A three-component optical sensor for borehole seismic applications

Abstract

We describe a new optical three-component accelerometer for borehole applications. Field data acquired in early 2020 in a fiber-optic-instrumented well in Houston, Texas, show that the new optical accelerometer is a viable borehole seismic sensor, measuring signals at frequencies from subhertz to hundreds of hertz. It is argued that an array of these sensors could be used to complement distributed acoustic sensing (DAS) technology to compensate for the inability of DAS sensors to measure wavefield polarization. This hybrid fiber-optic receiver array would be a fully optical wide-bandwidth sensor array without any electronics in the well. With a maximum operational temperature expected to exceed 200°C, this array would not be affected significantly by possible high temperatures in the near-reservoir section of the well.