Sensitivity Analysis and Multiobjective Optimization of CO2 Huff-N-Puff Process after Water Flooding in Natural Fractured Tight Oil Reservoirs

The CO2 huff-n-puff is an effective substitute technology to further improve oil recovery of natural fractured tight reservoirs after water flooding, for its high displacement efficiency and superior injectivity. process influenced by many factors, such as miscible degree, complex fracture networks, production schemes. What worse, those influence facts affect each other making the more complex. Many researchers concentrated on mechanisms single sensitivity analysis process, whereas few optimized this with consideration all factors multiobjective get favorable performance. We built consisted recovery, gas replacing rate considering aspects flooding special characteristic, technical effectiveness, economic feasibility, respectively. have taken Yuan 284 block a case, firstly investigated analysis, then using orthogonal experiment design multifactors multiobjectives. optimization results show can significantly 8.87% original in place (OOIP) compared which offers guidelines field operations.