关键词: 德令哈坳陷, 中侏罗统烃源岩, 生储盖组合, 勘探新领域

Abstract: According to the study on field geological survey, comprehensiv e seismic data interpretation, and general evaluation of exploration ta rgets, Delingha depression, along the ea stern segment of the block-faulted zone in the northern ma rgin of Qaidam Basin, is considered as a n extensional depression developed in the Middle a nd Late Jurassic-Early Cretaceous of Mesozoic. After undergoing the stages of transtension sag in Tertiary and compressive sag in Quaternary, the hydrocarbon source rocks from Member four to sev en of the Dameigou Formation in Middle Jurassic were stably distributed in Delingha depression and potentialhydrocarbon generation rocks of Carboniferous were developed in the depression as well. Reservoirs are distributed in all layers, in which the quartz sandstone of Member six in Dameigou Formation and the fluvial deltaic sandstones of Cretaceous are the most common reservoirs of Mesozoic.Traps a re ma inly distributed in sa lient belts, and nappe structural belts are developed in the front of mountain area. It is considered tha t the forming time of structures matches the time of oil and gas reservoir formation, making it possible to form reservoir-seal a ssemblage featured as self-generation and self-storage and lower-generation and upper storage. According to the assessment on the exploration potentia l and prospects of the oil and gas resources in Delingha depression, it is believed that the self-genera tion and self-storage oil-gas reservoir forming assemblage in the Middle Jurassic is the most rea listic exploration a rea. What's more, Tuonan stage benches, the thrusting belt of Zongwulong, and the Aimunike uplift zone are considered to be the major sa gs for hydrocarbon generation, which have certain exploration prospects.