Barium sulfate, a common oil-field scale, continues to be a key challenge for many E&P companies operating offshore, especially in the Gulf of Mexico. Barium sulfate can form from the mixture of two incompatible fluids, such as sulfate containing sea water and formation water containing barium ions. Barium sulfate is not acid soluble and is very hard regardless of where it forms, be it the tubulars or in the pore space of the formation matrix. It causes formation damage, hosts bacteria, fouls piping, tanks and process equipment, thereby reducing production and profitability.
Dissolving barium sulfate scale in the tubulars with 1mm of thickness in a 6-inch casing, requires that a dissolver have a removal capacity of 40 g/L.1 Common industry dissolvers have removal capacities less than 40 g/L. The dissolver removal capacity is further impacted by temperature and soak time.
Tendeka offers the high performing barium sulfate dissolver, Enviro-Syn-BSD-40, which is strong chelating-based chemistry that is non-corrosive to metal or typical oilfield elastomers and seals. It has a low pH profile (10.5 – 11) compared to other dissolvers, making exposure less of a risk to personnel. It has a high thermal stability of 270°F and has dissolution capability at temperatures as low as 104°F.
The removal capacity of BSD-40 when tested with lab grade barium sulfate at 158°F for four hours was 52.72 g/L. Extensive dissolution testing with scale samples from the GOM have been conducted showing high removal capacity at both low and high temperatures compared to other leading industry barium sulfate dissolvers.