Water swellable cement sheath on demand, with sensing capability

A method of sealing propagating cracks in a sensor-laden cement sheath comprising the steps of:

• monitoring an electrical resistivity of the sensor-laden cement sheath to produce a measured value, wherein the sensor-laden cement sheath comprises a conductive sensor, an on-demand expanding agent, and a cement;
• activating a heat source when the measured value of the electrical resistivity is greater than an activation threshold, such that the measured value that is greater than the activation threshold is operable to indicate propagating cracks in the sensor-laden cement sheath;
• increasing a temperature of the sensor-laden cement sheath with the heat source to an activation temperature, wherein the activation temperature is operable to initiate a reaction between the on-demand expanding agent and water, wherein the activation temperature is greater than a formation temperature;
• reacting the on-demand expanding agent with water to produce a swelled agent, wherein the swelled agent occupies a greater volume than the on-demand expanding agent;
• and
• sealing the propagating cracks in the sensor-laden cement sheath with the swelled agent.