Numerical Simulation on displacement mechanism of fracture-cave reservoir surfactant-Assisted N2 huff and puff in Tahe Oilfield

Some fracture-cave units controlled by single well in fractured-vuggy carbonate reservoirs lack natural energy, which leads to rapid decline of production and recovery.Having applied the N2 huff and puff, Tahe Oilfield has improved their exploitation.However, the effect of N2 injection weakens in the production process.So it is necessary to seek new method for exploitation of fractured-vuggy reservoirs.Combing with the numerical simulation, then analyzing the qualitative and quantitative influences of injection rate, injection concentration of surfactant on the recovery efficiency of isolated fracture-cave units, this paper focuses on the problem of the fractured-vuggy carbonate oil reservoir's low recovery, and also forecasts the effect of the different surfactant-Assisted N2 huff and puff scheme, then presents the best plan in this reservoir condition and acquires the main control factors of the surfactant -assisted N2 huff and puff.