Geologic Features of Ordovician Oi l Control in Akekule Arch.

Akekule arch is located in south side of middle part of Shaya uplift in Tarim basin,in which Ordovician carbonate rocks have a broad prospect for petroleum exploration.However,it is obviously controlled by regional struc-tural setting and reservoir development hence resulted in non-homogeneous oil and gas distribution.Based on analyses of the types,distribution and oil-controlled geologic features and predictions of the effective scale of Ordovician petroleum reservoir,it is considered that some effective reservoirs are developed and reserved in karst,buried hill and serious deformation zone of slope area of southern Akekule arch,and there exist multistage petroleum migration,accu-mulation and forming reservoirs with fair seal conditions,which might be a favorable area for forming a large-scale oil and gas pool.