Determination of the optimum gauge length for borehole seismic surveys acquired using distributed vibration sensing

Abstract

Interest in the use of fibre-optic-based distibuted vibration sensing systems is rapidly expanding with users primarily drawn by its ability to make a large number of high-density strain measurements without the need for individual sensors. Unlike conventional measurements, strain is not measured at individual points but is instead measured across a section of the fibre (the gauge length). The gauge length (either an acquisition or processing parameter) is one of, if not the most, important parameters for DVS surveys having a direct influence on the resulting signal-to-noise-ratio and resolution. We have also derived a simple method for calculating its optimum value.