Integrated asset models (IAM) are often necessary to analyze properly the pressure interaction between reservoirs and a constrained surface facility network and to predict the behavior of several fields, which may have different fluid compositions, sharing a common surface facility. In this study, we describe a field development project improvement due to production rate management using a well known approach for coupling a commercial reservoir simulator and a simplified surface network model. The approach technique was tested using a real-based case of two offshore fields, one of gas condensate and the other one of light oil, with a gas production constraint due to the gas pipeline capacity. At present work, the two independent reservoir models were controlled simultaneously by the coupling tool and the well production rates allocated at each iteration by the management algorithm. The coupled system gives a significantly higher oil production and NPV than the standalone simulation did only by well production rate management based on GOR (gas-oil ratio). In thirty years production forecast, considering the surface gas constraint, there was a significant increase on NPV and nearly the same recovery factor. In other words, it was obtained an excellent improvement on the overall project due to revenue anticipation using the well rates from management algorithm.