Lab Study Of Nitrogen Injection EOR On Ultra-low Permeability Reservior

At present our country each big oilfield has come to develop the mid-late, want to realize and stable yield must seek development with low permeability reservoir, the effective method through osmosis, therefore, FanChuan blocks with complicated oilfield as the research object. This block is representative of ordos basin extra-low permeable reservoir, this paper adopts the system theory analysis and a lot of indoor experiments, in this block reservoir characteristics and fluid characteristics, studied, and nitrogen flooding according to enhance oil recovery mechanism and crude oil and nitrogen high-pressure property analysis points out, FanChuan block oil complicated implementation of low permeability reservoirs, nitrogen flooding is feasible. Through the pure water flooding and indoor core chemical water flooding, pure nitrogen flooding, water nitrogen alternate flooding, chemical water nitrogen alternate flooding and water nitrogen alternate flooding after alternating water flooding nitrogen chemical changes of the ultimate recovery, analyzes the above several changes in the way multi-gas recovery; And through indoor experiments of nitrogen foam flooding foam agents formula of several foam screening, through different concentrations foaming agent in the quantities and half-life, optimal screening experiment the best foaming agent and foaming concentration; Through the indoor core in three gas to liquid ratio of the influence of the recovery, the optimum nitrogen foam liquid alternate flooding, and best gas to liquid ratio of water flooding the core extracted after nitrogen foam flooding, analysis the change. Recovery...