Architecture and Implementation of an Optimization Decision Support System

This paper describes the implementation of an optimization advisory system by Sarawak Shell Bhd. on the integrated gas production system in Sarawak, to help monitor and optimize in real-time the more than 100 wells on 30+ facilities of the system, governed by different Production Sharing Contracts. We highlight how multiple disciplines are part of the solution, how the solution has been embedded to provide real-time advisory to planners and operators, and the challenges faced. The technology described in this paper provides real-time advisory on flow rates for individual wells and platforms to network coordination operators to achieve a gas supply that meets overall gas demand for the onshore LNG plants, maximizes revenue from condensates production and CO2 blending, and transparently shows the business value impact of giving preference to short- or long-term optimization objectives. It takes into account existing commercial and contractual constraints, as well as financial and economical elements. The optimization approach is data-driven and features multiple, mutually dependent objectives and constraints. The data-driven approach has proven significantly faster and more practicable than prior physical model-based approaches. Field trials have proven a condensate production increase of up to 7,000bbl/d while at the same time improving Ultimate Recovery of the sweet and sour gas blend of the production system by up to 2 months per ‘year of applied optimizer advise’. At the same time, gas nominations are met as they were, and commercial and quality constraints are adhered to. The Return On Investment of this solution has been less than a month. This is one of the first successful attempts to implement truly-real-time optimization in a production environment of this size and complexity, including a complicated set of commercial and contractual constraints. The approach opens the door to application to a wide variety of real, complex, mixed-integer non-linear optimization problems, and their organizational application, such as emissions management and decision support systems for integrated IOR/EOR systems.