Tackling Mixed Scales Issue in Oilfield Using a Novel Robust Scale Dissolver

Abstract

Abstract The scale problem is turning into a fluid-related flow assurance concern in oil and gas wells at various locations in the Malaysian basin. Flow assurance issues can have a severe influence on the total fluid production trip from subsurface to surface. Oilfield scale comes in different varieties, including organic, inorganic, gas, soap, and mixed scales. In the past, there was only one type of scale dissolver chemical that could be used, making it less efficient to dissolve multiple types of scales at once. The evaluation of a recently developed, so-called robust solid dissolver (RSD), from the lab to a pilot deployment, is presented in this work. The RSD technology was developed based on a stable micro-emulsion solution that comprises acid and solvent components. Near the wellbore and along the tubing string of an oil well, it can concurrently dissolve organic and inorganic scales. After extensive visual analysis and laboratory experimentation, it was determined that the mixed scales issue was the cause of the oil production's rapid decline. This conclusion was supported by laboratory analysis and observations made from the wellsite throughout the tubing string and near wellbore casing. Based on laboratory tests, RSD can dissolve mixed scales 100% in 24 hours at well temperature and no incompatibility issue with production chemicals and all the pumping/wireline components. The RSD was developed based on the total organic system that can prevent corrosion, is compatible with hydrocarbon. The RSD was piloted at oil well "1" at Field PN and executed successfully to remove mixed scales and the well was revived. Based on result from the first Pilot, it revived oil well, increased production at a certain level. By increasing oil production rate and having value creation as a single chemical treatment to address mixed scales concerns, the new RSD has unlocked its potential to revive the well due to mixed scale issues.