Well production characteristics and control factor analysis of
Guangan gas field in Sichuan Basin|southwestern China
Lan Chaoli1 Wang Jinxiu2,3 He Shunli1 Yang Minghui2,3 Zhang Junfeng4
1.MOE Key Laboratory of Petroleum Engineering in China University of Petroleum|Beijing 102249；
2.State Key Laboratory for Petroleum Resources and Prospecting|China University of Petroleum|Beijing 102249；
3.Faculty of Natural Resources and Information Technology|China University of Petroleum|Beijing 102249；
4.PetroChina Company Limited|Beijing 100001）
The exploitation and development target are the sixth and fourth Members of Upper Triassic Xujiahe Formation in Guangan gasfield of Sichuan Basin，southwestern China. The reservoir sandstones of these two members are deposits of deltaic distributary channels，underwater distributary channels and mouth bars and have typically low porosity(mainly 6％〖KG-*5〗～12％)and low permeability(mostly 01×10-3 μm2～10×10-3μm2)with rare fractures. The gas reservoir distribution is controlled by structure and/or lithology. Accordingly，the reservoir types include structural，lithological and structurallithological ones. To offer guidance for next well location and producing capacity of this gas field，production characteristics were investigated based on well test data. The well productivities can be subdivided in four types(Ⅰ， Ⅱ， Ⅲ and Ⅳ)and seven subtypes(Ⅱ1， Ⅱ2， Ⅲ1， Ⅲ2， Ⅲ3， Ⅳ1 and Ⅳ2)，and change greatly among these types. Every type has different water production. Of which，typeⅠ，subtype Ⅱ1 and Ⅲ1 have more enough or stable producing capacity. Factors controlling well production were explored. It can be concluded that sedimentary facies，well dynamic reserves，elevations，water productions and technological measures have important impacts on gas well production. When the wells were drilled in the high energetic distributary channel，underwater distributary channel and mouth bar zones，they would achieve higher productivities if they have bigger well dynamic reserves，higher elevations，smaller water production and more proper fracture and protection technologies.