Optimizing Operations Sequencing and Demulsifier Injection in Offshore Oil Production Platforms

Abstract

Short-term production optimization of oil assets concerns routing decisions and equipment control settings that induce optimal steady-state operations. Typically, the decisions are made on the scale of hours to days with the aim of maximizing short-term economic and oil gains. Still an evolving field, this paper contributes by presenting a model and solution strategy for sequencing operations over time to drive the system towards an optimal state, while accounting for constraints that ensure smooth transitions until settling at the terminal steady-state. The constraints include the maximum number of wells that undergo a change in the control settings, maximum number and variation on the input signals for each well, and maximum number of changes in each time period, among others. Additionally, the proposed strategy can optimize the rate of injection of demulsifiers into wells considering the limits and impacts on fluid processing capacity. The paper reports simulated results for a real-world offshore production platform, demonstrating the effectiveness of the optimization strategy to cope with the failure and recovery of compression capacity, and to manage the injection of demulsifiers. The experiments show a gain of 11.5% in total oil production resulting from an optimal management of demulsifiers.

Keywords

• Production optimization
• operations sequencing
• demulsifier injection
• nonlinear optimization
• piecewise-linear approximation