The Yinger Depression Lower Cretaceous Reservoir Geochemical Studies

This thesis takes the petroleum system theory and the oil reservoir geochemistry theory as the guide, inducts oil and gas "partition capture" and the biomarkers quantitation research thought, applies the entire hydrocarbon geochemistry method for the oil and gas reservoir geochemistry in Ying'er depression basin, establishes its petroleum migration and accumulation model, discovers the law which controls the pool, appreciates the exploration foreground of west slope in Ying'er depression basin, points out the favorable exploration area.Through the hydrocarbon source rock appraisal, the geochemistry methods: the natural gas composition and the isotope analysis, the light hydrocarbon, biomarkers contrast analysis research, and so on, had determined the oil/gas type and its distribution rule in Ying'er depression basin. There is three hydrocarbon source rocks including zhonggou group, xiagou group and chijinbao group in research area, among which the zhonggou group and chijinbao group are effective petroleum source bed. Xiagou group lies in the phrase with mature petroleum source and chijinbao group lies in the phrase with high mature petroleum source. The crude oil including viscous crude with low maturity, crude oil with average maturity and condensate with high maturity comes from xiagou and chijinbao group in beneath chalk. There exist three abnormal liquid pressure belts with same depth and different period. The crude oil assembles in the normal pressure belt between two high pressure belts or in the top of abnormal high pressure belt.The principle of oil conglomeration in Ying'er depression basin is characterized by "fault-control, source-control and formation-control". That is to say, the oil distributing in Ying'er depression basin is obviously controlled by faults. The planar distributing is determined by the domination of heiliang fault. The short-distance migration of oil make chijinbao ancient structure that is adjacent to the petroleum source depression a main place of oil conglomeration. In portrait, the chijinbao group in beneath chalk has a good condition to be a petroleum deposit, which is a main target formation in the hydrocarbon prospecting in Ying'er depression. In one word, in ying'er depression, the east area of heiliang fault was an advantaged prospect area, in which the source rock in xiagou and chijinbao group was essential. Its direction should approach the north direction and the depression.