Natural gas geochemical study of the Hetianhe gas field in Tarim basin

Abstract：This paper has analyzed the natural gas components, carbon isotope composition and natural gas genetic types of the Hetianhe gas field, with the emphasis placed on the differences between the eastern part and the western part. Studies show that methane content of the natural gas is extremely high, mainly in the range of 64.19%～86.86%，being 79.36% on average; C2+ content is 0～3.75%; the dry coefficients vary in the range of 95.52～99.4，97.34 on average; CO2 content is high. There exists remarkable difference in natural gas conditions between the eastern part and the western part, resulting mainly from multi-period accumulation, reaction of TSR and westward migration. As for the genesis of the natural gas, there are oil-cracked gases in the eastern part, with the Ma 2 well being mixed gases of the oil-cracked gases and the kerogen-cracked gases, whereas kerogen-gases are dominant in the western part.