An integrated field model and optimization may play an important role during production because an integrated model may produce comprehensive operational recommendations. An integrated field model combined with optimization presents many technological challenges in terms efficient algorithms to couple models, as well as models with optimization, and sufficient hardware capability to run the complex model. A benchmark case which consists of three different reservoirs that are linked to a surface facility model has been developed. The surface process model interacts with the three reservoir models through the distribution of available produced gas for reinjection into the three reservoirs. The reservoir and surface process variables are optimized in terms of maximizing asset value. The integrated model and corresponding optimization results provide a benchmark that contributes to academic and industrial knowledge on the potential value of joint optimization of the upstream and downstream parts of the production chain. The benchmark should be valuable as a tool for assessing future alternative methods for production chain optimization.