The characteristics of oil secondary migration and its affecting factors in the western |Liaohe depression
Qin Liming1 Zhang Zhihuan1 Huang Min2 Huang Zhilong1 Gao Gang1 Liu Baohong3 Li Jun1 Li Jia1 Li Yanmei1
1.State Key Laboratory of Petroleum Source and Prospecting|China University of Petroleum|Beijing 102249； |2.East China Branch of SINOPEC, Nanjing 210011|3.Exploration and Development Research Institute|Liaohe Oilfield Company|PetroChina|Panjin|Liaoning 124010
In the western Liaohe depression，the oil and gas accumulation zones consisted of multiple phases and reservoir types are mainly caused by the hydrocarbon migrated pathways. Based on the analysis of the carbazoles and correlated parameters in nonhydrocarbons，and the oil fluid inclusions in reservoir，combined with the oil or gas distribution regularity，the secondary migrated characteristics and its effective factors have been researched. In central uplift zone，the concentrations of total carbazoles in oil samples are high and the correlated parameters change a little. The oil bearing fluid inclusions are characterized by irregular shape，strong fluorescent light and linear distribution in the micro factures of the quartzes. So，the oil and gas migrated paths are the EW direction en echelon faults under the movement of slipping and the migrated force were abnormal pore fluid pressure. In slope belts，the content of carbazoles and its parameters changed a lot. The oil bearing fluid inclusions are characterized by regular shapes，strong fluorescent light and planar distribution in the secondary edges of the quartzes. The oil migrated by the finger sandbodies of fan delta front branch channels or braided streams and the migrated forces are hydrodynamic and buoyancy from the sags to the slope belts. In the steep slope belt，the content of carbazoles and its parameters changed. The oil migrated by the TaianDawa fault belts or finger sand bodies and the migrated forces are abnormal pore fluid pressure. In the buried hills，the concentration of carbazoles and its parameters changed a lot. The oil migrated by the unconformable surfaces or foundational faults and the migrated force is mainly abnormal pore fluid pressure. The oil migrated stage is Dongying period and became later from the northeast to the southwest correlating with the generated hydrocarbon history.