Flow measurement is critical in oil & gas production operations to measure the oil, gas and water content of producing wells for fiscal allocation, well maintenance, and regulatory reporting. In an Oilfield Technology article, A Sense of What is to Come, Emerson’s Stian Engebretsen, Aurore Plougoulen and Lars Anders Ruden describe technology advancements driving improvements in these flow measurements.
They open highlighting the importance of multiphase flow measurement for applications:
…such as reservoir management, field development, operational control, flow assurance and production allocation.
Technology like the Industrial Internet of Things (IIoT):
…unlocks online production monitoring and allows field operators to monitor their wells and obtain real-time and continuous well information.
While test separators have long been used to measure the individual multiphase components in the produced fluids, the measurements can be made in-situ within the wells and flowlines.
Multiphase flow meters (MPFMs) and virtual flow metering (VFM) can be combined to provide operators with a reliable solution powered by IIoT to estimate the in-situ flow of oil, gas and water within wells and flow lines.
A MPFM is installed directly in the flow trajectory and uses the combined measurements from multiple sensors to estimate the flow rates through the meter. Virtual metering relies more heavily on the mechanistic flow models, but similarly to MPFM, it uses sensor measurements as input to estimate the flow rates – the sensors can be located at different locations throughout the flow trajectory.
IIoT sensor technology has advanced in accuracy and reliability enabling downhole pressure and temperature sensors.
Downhole gauges are important for VFM, as they enable flow models to be matched against the response from downhole to wellhead.
The data from these sensors feed data acquisition systems, which:
…can aggregate hundreds of thousands of data points from oil and gas fields down to second interval sampling. Data acquisition systems are now able to push production data to cloud solutions, an enabling technology for digital transformation.
While two forms of VFM exist—model-based and machine learning (ML) data driven-base exist, the authors focused on model-based VFM. A model is built:
…using the fluid properties and the static model information (well and flow line trajectories, location of equipment and sensors, etc.). The model is then calibrated using available data such as well tests, MPFM, or metered data from separators.
Read the article for more as Stian, Aurore and Lars Anders explain how the VFM can assist, backup and validate the MPFMs and vice versa, and how their flexibility and adaptability is suitable for many different types of production flow profiles. Visit the Multiphase Metering and Oil & Gas industry section on Emerson.com for more on the technologies and solutions to drive safer, more reliable and more efficient operations.