|
Frequently Asked Questions about the project
Why store natural gas underground?
The simple answer to “why store natural gas” is
to help balance demand with supply. Demand for natural gas
varies by day, week and month, and a large part of natural
gas demand is temperature-sensitive. “Why underground?” is
also simple – it is the safest and most economical
means for storing large volumes of natural gas, and for redelivering
it to the pipeline system when needed.
Natural gas in storage also serves as insurance against
unforeseen events such as pipeline service interruptions,
supply interruptions, natural disasters, extreme weather
conditions and other occurrences that may affect the production
supply, delivery of or demand for natural gas.
How is natural gas stored underground?
There are three main types of underground storage: depleted
oil and gas reservoirs, salt caverns and aquifers. Liberty
Gas Storage uses salt caverns. Salt caverns are attractive
for gas storage as they are essentially impermeable. They
also allow for high rates of gas injection and withdrawal
which help to balance daily demand with supply.
Salt caverns are constructed within
naturally-occurring geologic structures made up of salt.
The caverns are formed by injecting a fresh water stream
down a well bore and into the salt formation. As the salt
is leached away, forming the cavern, the produced brine is
removed and taken away to a licensed industrial or disposal
facility. Once the cavern is leached to its intended size,
the final brine is removed by injecting natural gas.
Salt caverns are also commonly used for liquid hydrocarbon
storage. For instance, the entire U.S. Strategic Petroleum
Reserve is stored in salt caverns. Currently, over 1,000
salt caverns store hydrocarbon reserves in the United States,
and the technology for creating, using, monitoring, metering
and maintaining salt caverns is well documented and proven.
How does the gas injection/withdrawal process work?
There are two methods by which gas is injected into underground
storage and both methods will be used depending on the pressure
of the gas in the pipeline compared to the gas in the cavern
at the time of the required injection. If the pressure in
the pipeline is higher than the pressure in the cavern, the
gas will free flow from the pipeline into the cavern without
any additional effort. This occurs when the gas inventory
in the cavern is at a low level. If the pressure in the pipeline
is lower than the pressure in the cavern, the gas pressure
will be increased by using gas compressors.
These two methods also are used in the withdrawal process
only in reverse. If the pressure in the cavern is higher
than the pipeline, the gas will free flow out of the cavern
into the pipeline. If the pressure in the cavern is less
than the pipeline pressure, the gas will be compressed using
gas compressors
Where does the gas go when it is removed from Liberty Gas Storage?
Liberty Gas Storage has pipeline interconnects with five
different interstate pipelines that can transport the gas
to markets in the Midwest, Northeast and Southeastern United
States.
Why was this location chosen for Liberty Gas Storage?
The site selection for Liberty Gas Storage was primarily based
on two factors. The first is the location and quality of
the salt dome. The second factor is size and location of
pipeline networks relative to the salt dome. The more pipelines
that can be accessed, the better the site is to develop.
How safe is underground natural storage?
The natural gas industry has successfully stored natural
gas in facilities for nearly 90 years. Sempra Energy (majority
owner of Liberty Gas Storage) has safely and efficiently
built and operated similar gas storage facilities in California
and Michigan. Sempra Energy and its affiliate companies
take pride in an excellent environmental and safety record
and ensure continued dedication to performing at the highest
safety levels.
There are now 23 salt cavern natural gas storage projects
in the United States, with 20 along the Gulf Coast that have
a solid safety record. The Liberty Gas Storage facility uses
the newest technologies and has engineered and built the
facility to regulatory and modern industry-safety standards.
Can hurricanes or floods damage or destroy Liberty Gas Storage?
Hurricanes and floods can damage the surface facilities
but not the salt cavern. Since the cavern is underground
it is not subject to the forces associated with the wind
or water. To mitigate the risk of surface damage, the surface
facilities have all been constructed to withstand wind
speeds in excess of 100 mph, which exceeds local building
codes. The compressors themselves were built above ground
level to protect them from water damage in the event of
a flood.
The facility also has the ability to produce its own
electrical power in the event commercial power is lost
when power lines are damaged during hurricanes. The reduced
risk of service curtailment during these type storms is
recognized by the gas industry and is one reason underground
storage fields are beneficial and sought after by the gas
industry.
Who regulates underground natural gas storage?
Liberty Gas Storage operates under the oversight of numerous
regulatory agencies, including the Federal Energy Regulatory
Commission, the Department of Energy, the Department of
Transportation Office of Pipeline Safety, the U.S. Army
Corps of Engineers, the U.S. Fish and Wildlife Service,
the Louisiana Department of Wildlife and Fisheries, the
Louisiana Department of Natural Resources, the Louisiana
Department of Environmental Quality and the Occupational
Safety and Health Administration.
What is the environmental impact of Liberty Gas Storage?
Liberty Gas Storage believes in treating the Earth's resources
with respect. We are committed to protecting and conserving
the environment and to the health and safety of our employees,
our customers and the communities in which we operate and
provide service.
To that end, Liberty Gas Storage built this project in compliance
with all applicable environmental laws, regulations and permit
requirements, and in a manner that minimizes impacts to landowners
and the environment.
How many people will Liberty Gas Storage employ?
During construction of the project, contractors to Liberty
Gas Storage employed hundreds of people skilled in operating
construction equipment, welding and general labor. Liberty
employs approximately 10 people locally on a full time
basis.
How can I get more information on Liberty Gas Storage?
You can check out the rest of this Web site for more information,
or for specific project information contact Carlos Mauer.
For media inquiries contact Art Larson. |
