The Shangfa limestone is a carbonate lenticular that is intercalated in a large suite of Middle Triassic detrital rock. It is a particular sedimentation of varying relief zone near facies change line between platform facies and basin facies. Had been weathered and denuded for a long time before Pretertiary

it remained in higher part of the basement surface

and structurally distributed in syncline groove. The formation of oil and gas pools in Shangfa area is controlled and confined by tectonic

stratigraphic unconformities as well as lithologic characters. Source beds is Nadu Formation of Upper Eocene

reservoir bed is the first member of Shangfa Formation and the covering strata are mudstones and shales in bottom of the Tertiary System. To arrange drilling within higher part of basement surrounded and comfined with the second member of Shangfa Formation are expected to success.