Control effect of fault condensed belts in hydrocarbon accumulation in slope area outside of source area: A case study of Fuyu oil layer in Zhaoyuannan region, Songliao Basin

By using the results about fine structure interpretation,reservoir prediction and sublayer sedimentary microfacies,development characteristics of faults and their control to the deposition of Fuyu oil layer in Zhaoyuannan region were discussed,and then control effect of fault condensed belts in hydrocarbon accumulation was researched with the distribution of oil and water in Zhaoyuannan region.The results show that faults of Fuyu oil layer are made up of middle and long-term faults,and there are eight condensed belts in the plane by the control of basement faults.When hydrocarbons in source rocks are generated and then expelled,the NNW-trending faults were reactivated in eastern fault condensed belts,while only faults were reactivated in the western.By the control of basement and long-term growth faults,there are two spatial combinations between western fault condensed belts and distributary channel: high-angle intersection or distributary channel’s long-distance extension along fault condensed belts in the upside of faults,while the spatial combinations between eastern fault condensed belts and distributary channel is low-angle intersection.The oil in Fuyang layers,Sanzhao Depression migrates laterally to Zhaoyuannan region along the fault condensed belts connected by sand bodies with the buoyancy force and then accumulated in fault block,and fault-lithologic traps besides fault condenses belts.Hydrocarbon migration and accumulation in fault condensed belts is controlled by fault activity and spatial combinations between fault condensed belts and distributary channel: In eastern fault-sand system is formed by reactive faults and distributary channel,and fault block within,fault-lithologic traps besides fault condensed belts are both accumulated by oil;In western boundary fault-sand transporting ridge is formed in the upside of faults of condensed belts,and the oiliness becomes gradually poor from fault-lithologic traps besides to fault block within fault condensed belts.