Scale inhibitors are used extensively in the oil and gas industry to provide the level of flow assurance required to maximise safe and economic hydrocarbon production. For both continuous and scale squeeze treatments, residual inhibitor concentrations need to be verified on a continual basis to assure the field operator that the implemented scale management program remains effective. To date, the analytical work required to verify residual inhibitor levels of the majority of scale inhibitor chemistries needs to be carried out onshore in a suitably equipped analytical laboratory. Often the time delay from sample collection to reporting of analytical results introduces a significant level of uncertainty with regard to effective scale control which, if removed, would substantially improves the production assurance and safety of the facility operations.

The KARMA system is a point-of-use measurement platform that measures the residual concentration of typical polymeric scale inhibitors in produced water providing a timely and accurate residual scale inhibitor concentration to the facility operator. After initial basic training, the analysis procedure can be carried out at the production location where the sample is taken, with the result obtained and recorded with 30 mins. The analysis method is unaffected by either the presence of other production chemicals or by the variation in typical North Sea produced water composition.

The measurement system utilises the Aqsens aqueous liquid fingerprinting technology platform and is applicable to a wide range of polymer chemistries; a specific polymer tag/label is not necessary. Unlike other systems, the analytical method is not based on immunoassay detection technology that requires modification to scale inhibitor formulation to include tagged polymer-specific antibodies. We have deliberately reverse engineered this for a range of current scale inhibitor products to provide direct field analysis to customers on either continuous or scale squeeze application programs.

The system derives its sensitivity by combining time-resolved fluorescence with optimised chemistries to quantify the polymer levels. Performance results from laboratory testing and on site testing at an oil recovery facility will be presented.