The Main Controlling Factors Research Of Oil & Gas Forming In Upper Paleozoic In Jiyang Depression In Bohaiwan Basin

The Jiyang depression has been a large productive base of petroleum after many years prospecting. Now the petroleum resource are found mostly in Shahejie formation and above the strata, but the deep strata are not prospected enough especially the coal of upper Paleozoic . For finding out the main control factors of upper paleozoic source rock in Jiyang depression, under the oil geology and other science's guidance, this report mainly research the upper Paleozoic oil geology and the petroleum accumulative conditions. At last this report point out the favorable prospected play .Jiyang depression is a typical multicycle superposition basin which underwent complicated tectonic movement after the Indosinian period. The multicycle tectonic movement make the upper Paleozoic source rock having secondary hydrocarbon-generation characteristics, and the period of macroscale secondary hydrocarbon-generation is late early Teriary. Based on the different tectonic-buried history, the compages types are compartmentalized four types which are that rock uplift from Mesozoic to Cenozoic, sag in Mesozoic and uplift in Cenozoic, uplift in Mesozoic and sag in Cenozoic and sag from Mesozoic to Cenozoic. The secondary hydrocarbon-generation ability of the four types are ordinal degraded. The upper Paleozoic reservoir is sands of Shihezi formation and Shanxi formation , and the effective reservoir mostly distribute above the buried hill and around the fault. The upper Paleozoic cover is mudstone of upper Shihezi formation and Shiqianfeng formation.We research the reservoir which the petroleum source come from upper Paleozoic and compartmentalize the assemble types into three. Based on the dissection of representative wells , we know the different assemblages have different controlling factors. Taking the upper Paleozoic self generation-reservoir assemblage as emphases, the main controlling factors are whether the secondary hydrocarbon-generation, covers ,reservoir and the trap are good enough. Thinking the condition of the above , we point out that Linpanjia,Gudao-Gubei,Zizhen and south Dongying are the best exploratory area and Xinyang and Chezhen are the better exploratory area.