Study On Hydrocarbon Accumulation Rule For Jurassic And Cretaceous In Center 3rd Area Of Junggar Basin

With the information from the other people, there exist a lot of considerable hydrocarbon resources in the Jurassic and Cretaceous of center 3rd area of Junggar Basin which in the Junggar Basin's hinterland. So, it's important to research the Jurassic and Cretaceous' hydrocarbon generation rules in this area. In order to establish the hydrocarbon accumulation model of Jurassic and Cretaceous, and sum up the hydrocarbon generation rules and then forecast and estimate the advantage area about hydrocarbon enrichment, this article will in depth study the petrological characteristics, division of sequence stratigraphy, characteristics of depositional facies, characteristics of the reservoir and the hydrocarbon accumulation's main control factors.The middle and fine sandstone is the primary type of the Jurassic and Cretaceous of center 3th area, and it also has some lithic arkose and a little lithic sandstone. Braided channel, under water branch channel and alluvial fan is the main sedimentary microfacies, and the sand body has developed in the Jurassic Xishanyao Formation and the lower segment of the Cretaceous Qingshuihe Formation. The reservoir is low-porosity and extremely low-porosity, extremely low-permeability and ultra low-permeability, and also have low- permeability reservoir. The reservoir space mostly is the primary intergranular pore, and the low resistivity reservoirs also exist in the area. The reservoir capabilities of the braided channel and the under water branch channel is better than the alluvial fan.Based on the research, the material foundation of the hydrocarbon accumulation is the development of the Changji sag's multiple hydrocarbon source beds; the overlying lithologic and pressure's plugging is provide the being of eservoir a good guarantee; the development of the High-quality sand body in the favorable sedimentary microfacies, can provide reservoir space for the hydrocarbon accumulation; the development and evolution of Che-Mo uplift is form many lithologic trap, stratigraphic trap and lithologic- stratigraphic complex trap, them can provide storage space for the hydrocarbon accumulation; the fracture which is formed in earlier have connected the source rock and the reservoir sand,the later intraformational fracture and the compages of unconformity surfaces can be the"solid and braiding transforming"channel, all of this,make the hydrocarbon accumulation of hereabout the unconformity surface come true. There are three times of hydrocarbon filling in this area and the hydrocarbon is primary produced from the sand body of the unconformity surface's neighborhood. The pressure is as high as the petroleum production, because the pressure-out which from the hydrocarbon filling. In short, we can generalize the characteristic of the hydrocarbon accumulation that is "multi-period hydrocarbon generation, mixed sources infill injection, fracture and unconformity produce high efficiency transport, final reservoir generation after the late reformation". At last, there could allocation two exploratory wells, which called Jianl well and Jian2 well. In hopes to hydrocarbon exploration success in the Jurassic Xishanyao Formation, the Jianl well should be in the northeast upper slope of Yongl well, and the structural situation is relatively high; then the Jian2 well's main task in to exploration the 1 st sand group in the lower segment of the Cretaceous Qingshuihe Formation and to exploration the 1st and 2ed sand group in the Jurassic Xishanyao Formation, which could obtain breakthrough of hydrocarbon exploration.