Synergy in Maximizing Value on Deepwater Development: Employing Fluid Sampling and Subsea Processing

摘要

The acquisition of accurate subsea fluid samples for deep and ultra-deepwater development is crucial for the correct evaluation of oil reserves. This would enable design optimisation of subsea production and processing facilities in order to maximize asset value. Obtaining fluid samples from actual flow stream being measured subsea is one of the operational requirements to acquire accurate measurement for calibration of Subsea Multiphase Flowmeter (SMPFM). To achieve this, sufficient sample volumes are collected through Remote Operated Vehicle (ROV) deployed fluid sampling to ensure statistically valid characterisation of the sampled fluids. A virtual fluid sampling model has been developed, using the fluid properties that are equivalent to the flow stream being measured, to predict reliable reservoir fluid characteristics. This is applicable even under conditions where significant variations in the reservoir fluid composition occur in transient production operations. Another benefit is the value it adds in deciding when to employ subsea processing to manage water breakthrough as the field matures. This can be achieved through efficient processing of the fluid delivered to the topside facilities or for water re-injection to the reservoir. The failure to obtain representative samples can have considerable impact on the Operational Expenditure (OPEX) and consequently the asset value to sustain production volume or enhance financial returns over the life of the field. Hence, the virtual model provide a predictive tool to mitigate the risk of obtaining unrepresentative samples from measurement instruments in the field, with considerable cost saving on intervention of subsea sampling operations. Therefore, the combination of SMPFM, ROV deployed fluid sampling system and the virtual fluid sampling model, provides a balanced approach for reservoir performance monitoring. The present paper explores the synergy in successful application of subsea fluid sampling to maximize asset value in implementing subsea processing on deep and ultra-deepwater development.