Paper: SODIUM SILICATE AS A TREATMENT OPTION FOR CASING REPAIR AND CONFORMANCE

Sodium silicate has a long but somewhat overlooked history as a treatment option for conformance and remedial casing repair. Recently, there has been greater interest in the use of sodium silicate-based technology for these applications. The environmentally friendly nature of sodium silicate has been a key reason for this renewed interest. Low cost, durability and advances in silicate chemistry are the other factors driving this resurgence. Sodium silicate is a unique chemical in that it can undergo different types of chemical reactions. This paper will review silicate chemistry and the different reactions for setting sodium silicate. The HS&E characteristics will also be discussed. Case histories will be presented in the application of sodium silicate for blocking gas migration along micro annuli behind casing, isolating near wellbore annular fluid crossflows via channels, and step processes used to gain control over casing "pin-hole-leaks." Also presented will be the setting reaction between sodium silicate and carbon dioxide and how it can be used for CO2 EOR profile control and interwell communication diversion.