Method of encapsulating signaling agents for use downhole

A method of wellbore operations comprising:

• combining first and second solutions that each comprise a reactive monomer and a fluid that is immiscible with a fluid in the other solution, and at least one of the first or second solutions having a signaling agent;
• forming an emulsion with the first and second solutions that comprises a continuous phase, and amounts of a dispersed phase containing the signaling agent and distributed within the continuous phase;
• forming polymeric layers around the amounts of the dispersed phase by reacting monomers that define capsules containing the signaling agent;
• adjusting a concentration of a one of the reactive monomers to adjust a characteristic of polymer layers;
• disposing the capsules in, cement that lines a wellbore;
• and
• evaluating a condition of the cement by sensing signaling agent that has escaped from the capsules in the cement.

A method of wellbore operations comprising:

• using an interfacial polymerization technique that comprises combining a monomer with a cross-linking monomer to form capsules that comprise a signaling agent disposed within a polymer layer;
• adjusting an amount of the cross-linking monomer to control a characteristic of the polymer layer;
• disposing the capsules in a wellbore;
• and
• assessing a characteristic of the wellbore based on sensing the signaling agent escaping the capsules.