Iran is considered as one of the biggest burners of associated gas. Due to the importance of reducing the emission of pollutants from associated gas in flare systems, in this study we use advanced decision-making methods to select the optimal technologies for recycling associated gases that are currently burnt. The model has three objective functions, including minimum return on investment and maximum reduction in carbon dioxide emissions and qualitative target functions considering a combination of sustainable development criteria. In the developed model, we assess important flared gas recovery technologies including NGL units, gas injection into pipeline, LNG units, GTL refinery units, production of gas hydrates (NGH), CNG units, injection of gas into reservoirs to increase oil production ( EOR), electricity generation using gas turbines, steam turbines and combined cycle and fresh water production. Our sample includes five oil wells in an oil region in southern Iran. The results show that in the optimal case, the investment undetakes pays for itself in 1. 1 years and produces a reduction of 810740 tons of carbon dioxide per year.