Drilling fluids that include water-insoluble acid catalyst precursors or reaction products of such and uses for such drilling fluids

A sealed subterranean petroleum formation comprising:

• a subterranean wellbore positioned adjacent a subterranean petroleum formation;
• and
• a drilling fluid positioned in the subterranean wellbore, the drilling fluid comprising:
• a base fluid comprising an aqueous or non-aqueous solution;
• one or more formaldehyde-based resins, where the weight ratio of the one or more formaldehyde-based resins to the base fluid is from 1:100 to 50:100;
• one or more water-insoluble acid catalyst precursors or the reaction products of such water-insoluble acid catalyst precursors, where the weight ratio of the sum of the one or more water-insoluble acid catalyst precursors to the total drilling fluid is from 0.5:100 to 20:100.

A method for sealing a subterranean wellbore, the method comprising:

• introducing a drilling fluid into a subterranean wellbore, the subterranean wellbore positioned adjacent to a subterranean petroleum formation, where the drilling fluid comprises:
• a base fluid comprising an aqueous or non-aqueous solution;
• one or more formaldehyde-based resins, where the weight ratio of the one or more formaldehyde-based resins to the base fluid is from 1:100 to 50:100;
• introducing one or more water-insoluble acid catalyst precursors to the drilling fluid, where the water-insoluble acid catalyst precursor is converted to an acid catalyst in the drilling fluid in an amount operable to transition the drilling fluid from a liquid state to a gelled state.