Optimiser: automated design and optimisation of CSG and water gathering systems

Abstract

The capital-intensive nature of CSG upstream-gathering systems and the need to optimise the cost of the facilities in this industry place great focus on their cost optimisation by operating companies and design contractors. CSG-gathering networks present an ideal opportunity for design optimisation as they are highly branched, consisting of tens or hundreds of individual pipeline segments between nodes, with a wide range of available pipeline sizes. Determination of line sizes in these complex systems is not intuitive; analytical methods of line size selection is time consuming and cannot guarantee that the most cost-effective permutation of line sizes is selected. This extended abstract presents a software tool developed by Fluor that automates the hydraulic design of the CSG and water-gathering systems and determines the optimal set of line sizes based on capital cost for almost any network-routing configuration. Monte Carlo analysis is used to model the uncertainty associated with gas and water production rates and a genetic algorithm is implemented to determine the set of gathering system line sizes that provide the maximum gas and associated water deliverability for the minimum installed cost. This tool is both fast and robust, and has been proven through its application on a major CSG development project in eastern Australia. The tool is also highly flexible; it can be tailored to project specific requirements, conditions, and inputs; and, it can be applied to networks other than CSG with similar challenges.