On the basis of daily observation data and products of numerical forecast,two cold wave weather cases occurred in winter of 2008-2009 in Ningxia region were discussed by using synoptic analysis method and combining cold wave forecast index in winter of Ningxia,including the circulation background,the influence system,synoptic formation cause,ect.

According to the component and carbon isotopic compositions of gases from three main reservoirs including the Lower Triassic Jialingjiang Formation,the Middle Carboniferous Huanglong Formation and the Lower Permian,the origin of natural gas and the main source rocks were determined in combination with the distribution of source rocks.

By using the whole hydrocarbon geochemistry method, combined with the three row structures characteristics in the south margin of Junggar basin, based on the oil-gas sources and the natural gas genesis, the formation history of oil-gas pools in Hutubi, Tugulu and Qigu has been analysed deeply.

Source characteristics and gas origin of Xujiahe Formation, Upper Triassic in Chishui Area;