Nuclear magnetic resonance multiphase flowmeters: Current status and future prospects

Multiphase flowmetering is a requirement across a range of process industries, particularly those that pertain to oil and gas. Generally, both the composition and individual phase velocities are required; this results in a complex measurement task made more acute by the prevalence of turbulent flow and a variety of flow regimes. In the current review, the main technical options to meet this metrology are outlined and used to provide context for the main focus on the use of nuclear magnetic resonance (NMR) technology for multiphase flowmetering. Relevant fundamentals of NMR are detailed as is their exploitation to quantify flow composition and individual phase velocities for multiphase flow. The review then proceeds to detail three NMR multiphase flowmeter (MPFM) apparatus and concludes with a consideration of future challenges and prospects for the technology.