Study On Huff And Puff Process For Enhanced Oil Recovery Using CO₂,N₂ And H₂O

Over the last couple of years,the trends in the world hydrocarbon reserves discovery have been in decline.Searching for new hydrocarbon deposits has shifted to difficult terrain such as deep water,environmentally sensitive areas like the arctic,and recently to unconventional resources like shale and tight sand oil and gas which require higher investment for field development.In addition,the recent decline in oil prices coupled with the ever increasing demand for energy around the world has been a concern for both governments and the energy companies to sustain the world's energy demands.The main objective of this thesis is to increase oil productivity from those complex faulted black reservoirs,for which huff and puff simulation will be a viable alternative to primary production.These beg the question how we can economically sustain hydrocarbon production from mature fields,especially for those complex faulted block reservoirs.The areas of these reservoirs are often small,and in most cases are completed with only a signal well.These reservoirs are closed by faults and without external energy supply.Thus,it leads to a quick decline in reservoir pressure during primary production,which results in fast declines of oil rate.To solve these problems,this thesis investigates the huff and puff technology to enhance oil recovery by injecting water or nitrogen or CO2.Reservoir simulation is applied to study the performance of the technology and the associated reservoir pressure decline in the complex reservoir.The different injection fluids in huff and puff process are studied in the faulted block reservoir.The simulation method is used to evaluate the oil recovery using gas and water as the injection fluid.Sensitivity analysis is conducted to rank the huff-and puff parameters that contribute to oil recovery,and then the optimization is carried out to determine the optimum injecting rate and the optimum soaking period as well as optimum production time using the various injection fluids.The results of the simulation show that the gas injection huff and puff can recover more oil than water injection huff and puff.