All-Optical Multi-Sensor Well Monitoring System to Secure Gas Storage Operations
This project will introduce and work with California utilities to implement a safe gas storage reservoir monitoring program.
Paulsson, Inc.
Recipient
Van Nuys, CA
Recipient Location
20th
Senate District
46th
Assembly District
$1,345,004
Amount Spent
Completed
Project Status
Project Result
All technical work for this project has been completed. The project team selected and designed prototype sensors for the monitoring system and demonstrated the system at the PG&E McDonald Island Underground Gas Storage (UGS) facility. In October of 2021, the Enhanced Distributed Acoustic Sensor array with 2,500 sensors and Distributed Temperature Sensor with 1,800 sensors were successfully deployed. The project team has collected data over a period of three years with eight months of continuous data acquisition. The team is preparing the Final Report for publication.
The Issue
Underground energy storage is very important in balancing our energy supply infrastructure. The aging of downhole and surface equipment in underground gas storage fields, in combination with a lack of continuous monitoring of the downhole and surface equipment, have led to large failures that are slow to be detected and repaired, such as the Aliso Canyon gas leak in 2015. If the gas storage fields were monitored by robust sensors, the pre-failure symptoms could be recorded and problems could be mediated prior to failure.
Project Innovation
This project developed large aperture acoustic and temperature arrays of subsurface optical sensors that can detect anomalous flows, strains, temperatures, or fatigue-induced micro seismic events by continuously monitoring gas storage fields using an optical sensor system installed in wells along the entire production tubulars. These sensors will detect pre-failure micro seismic noise, excessive strain, and small leaks, allowing the operator to intervene before failures occur. The project designed and laboratory tested sensor prototypes, followed by deploying the field optical sensor system into a borehole at the PG&E McDonald Island gas storage facility. After the successful installation, Paulsson, Inc. performed a borehole monitoring survey for an intermittent period of three years with eight months of continuous monitoring using the installed optical acoustic and temperature sensors.
Project Goals
Project Benefits
This project developed fit-for-purpose optical sensors and sensor array combinations including distributed acoustic, temperature, and strain sensors. A comprehensive sensor system will enable continuous monitoring to safeguard underground gas storage wells and facilities for proactive risk mitigation. Avoiding failures will improve energy security and gas system safety. The system will also provide assurance against gas leakage and reduce environmental impacts of underground gas storage.
Environmental Sustainability
Gas leaked from underground gas storage facilities includes methane, which has a greenhouse gas effect 86 times that of CO2, and potentially air toxics such as benzene. The optical multi-sensor system developed, installed, and monitored under this CEC and PG&E sponsored project can detect and locate small leaks early anywhere along the vertical length of the gas storage wells. This data will notify the operators in time to prevent catastrophic events.
Safety
Gas underground storage wells are cycled frequently between injection and withdrawal periods. Therefore, this exposes the well to a faster aging process due to the cycling stress on the production tubing steel, the casing steel, and the concrete surrounding the casing. A monitoring system will improve safety of gas storage operation by providing the status of the gas field and equipment in real time and informing storage operators of potential issues.
Key Project Members
Bjorn Paulsson
Mike Wylie
Ruiqing He
David Xu
