Patent ID: 6823940
Filing Date: 2004-11-30
Classification: C09K,Y10S

Abstract:
A method of consolidating unconsolidated weak zones or formations containing unconsolidated rocks and minerals to prevent sloughing and forming a chemical casing comprising the steps of:(a) drilling the unconsolidated weak zones or formations with a drilling fluid having a pH in the range of from about 6 to about 10 and that comprises water, a polymeric cationic catalyst capable of accepting and donating protons which is adsorbed on the unconsolidated rocks and minerals, a particulate curable solid thermoset resin and a delayed acid catalyst for curing the solid resin, the drilling fluid forming a filter cake on the walls of the zone or formation that is cured by the delayed acid catalyst and consolidates the unconsolidated weak zones and formations so that sloughing is prevented; and (b) contacting the filter cake formed in step (a) with a treating fluid that comprises water, a water soluble or dispersible polymer which is capable of being cross-linked by a thermoset resin and causing the resin to be hard and tough when cured, and a water soluble or dispersible thermoset resin, the treating fluid components depositing on the filter cake formed in step (a) and the thermoset resin catalyzed by heat or the delayed acid catalyst, or both, curing into a hard and tough cross-linked chemical casing on the walls of the zone or formation.