Mechanism of Overpressure Formation in the Youquanzi Oilfield in western Qaidam Basin
Overpressure is widely developed in the Cenozoic formation of the Youquanzi Oilfield in western Qaidam Basin,and the identification of overpressure genesis has great significance for the study of oil-gas migration and reservoir formation.The measured pressures,logging curves,acoustic velocity-density cross plot,overpressure genesis comprehensive analysis method and overpressure compartment mode for the Youquanzi Oilfield were compre-hensively analyzed.The results show that the negative pressure,normal pressure,overpressure and strong overpres-sure systems were longitudinally developed in the Cenozoic Formation of the Youquanzi Oilfield;the pressure coeffi-cient of the overpressure system was generally greater than 1.3,and the pressure coefficient of some overpressure points was greater than 1.73,showing the characteristics of strong overpressure;overpressure in this area,the main controlling factors were the uneven compaction,tectonic extrusion and hydrocarbon generation;the oil-gas migra-tion was in line with the overpressure compartment mode;the oil and gas were migrated to the Nanyi Mountain Area due to overpressure.The study result clarifies the oil-gas migration direction of the Yauquanzi Oilfield and is of guiding significance to the study of oil and gas reservoirs in western Qaidam Basin and similar regions.
万方数据
维普
