Apache has developed a number of small oil fields using unmanned minimum facilities platforms close to Varanus Island, on the North West Shelf of Western Australia. Production from each platform is commingled into a single production trunkline. Wells producing at high watercut are artificially lifted using gaslift. Production monitoring and well allocation uses multi-phase flow meters situated on each platform. The use of these meters minimises total infrastructure cost, while still allowing the direct testing of each well. Test results are used for production optimisation of the individual wells, optimisation of the integrated production network, well and field production allocation and troubleshooting. Meter performance has been satisfactory, resulting in an additional unit being deployed on the Stag field where production is affected by high gas rates, slugging and sand production.
Accuracy aspects in multi-phase flow metering using X-ray transmission
