Virtual Flow Metering Of Oil Wells For A Pre-Salt Field

The flow rate values reported in real time, for an oil and gas production unit, refer to the total amount produced by that unit. On the other hand, data referring to the flow rate of each producing well in real time are usually not available, due to the difficulty in implementing flow measurement devices. These individual flows are determined by production tests that are generally performed every two months and are important for production planning and optimization. Therefore, there is a need to generate models capable of predicting the flow of each well in the period between tests, in order to identify possible issues during the production. In this context, we propose in this paper a method to predict the liquid and gas flow rates of each well as function of measured variables available in plant data collected in real time. Choke valve specifications and fluid properties are also required as model input data. Since there is no flow measurement device, it is not possible to directly validate the model results against plant data. In this case, the model validation is performed using the total liquid and gas flow rates presented in the Daily Operation Report (DOR) and those provided by fiscal meters. Relative errors below 3.5% were observed, showing good agreement between the calculated flow rates and the provided by fiscal meters. The proposed method was implemented in the computational environment EMSO, which presents as advantages the low simulation time and robustness over a wide range of input data. These advantages become important as the model is used for monitoring platforms in real time. The range of applicability of this model can be attributed to the Gas-Oil Rate (GOR). In this work, the lowest and highest values of GOR considering all the wells are 207.58 and 393.97, respectively.