Non-Intrusive Separator Level Measurement - Towards the First Offshore Pilot

Non-intrusive measurement of level in process vessels such as oil and gas production separators offers opportunities to significantly decrease installation and maintenance costs as well as to increase personnel safety and instrument reliability. This has a positive effect on process efficiency and reduces emissions. Provided the measurement technique can offer insights into levels of solids, emulsion, and foam layers, non-intrusive level measurement could potentially become an enabling technology for additional extensions of asset lifetime. This is because a non-intrusive profiler would be a game-changer for process and production control on assets in operation where retrofitting such an instrument is today prohibitively expensive due to its intrusive character.
A novel non-intrusive level measurement technique that utilizes Guided Elastic Waves (GEW) has shown very promising results in laboratory and pilot scale. This paper describes its development, starting with idea and leading towards the first full-scale trial on an offshore installation. The last experimental results, obtained towards a TRL4 qualification with an operator company, show excellent level detection of solids and liquid levels with virtually no error. Induced liquid flow had no influence on the measurement results and the signal did not drift when the system was left running for a month.
In addition to describing the experimental results and the technology qualification process, this paper also provides some reflections on the prioritization with respect to development and testing in the different stages of the qualification process. The prioritization is based on risk and cost benefit evaluation.