PR244-231111-R01 Implementing Fiber Optic Technology for Underground Gas Storage Well Monitoring

Conventional well integrity inspection requires frequent well entry, which not only introduces additional well integrity risks due to the invasive nature of the workover activities but also adds significant cost to the inspection process. Taking active underground gas storage (UGS) wells out of service for direct inspection can also strain natural gas deliverability and the ability of the storage system to meet the market demand. Distributed fiber optic sensing (DFOS) technology offers the benefit of continuous measurement along the entire length of the fiber optic cable without frequent well entry and may potentially reduce the cost in well integrity management.

This report describes a comprehensive research program that investigated various DFOS technologies through a literature review, a review of past research programs, and full-scale laboratory tests. A comprehensive understanding of the capabilities and limitations of various DFOS technologies for UGS well monitoring applications was established. This should assist UGS operators in developing a reliable solution for using DFOS technology as an alternative well integrity monitoring method that allows the intervals for mechanical integrity tests or traditional well inspections, as specified by regulators, to be extended.

This document aims to provide technical references to assist UGS operators improve their ability to make informed decisions regarding incorporating DFOS technologies into UGS well integrity monitoring.