Underground Monitoring to Support Refrigerated-Mined Rock Cavern Technology
Project Number
DE-FC26-02NT41296/FEW02-011302
Last Reviewed Dated
Goal
Provide demonstration-scale data to assess the potential for deployment and commercialization of a full-scale Refrigerated-Mined Rock Cavern Technology (RMRCT).
Performer(s)
CAES Development Company
Sandia National Laboratory (SNL)
Background
RMRCT is a technology that has been developed conceptually by DOE and its industry partner, PB-KBB, Inc., that involves storing natural gas in deep crystalline unfractured rock by chilling and compressing it to reduce the storage space required (Advanced Underground Gas Storage Concepts: Refrigerated-Mined Cavern Storage; Contract No. DE-AC26-97FT34349). A technical challenge associated with this process is the large-scale cyclic internal pressurization of a mined rock cavern in hard rock.
This project involves refining the RMRCT concept through analyses of the large-scale rockmass response in an actual compressed air energy storage facility (CAES) being built in Norton, Ohio. Measurements of pressure-induced deformations in the CAES facility will be conducted. The data gathered will be directly applicable to understanding the physical nature of the deformations which could occur at an RMRCT facility and thus reduce the risk, both technical and financial, of further development.
Accomplishments (most recent listed first)
A “Mutual Termination” action for this project was necessitated by changes in energy market conditions that have slowed the development of the compressed energy storage facility in Norton, Ohio, that was to be the focus of the agreed upon research. Original plans for the project envisioned geotechnical instrumentation installation and monitoring of the facility over a 2-year period. Changes in the energy market have resulted in slower than anticipated capital investment partnerships being established to fully develop this combined compressed energy storage/gas turbine electric generation facility. Initial estimates of delay in the project range from 2 to 5 years. As a result, the underground facility has being mothballed to lower maintenance expenses of the operation until the overall project is resumed.
Current Status
Sandia National Laboratory prepared a final report covering tasks in the Statement of Project Objectives that were completed at the time the mutual termination decision was made. These include: a review of the RMRCT facility concepts to assure that monitoring of the CAES facility meets the important engineering design and performance needs of a RMRCT facility; identification of performance requirements for measurement and instrumentation; selection of instrumentation locations to provide optimum opportunity to measure large-scale rockmass response to pressure cycling; and formalized instrumentation test plan to maximize collection of displacement, pressure, moisture, and temperature data in the mine.
