A novel, low-cost approach to multiphase metering – the process of determining the make-up of crude oil as it’s pumped from the reservoir – has been demonstrated by engineers from Brunel University London
Crude oil is extracted from the Earth as a mixture of oil, gas, water and sand, which is separated and processed, at significant expense and risk, before making its way downstream to be turned into usable products.
Now, a novel new ‘visualisation technique’ has been proposed by scientists that could make the process cheaper, safer and quicker.
“Most of the currently available metering systems have certain limitations and they require test separators, high maintenance cost and human interaction,” said Dr Syed Bukhari, a researcher for Brunel’s College of Engineering, Design and Physical Sciences, who led the research under the guidance of Professor Tassos Karayiannis.
“Therefore, there is a need for an accurate, less expensive and compact system that uses non-invasive and non-intrusive technology.”
Dr Bukhari’s proposed new system, which was first unveiled at the International Conference on Fluid Science and Advanced Flow Systems in January, combines electrical capacitance tomography (ECT) imaging technology with artificial intelligence to quickly determine the contents of pumped crude oil.
“In this technique, two ECT sensors are placed at two different locations in an oil pipeline,” said Dr Bukhari.
“A hybrid technique, based on principal component analysis (PCA) and cluster analysis (CA), is used to evaluate ECT images and to identify the time interval necessary for a specific process condition to be detected by both sensors.
“Once this information is obtained, volumetric flow rate and mass flow rate can be calculated using the cross-sectional area of the pipeline and the average velocity.”
The researchers were able to demonstrate that using their new method - and the error rate of less than five per cent was possible – a figure comparable to current, more expensive, invasive systems.
“It is expected that the proposed device will provide fast, accurate and reliable measurements as well as additional information on flow patterns and flow velocity typically not available with standard flow meters,” said Dr Bukhari.
“This feature will allow the oil and gas companies to increase profitability, safety and operational excellence.”