Assessment of Barium Sulfate Scaling in Conventional Gas Well Production using Real-Time Monitoring

摘要

Scaling has been a major concern in a conventional gas condensate well production facility in northwest Louisiana. Severe barium sulfate deposits have been noted throughout the facility causing operational issues resulting in increased lifting costs. The production is primarily from two formations, the Cotton Valley and Hosston. The Hosston has relatively high sulfate while the Cotton Valley has relatively high barium. Combining these waters creates a barium sulfate scaling environment similar to worst case North Sea or Gulf of Mexico examples. The applications of a bench-top scale deposition monitor as well as a real-time monitor are described. The use of both techniques is illustrated by presenting results of field testing performed at location to get a better understanding of the severity of the scaling problem as well as the treatment rate of scale inhibitor necessary to control scaling. The rate of scaling was determined for the Hosston and Cotton Valley waters, independent of each other and also as mixtures of the two, using the bench-top monitoring technique. The rate of scaling of the combination of the waters was an order of magnitude greater than either of the waters by themselves. The inhibitor dosage required to inhibit scale was also determined and reported for each water condition. Real-time monitoring was conducted in the facility at a point just prior to water disposal. The results obtained to date agreed with the bench-top monitor results. Inhibitor treatment is currently being adjusted based on real-time monitoring to optimize field treatment and further validate the bench-top method.