Detection of location of cement

A method for locating a cement composition in a wellbore, the method comprising:

• deploying a sensing system in the wellbore;
• deploying an acoustic emitter in the wellbore;
• wherein the acoustic emitter emits an acoustic signal at the resonance frequency of the hollow beads;
• introducing the cement composition into the wellbore;
• wherein the cement composition comprises:
• a cement, and
• hollow beads having a crush pressure and configured to emit an acoustic signal when imploded;
• pumping the cement composition through the wellbore to a depth with a wellbore pressure exceeding the crush pressure of the hollow beads to induce implosion of the hollow beads and the emission of the acoustic signal;
• sensing the emitted acoustic signal;
• and
• determining the location of the cement composition in the wellbore from the sensed emitted acoustic signal.

A system for locating a cement composition in a wellbore;

• the system comprising:
• the cement composition comprising:
• a cement, and
• hollow beads having a crush pressure and configured to emit an acoustic signal when imploded;
• a sensing system deployed in the wellbore;
• wherein the sensing system is configured to sense the emitted acoustic signal of the imploded hollow beads during the pumping of the cement composition;
• and
• an acoustic emitter deployed in the wellbore;
• wherein the acoustic emitter emits an acoustic signal at the resonance frequency of the hollow beads.