Reservoir Simulation Study OfAir Injection In Block Hu12

Air injection into light oil reservoirs is a novel technology, which can be used forsecondary and tertiary recovery. Oxygen can be consumed via a low temperature oxidation(LTO) process in the reservoir to generate flue gas flooding. In this thesis, numerical modelsof air injection LTO process were summarized and analyzed to provide theoretical basis forthe reservoir simulation of air injection. For the crude oil in Block Hu12 of Zhongyuanoilfield, LTO kinetics parameters were determined by oxidation experiments at static and flowconditions and modified via up-scaling in numerical simulation. The variations of temperature,gas entrainment and oil properties after LTO were analyzed by using the conceptual model,and the characteristics of air injection LTO process were shown. Sensitivity studies have beencarried out to provide reference for preliminary reservoir screening and project design,including sedimentation type, completion method, dip angle, gas injection rate, gas-waterratio and alternation cycle. For field applications of air injection, geological and dynamicproduction models of the Middle SaSan 8^6-8 Unit in the Hu12 Block have been established,and history matching of the previous waterflooding was carried out to verify the models. Airinjection to exploit remaining oil was studied by using the established LTO kinetics andreservoir models, in which different operation schemes were compared. For the reservoirwhich has a bad waterflooding effect and closely-packed passages with high permeability, gasbreakthrough was delayed and swept volume was increased by water alternating gas (WAG)injection.The results show that WAG displacement process can enhance recovery by 4～7%compared with waterflooding process, and more well,the better effect. The optimal gas-waterratio was 2:1 and the optimal alternation slug was one years. The shorter alternation cycle, thebetter effect. Safety was confirmed by the oxygen distribiution of the typical scheme. Theresults can provide references for engineer to establish air injection scheme.