting area in buried hill of the Jizhong depression.