Salt precipitation and accumulation in the wellbore is a common phenomenon witnessed in the twilight of gas wells; gas expansion, water evaporation, abrupt changes in pressure and temperature etc. are the main driving forces for its occurrence. Low reservoir pressures helps in water vaporization when quantity of water in gas phase is not high. Reduction in pressure thus causes water vaporization and hence salt accumulation.
The salt precipitation results in obstruction of gas flow in purlieu of wellbore, if the problem is not rectified timely it might cease the wellbore completely resulting in complete loss of production. To restore production frequent wellbore cleanout jobs are required, these cleanout jobs are usually carried out through coiled tubing unit and different liquids are utilize ranging from fresh water, nitrified brine, organic acids etc. These all treatments are expensive and effect well economics.
Few wells in United Energy Pakistan Limited (UEP) were facing salt precipitation problem and not flowing up to their potential rates, regular wellbore clean out jobs carried out but their impressions were not long lasting and salt again accumulated.
In this paper, removal of salt deposition through regular deployment salt sticks on two wells K-1 and T-1 are discussed. In these wells salt sticks are used at different frequencies to overcome salt deposition. Post job results showed improvement in gas rates, gauge cutter runs also confirmed salt deposition is minimized and production is stabilized.