Analysis of Optimal Control Strategies for Efficient Operation of a Produced Water Reinjection Facility for Mature Fields

Abstract

Produced water management policies in oil and gas industry have been moving towards zero emission, no ocean discharge and waste-to-value conversion. Produced water reinjection plays a key role in achieving these goals for mature fields as it derives value from produced water and is able to maintain environmental integrity. A central element in this, is optimal operation of pumping. Hydraulic efficiency and specific energy are generally the chosen indices used to evaluate operational energy efficiency in pumping systems. In this work, we investigate optimization strategies based on natural objective function candidates for a produced water reinjection system: (i) operation at best efficiency point; (ii) minimization of total shaft input power; (iii) maximization of overall pump hydraulic efficiency; (iv) minimization of total specific energy and (v) minimization of total delivered energy. In addition, we discuss the implication of the different solutions over control structure selection.