Environmental problems, although nettlesome and often costly, have served to stimulate new developments in drilling fluid technologies. Minimizing environmental impact involves reducing levels of toxic components in drilling fluids, as well as waste minimization and recycling. Significant progress is being made. This paper assesses the current state of technology and the likely directions for the future. The constructive role of regulatory agencies in recognizing, fostering, and encouraging the use of emerging technologies, as opposed to blanket prohibitions, also is discussed.
Mud companies have identified replacements for diesel and mineral oils in lubricants and spotting fluids that combine performance and environmental acceptability. Non-chloride potassium sources have replaced KCI in many water-based muds. New cationic polymer muds are being touted as replacements for oil-based muds in many situations, and preliminary field results are encouraging.
The trend to polymer muds, in general, has reduced consumption of traditional lignosulfonate additives and other organo-metallic complexes. Weighting agents also have been affected. Barite ore sources are scrutinized carefully for their trace heavy metal content with particular attention to cadmium and mercury impurities.
