Remote technology to determine if waste water from oil extraction is contaminated, could avoid time-consuming lab tests.
“Produced water” extracted alongside fossil fuels is a sizeable by-product of the oil and gas industry – modern oil wells produce as much as 10 barrels of water for each barrel of oil – and treating and disposing of this water is a major expense for many operators, with production sometimes limited by how much water can be handled.
This water is often re-injected into the wells, but any contaminants can do irreversible damage to the production process. Currently, produced water quality is usually assessed by samples being sent for time-consuming laboratory analysis meaning it may be too late by the time any issues are identified.
But new particle analysis technology created by product development firm Cambridge Consultants can measure droplets of oil or particles of sand and wax in produced water in real-time at offshore sites, giving an immediate indication of whether the water can be safely reinjected into a well or disposed of overboard.
“There is a general need to be able to check for the levels of sand, oil and additives in produced water that is to be reinjected into the well,” said Dr Frances Metcalfe, associate director, oil and gas, at Cambridge Consultants.
“If a well exceeds certain limits, for example due to a failure in processing equipment, particulates can block pores in the rock, causing production to stop and even render the well beyond economic use.
“There is therefore a real need to be able to analyse very tiny droplets and particles in a pipeline in real-time in order to speed up reaction time to correct potential issues.”
The patented technology uses a combination of optical measurements and signal processing techniques to measure the size distribution of droplets ranging from sub-micron to tens of microns in diameter at typical production flow velocities.
The technology uses hardware that lends itself to being deployed online in remote locations and from there, the results can be sent directly to an operator to allow remedial action to be taken before a situation becomes critical.
In the future, such a system could also include a local alarm that would flag up a potential problem and send a control signal to fix an issue or turn off a valve. Potential applications include wet gas, produced water and polymer flooding, MEG injection or scale monitoring.
The Cambridge Consultants oil and gas team will be available to discuss the new particle detection technology at the SPE Offshore Europe Conference and Exhibition, 3 to 6 September, in Aberdeen.