A NEW CONCEPT FOR SIMULTANEOUS REDUCTION OF ALKALINITY, OIL AND UNDESIRABLE GASES SUCH AS CO2 AND H2S

摘要

In a steam assisted gravity drain (SAGD) application to extract oil from the reservoir, lime softening is often utilized to reduce the hardness and silica concentration to meet feed water quality requirements for 'wet steam generators'. Produced water is normally treated for recycle and reuse as feed water to the steam generator. When the produced water contains a high alkalinity concentration, the lime softening reaction will produce excessive volume of 'wet' sludge resulting in large capital cost for sludge dewatering, handling and disposal. This paper presents a method to reduce alkalinity concentration in produced water without excessive sludge production and discusses stripping CO2 produced from the chemical reaction. Free oil removal by induced gas flotation (IGF) is well documented, so no discussion of oil removal is presented here since the new concept focuses on the improvement of IGF to achieve the above mentioned objectives.