Tectonic impacts on hydrocarbon accumulation in Laizhouwan sag

By analyzing tectonic activities,hydrocarbon source-reservoir-seal associations and crude geochemistry in Laizhouwan sag,it is considered that the main tectonic events to control hydrocarbon accumulation are Himalayan movement and Tanlu Fault activity.As a result of Late Paleogene uplifting by Himalayan movement,a shale seal on the top of Dongying Formation in Laizhouwan sag was eroded,and early-formed lower oil accumulations in Paleogene suffered severe biodegradation due to their shallowing and the effective seal thinning.Tanlu Fault activities played an important role in structure development, sedimentation and upper hydrocarbon accumulations in Neogene in this area,but the strike-slip faults were harmful to hydrocarbon migration.The occurrence relationship between stratum and faults has controlled locations of upper hydrocarbon accumulation in Neogene.