Acoustic Geolocation of Microsystems in Downhole Environments

Autonomous microsystems are important for downhole monitoring to enhance the safety and efficiency of oil and gas production. We propose and computationally validate a previously unreported method for localizing autonomous microsystems in downhole environments, based on the time difference of arrival of low-frequency acoustic signals. This method eliminates the need for clock synchronization between the downhole microsystem and surface acoustic sources, and removes the requirement for specialized acoustic components by leveraging existing pressure sensors to detect low-frequency acoustic signals. This work shows that below <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$80 \text{Hz}, 60 \mathrm{m}$</tex> localization resolution can be achieved at 1.8 km depth.