Junggar Basin Luliang Reservoir Geochemical Studies

This thesis takes the petroleum system theory and the oil reservoir geochemistry as the guide, inducts the"oil-gas partition capture"and"oil-gas reservoir redistribution" research clue, applies entire hydrocarbon geochemical method inncluding gas composition and carbon isotope, light hydrocarbon, biological marker and different numerator segment to study the oil-gas source correlation and reservoir geochemistry of Luliang oil fleld.The thesis summarizes the petroleum migration and accumulation regularity and establishes its mode, at the same time appraises the exploration foreground and points out the favorable exploration area.The paper has summarized the oil-gas distribution regularities of Luliang oil field, clearly ascertained oil-gas maturity and type, studied the oil-gas sources and its genesis. The thesis also analyzes the relationship between the crude oil biodegradation and the forming reservoir, points out that the degradation had happened in situ, with the reservoir inclusive makes certain of the oil-gas to reservoirs' issue and time. With the migration study and the structural evolution history, the oil/gas migration and accumulation model was established. At least two periods petroleum accumulation existed in Luliang oil and gas field. The first issue oil was the Fengchen group mature hydrocarbon, at latter stage of Early Cretaceous and early stage of Upper Cretaceous, which had mostly entered into Jurassic and deep Cretaceous reservoir and suffered from the serious biodegradation, but the crude oil in Jurassic (J_2x4) reservoir was perfectly preserved. The second issue was Wuerhe group mature hydrocarbon, at Palaeogene period ,little of them had supplemented the Jurassic first stage oil-gas reservoirs but more of them following the dislocation keeped on upwards moving and mixed with the strong biodegradable crude oil. Subsequently the shallow Cretaceous oil reservoirs had suffered from not too serious biodegradation, thereby the law of nowaday hydrocarbon occurrence appear.Through the analyse, faultage and unconformity were the main migratory thoroughfare. Nowaday the oil-gas reservoir is the secondary oil-gas reservoir, which was the redistribution of the old reservoir. The deep-seated old reservoir is the main object that we prospect for in this area of the future.