| Laoting Depression is located in the northeast of Huanghua Depression, and it is a reconstructed Mesozoic and Cenozoic half graben basin that controlled by NEE Luanhe fault. Due to the strong tectonic movement, hydrocarbon accumulation process is extremely complex. Therefore, based on the analysis of tectonic evolution, the thesis mainly focus on analyzing hydrocarbon accumulation conditions, processes and disciplinarian to evaluate the exploratory prospect.Laoting Depression is an extensional fault basin with NW, NE and EW fault system developed. It mainly went through extensional rift period in Mesozoic, extensional chasmic stage in Paleogene and extensional depression in Neogene, and mainly develop fan delta in Mesozoic and fluvial-lacustrine facies in Cenozoic.The source rocks of Laoting Depression are dark mudstone in Paleogene and upper Cretaceous. The upper Cretaceous source rock with KerogenⅡ2 is low mature to mature. The Paleogene source rock with KerogenⅢis immature to low mature. The upper Cretaceous source rock is effective hydrocarbon source rocks.The Mesozoic clastic rock reservoir has medium porosity and low permeability with corrosion pore, corrosion gap and fracture. The upper layer on Mesozoic include Paleogene lacustrine mudstone which is rich both in range and thickness so that has ability to cover oil and gas.The combination of source rock, reservoir and cap rock in Laoting Depression have 3 series in Mesozoic. Hydrocarbon is generated and migrated in the end of Ed, when the Mesozoic traps have been formed already. At the same time the Luanhe Fault and its main branches in long extension and far heaves form good space relationship with main sand body and the unconformity.Based on comprehensive analysis and analog hydrocarbon accumulation characteristics in adjacent areas, the most preferred plays are in the center low uplift, east sub-depression and slop in the east sub-depression, and design three exploration wells. |
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