As part of SoCalGas’ risk assessment of the Aliso Canyon natural gas storage facility, the Division of Oil, Gas, and Geothermal Resources (DOGGR) required SoCalGas to assess the potential geologic, seismologic, and geomechanical hazards at Aliso Canyon, including landslides, ground shaking, and fault displacement. SoCalGas assembled a team of renowned experts in various scientific and engineering fields to conduct the geologic, seismologic, and geomechanical studies. Their work plans were reviewed and approved by DOGGR and independent experts from the National Labs. Draft reports of the studies were made available to DOGGR and the National Labs on March 20, 2019. The work completed by the expert team has involved extensive scientific and engineering analyses of the wells at the facility and the facility’s geology, including cutting-edge approaches to assessing potential geologic, seismologic, and geomechanical risks.
Overall, the studies found the seismic risks at Aliso Canyon are relatively low, and indicate these risks can be reasonably managed and/or mitigated over the life of the facility.
The Importance of Aliso Canyon
Aliso Canyon serves more than 11 million customers and provides fuel to 17 natural gas-fired power plants. It is a critical part of the region’s energy infrastructure – more than 90 percent of Southern Californians depend on gas for heat and hot water, and approximately 60 percent of all the electricity generated in California is made by natural gas-fired power plants. Natural gas storage is especially important for electric generation because it supports renewable power sources, like wind and solar, and allows us to avoid burning dirty fuels, like diesel or coal, to keep the lights on. When the wind doesn’t blow or the sun doesn’t shine for renewable electric generators, the natural gas from Aliso Canyon helps to fill those energy gaps.
Aliso Canyon is centrally located in the Santa Susana Mountains, allowing for a quick and effective response to local, real-time energy demands. The location of the field is important because, unlike electricity, natural gas typically travels at relatively slow speeds in the range of 20-30 miles per hour. For example, it could take approximately ten hours for natural gas supplies to travel through SoCalGas’ transmission system from Blythe to several power plants located in the Los Angeles basin. By contrast, natural gas withdrawn from Aliso Canyon can meet demand significantly quicker, within one to two hours. Natural gas storage allows both large and small customers to enjoy a consistent supply of natural gas to heat their homes, to cook their food, and to power their businesses, twenty-four hours a day, seven days a week.
Our Commitment to Safety
In support of continued safety, Aliso Canyon is being held to the most rigorous monitoring, inspection and safety requirements in the nation. Ongoing steps to maintain accountability include:
- Testing or abandonment of wells that remain temporarily plugged;
- Real-time pressure monitoring of all wells;
- Visual inspections of each well four times a day;
- Daily infrared thermal imaging scanning of each well to detect leaks;
- Operation of the fence line methane monitoring system; and
- Community engagement through the Community Advisory Council.
Well Inspection Update
We continue to work with DOGGR and CPUC to complete a comprehensive safety review of all wells at Aliso Canyon. On the first and third Friday of every month, SoCalGas provides DOGGR with an updated well inspection report.
As of Friday, Jan. 18, 2019:
- 114 (or 100 percent) of the active wells at Aliso Canyon have completed the first phase of required tests;
- 64 wells have completed all required tests, and of those 62 wells have received final DOGGR approval;
- 10 wells are currently in the second phase of inspections;
- 36 wells are in the process of abandonment; and
- 4 well has been plugged and abandoned.
Well inspection test results are posted on DOGGR’s website and can be found here.
More on Infrastructure, Technology, and Safety Enhancements
SoCalGas has worked diligently to complete what experts have called “the most comprehensive safety review in the country.” creating multiple layers of safety at Aliso Canyon. Work we have completed includes:
- Replacing the inner steel tubing of every approved well;
- Using the casing around the new inner steel tubing — tested to ensure integrity under pressure — to provide a physical, secondary barrier of protection against potential leaks;
- Operating the facility at reduced pressure, as directed by CPUC;
- Withdrawing and injecting natural gas only through the inner steel tubing of those wells that have passed all tests and have been approved for use by DOGGR.
We have also introduced a suite of advanced leak-detection technologies and practices that allow for early detection of leaks and help quickly identify anomalies, such as changes in well pressure. These enhancements include:
- An infrared fence-line methane detection system with eight pairs of infrared methane monitors;
- Around-the-clock monitoring of the pressure in all wells from our 24-hour operations center;
- Twice-daily patrols to visually examine every well;
- Daily scanning of each well using sensitive infrared thermal imaging cameras that can detect leaks;
- Enhanced training for our employees and contractors.
- A summary of the changes at each well at Aliso Canyon is available as a PDF.
Community Engagement and Communication
SoCalGas has also implemented a Natural Gas Storage Facility Community Notification system for members of the community to sign up to receive notifications via phone call, text message and/or email, in the event of a release of natural gas at any one of SoCalGas’ four natural gas storage facilities.