Shunnan-Gucheng region is located at the convergence of three structural units: Shuntuoguole Low Uplift (Aman low Uplift)

Katake Uplift (Tazhong Uplift) and Guchengxu Uplift (Gucheng Low Uplift)

in Tarim Basin. In recent years

gas flows have been tested in 11 exploratory wells drilled into the carbonate reservoirs in the Middle-Lower Odovician Yingshan Fm. or the Middle Odovician Yijianfang Fm. -Middle-Lower Odovician Yingshan Fm. (mainly the Yingshan Fm.)in Shunnan-Gucheng region and the Lower Cambrian Xiaoerbulake Fm. in the Tazhong No. 1 Structure of the basin. Among the 11 wells

the well Shunan-5 and Gucheng-9 tested the highest flow rate of 165. 8×10

4

m

3

/d (open flow)and 107. 8×10

4

m

3

/d

respectively

showing great gas potential in Shunnan-Gucheng region. Composition analyses of hydrocarbon and stable carbon isotopes of gas samples from 11 wells in Shunnan-Gucheng region and Tazhong No. 1 Structure indicate an over-matured dry gas

with dry coefficient between 0. 99 and 1. 00 and carbon isotopic values (δ

13

C

1

-δ

13

C

4

) bigger than-42. 5‰. Correlation with the typical gas samples with different sources in Tarim Basin reveals that the gas in Shunnan-Gucheng region originated from source rocks in the Cambrian. Combining fluid inclusion microthermometry with single well numerical modeling of stratigraphic burial as well as thermal histories and measurement of vitrinite reflectance R

o

profile on samples from Well Shunnan-4

we determined that the studied gas reservoirs were typical late-stage gas accumulations with gas-charging occuring druing the Miocene (22-10 Ma).