Remedial Alcoholic Condensate Banking Treatment in Deep Gas Wells in the Sultanate of Oman

Abstract

Abstract One of the most gas production challenges from tight gas reservoirs in the sultanate of Oman is condensate banking. Such a phenomenon usually results in sharp declines in gas and condensate production after reaching the dew point, and becomes more influential in the unconventional and depleted condensate-gas fields. Another challenging aspect is the complex and expensive post-drilling and post-fracturing cleanout due to the high capillary pressures slowing the completion brine flowback. Successful field applications developed with alcohol treatments in deep tight sandstone gas wells have minimized the impact of condensate banking on production in the Sultanate of Oman. Thorough lab testing and screening processes to optimize the formulation of the treatment and maximize the chances of success were conducted prior to taking the application to field implementation. In particular, the solvent type and concentration were selected carefully to avoid any precipitation issues that might arise from incompatibility between the alcohol treatments and the highly saline formation water. In addition, careful HSE planning was required before the field deployment due to the low flash point associated with such treatments. A campaign of 4 field trials was conducted on several gas wells that are impacted by condensate banking. For the condensate banking, the treatments managed to restore the gas production from closed-in wells while increasing the condensate rate by more than 170% and gas rate by more than 220%. These promising results have resulted in planning a wider deployment scope to further test the operational limits of the alcohol treatments and optimize the production from several fields that are impacted by condensate-blockage impairment. Using this alcohol treatment as an alternate to traditional water and condensate blockage remediation has improved efficiencies in time, production and materials. The application provides a more economical means to enhance production in tight gas fields of the Sultanate of Oman.