Flow-Induced Noise in Fiber-Optic 3C Seismic Sensors for Permanent Tubing-Conveyed Installations

This paper report the test results acquired of flow induced noise in a fiber-optic 3-C seismic station, where the tests represents some of the possible conditions that may be expected in flowing wells. The tests were performed to evaluate a fiber-optic sensor tool for tubing-conveyed installations in a controlled-flow test facility. The results of these tests demonstrated that the active-coupled 3-C fiber-optic seismic station installed on production tubing inside cemented well casing was capable of detecting very small seismic signals at high single-phase flow rates for frequencies in the 10-600 Hz band. Test results also demonstrated that the active 3-C station has a very efficient decoupling from flow-induced noise (compared to a passive 3-C seismic station directly attached to the production tubing), while at the same time having good coupling to the casing and formation. Test results showed that two-phase flow increased the noise at high frequencies over that of single-phase flow; however, for frequencies <100 Hz the noise increase is small. This testing indicates the potential to acquire high-resolution, multi-component seismic data in flowing wells under certain conditions with fiber-optic sensors.