Radiochemical characterization of produced water from two production offshore oilfields in Ghana

• Concentrations of 40K, 238U and 232Th-series isotopes have been determined in produced water by alpha and gamma spectrometry.
• The 226Ra and 228Ra concentrations obtained in this study for produced water are of radiological importance.
• A good linear correlation was observed for 226Ra with most physico-chemical parameters.
• This study serves as a baseline for information or further research.

Produced water from two Ghanaian offshore production oilfields has been characterized using alpha spectrometry after radiochemical separation, non-destructive gamma spectrometry and ICP-MS and other complimentary analytical tools. The measured concentrations of main NORM components were in the range of 6.2–22.3 Bq.L−1, 6.4–35.5 Bq.L−1, and 0.7–7.0 Bq.L−1 for 226Ra, 228Ra and 224Ra respectively. A good correlation between several physico-chemical parameters and radium isotopes was observed in each production oilfield. The radium concentrations obtained in this study for produced water from the two oilfields of Ghana are of radiological importance and hence there may be the need to put in place measures for future contamination concerns due to their bioavailability in the media and bioaccumulation characteristics. The results will assist in critical decision making for future set up of appropriate national guidelines for the management of NORM waste from the emerging oil and gas industry in Ghana.