Investigation on the Suitability of Virtual Flow Metering System as an Alternative to the Conventional Physical Flow Meter

Abstract

Abstract The interest in Virtual Flow Metering (VFM) has been increasing as awareness of its capabilities and benefits as an alternative or backup to the conventional physical flow meters evolves. Despite the fact that the technology has been in operation for more than 20 years, the adoption of this metering technology remains slow, particularly in Asia Pacific region. Virtual flow metering system provides real-time production monitoring of wells. A fine-tuned model and sufficient well instrumentation can also detect water breakthrough in the gas production well or gas coning in an oil producer. The main objective of this paper is to improve the general understanding of virtual flow metering technology and provide a basis to evaluate if implementation of VFM is a suitable alternative to conventional physical flow metering for a given system. The VFM technology is based on an online (real-time) steady state multiphase flow simulator (thermo-hydraulic models) of the field, where flowrates are estimated using a powerful multivariable optimization solver. For individual wells, the model typically includes the production system from reservoir up to commingling point, e.g. manifold. Successful utilization of virtual flow metering technology is dependent on the availability and accuracy of instrumentation. Model tuning also plays a critical role in a VFM system as it is required to compensate for changes in the system and fluid characteristics throughout the life of field. This paper exemplifies a case study to show how the accuracy of VFM might change over time and the importance of performing model tuning regularly.