US Patent 11187057 Compositions and methods for well completions

Expansive cements for use in cementing subterranean wells comprise water, an inorganic cement and one or more particulate materials that swell upon contact with a water immiscible fluid. The cements may further comprise a water immiscible fluid. Such cements are designed to seal microannuli arising from the presence of water immiscible fluids on casing surfaces, borehole wall surfaces or both.