| Title | DEVELOPMENT OF A SYNERGISTIC BLEND OF CORROSION INHIBITORS FOR ACID CLEANING |
|---|---|
| Authors | M.A. Todd, L. Muller |
| Year | 2018 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | Corrosion inhibitor, acid cleaning, well rejuvenation |
| Abstract | Mineral scale, such as calcite, can build up on the walls of production wells when calcite inhibition is not used or is poorly designed or managed. When this occurs, flow is restricted leading to reduced efficiency or possibly complete loss of production. Scaled wells can be cleaned using acids such as hydrochloric acid. While acids are great for dissolving scale, they are very aggressive to the underlying metal. Corrosion inhibitors are used to prevent damage to the metal during acid cleaning. A synergistic blend of inhibitors was developed which provide corrosion protection for well rejuvenation with hydrochloric acid. Initial screening began with jar tests at 95 oC and 15% hydrochloric acid. The most promising candidates were blended together and reevaluated. A combination of inhibitors provided superior protection to the individual inhibitors alone. Subsequent tests in 10% HCl at 150 oC showed that a formulation provided excellent protection even at higher temperatures. |