An implementable zone NMPC applied to an ESP-lifted oil well system: Handling the lack of measurements with nonlinear state estimator coupling

Embedded MPC Strategies for ESP-Lifted Oil Wells: Hardware-in-the-Loop Performance Analysis of Nonlinear and Robust Techniques

“…In contrast, Santana et al [17] presented a zone NMPC formulation that can handle these limitations for ESP-lifted oil-well systems. Their approach explicitly deals with ESP operational envelope constraints via an implementable zone-control scheme.…”

“…The main contribution of this work is the proposition and systematic analysis of an embedded robust MPC strategy for ESP-lifted oil-well systems from the preceding discussion, not yet documented in the E&P literature. Through a hardware-in-the-loop simulation, its performance is compared against the NMPC scheme proposed by [17]. Both strategies encapsulate the zone-control approach to deal directly with the ESP operational envelope constraints and incorporate economic targets to improve their performance.…”

“…This section presents the NMPC approach for ESP systems proposed by Santana et al [17]: a zone control approach incorporating the model ( 1)-( 4), resulting in a soft optimization problem. In this sense, the constraints of the zone map the operational envelope, as presented in Figure 2, which avoids infeasible solutions for the optimization problem.…”

“…In this sense, the constraints of the zone map the operational envelope, as presented in Figure 2, which avoids infeasible solutions for the optimization problem. The optimization problem is given by [17]:…”

“…y sp,k is the artificial setpoint within the proposed zone-control scheme and is a decision variable in the Problem 1; u tg is the optimizing target of the manipulated variables; u max , u min , ∆u max , are the constraints on manipulated variables and their increments, respectively. y max (k|k) and y min (k|k) are the upper and lower bounds of the zone control included in constraint (10), evaluated from the operational envelope according to [17]. p and m are the prediction and control horizons, respectively; Q y , R and Q u are weighting matrices on controlled, control actions and manipulated variables, respectively.…”