Petroleum Geological Characteristics Of Jiulong Mountain Area Of Qaidam Basin

The Jiulong mountain area is located in the southwest of Shaishiteng mountainand the north of Lvliang mountain, the west segment of the northern fringe of Qaidambasin. The Jiulong mountain area which is about500Square Kilometers sourround byolder mountains in three direction:southeast、northeast、northwest, and its adjacentMahai area in southwest. There are many ground structures such as Yuka、 NorthernYuka、Western Yuka、Jiulong mountain etc. It is expected that The Jiulong mountainarea may be another oil bearing in the future, with good show of oil and gas.In order to understand deeply of reservoir-forming rule and thereservoir-controlling factors, Based on researches by means of core observation and incombination with analysis of the drilling, well logging, seismic and geochemicaldata,the principles of sedimentology、mineralogy、geochemistry and geophysical wereused to research the sedimentary system、 reservoir sand、 reservoir type andreservoir-forming rule in the study area and influencing factors is organicallyintegrated. The reservoir characteristics and controlled factors of study area areresearched. It is showed that: the reservoir rock types are mainly as clastic feldsparsand and feldspathic clast sand; primary intergranular pores and intergranulardissolution pore are the main porosity type, which belongs to low porosity andpermeability reservoir; sedimentary microfacies,lithogenesis are main factors affectingreservoir properties in this area; Study on the fluid inclusions and Application of FTIRMicro-spectroscopy indicates that: there is one hydrocarbon migration in Mesozoicand just one-period accumulation with time as late Pliocene.In study onsource-reservoir-cap assemblage、 Experiments of Hydrocarbon Generation andExpulsion、Formation time of traps for reservoir types in the area. It indicates that thehydrocarbon reservoir types in the area are mainly controlled by the dual factors ofstructure and lithology, the oil reservoir type is structural-lithological reservoirs.Self-generation and self-bearing and lower intervals generation and upper intervalreserving are the main source-reservoir-cap and Rupture System are the maincontrolling factors of oil and gas distribution.