Model-based feedback control of oil production in oil-rim reservoirs under gas coning conditions
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2018 AACC. In oil-rim reservoirs, oil is typically extracted at constant rate. However, the constant-rate oil production strategy may lead to suboptimal solutions as it does not take into account the process dynamics such as how the gas/oil contact (GOC) near the wellbore dynamically changes with time during oil production. Motivated by this, initially, we present a gas-rate dependent gas/oil ratio model to describe gas coning phenomena. Second, a numerical scheme is developed to describe the spatiotemporal evolution of the GOC height during oil production. Third, a reduced-order model is constructed, which is used to design a Luenberger observer for state estimation. Lastly, the model predictive control theory is applied for the design of a feedback control system to compute the optimal oil production profile that maximizes the Net Present Value (NPV) of oil produced from a well before gas breakthrough. We demonstrate that the proposed control scheme is able to compute the oil production profile before gas breakthrough which has a higher NPV compared to other state-of-the-art oil production strategies including Hasan's control law and the conventional constant-rate oil production strategies.