Salt Dome Storage for Petroleum Distillates
In the world of science and engineering, salt domes are more than just geological curiosities—they are efficient and economical strategic assets for energy storage. At United Lands Company, we recognize that these natural formations play a crucial role in securely storing essential resources. With global energy demands rising the use of salt domes in storage is a natural choice.
In this blog post, we’ll dive into the fascinating science behind salt dome storage, highlighting their importance in today’s energy landscape. They play a crucial role in the efficient movement of refinery feedstock and chemical production in Louisiana and anywhere these somewhat rare geologic formations are found.
What Are Salt Domes?
Formation Process
Salt domes are formed over millions of years by the upward movement of salt deposits buried deep beneath the Earth's surface. This process begins in ancient seas where salt accumulates as water evaporates. Over time, thick layers of sediment cover these deposits, and the buoyant nature of salt causes it to push upward, creating dome-like structures. On a human scale, these formations can be huge.
Structure and Features
Typically, salt domes can range from 1,000 to 10,000 feet in depth and several miles in diameter. One of their defining features is the impermeable cap rock that forms on top, making them mostly stable and an ideal formation within which to explore for oil & gas. This natural seal prevents leakage by providing stability to the formation. Within a large natural dome, caverns several thousand feet deep and a few hundred feet wide are hydro blasted downward into the salt. Each cavern can hold several hundred thousand barrels of distillate. The water used to form the cavern is pumped out and used as industrial brine. The remaining cavern’s side walls will not react with hydrocarbons and thus the salt crystal is an ideal natural and impermeable storage vessel for petroleum products.
Global Locations
Salt domes are found worldwide, with significant concentrations along the U.S. Gulf Coast, including Texas and Louisiana. Other notable locations include parts of Europe, Russia, the Middle East, and Africa. Their global presence underscores their potential for widespread use in energy storage solutions.
How Salt Domes Store Oil and Gas
Historical Use
The use of salt domes for storing oil and gas began in the 1940s. Initially utilized for the nation’s strategic petroleum reserves, these underground caverns have proven their worth by securely holding petroleum resources both economically and long term. The historical success of salt domes in this capacity proves their value.
Storage Process
Creating storage caverns in salt domes involves a technique called solution mining. We inject water into the salt deposit to dissolve the salt, creating a cavern. The resulting brine can be used in other industrial applications. Once the cavern is formed, oil, gas or other distillates are injected for storage. These resources can later be withdrawn as needed, providing reliable refinery feedstocks. A 4 – 6,000-foot string of pipe, reaching down to the bottom of the cavern, is used to pump nitrogen into the cavern, raising the distillates up for extraction. The process is reversed when storage is needed, the nitrogen being let out to increase the capacity of the cavern. Surface pipelines carry the distillates away to refineries for use as feedstock in chemical manufacturing or production of gasoline, etc.
Safety Features
Salt domes offer unparalleled safety for oil and gas storage due to their geological stability and impermeability. The natural cap rock and structure of the dome prevent leaks, contamination, and environmental damage. Hydrocarbons have no reaction with the crystals of salt forming the walls of the salt cavern. This makes salt caverns the preferred choice for secure and long-term storage.
The Environmental and Economic Benefits of Salt Dome Storage
Energy Security
Salt domes contribute to energy security by providing a stable and reliable storage solution for large volumes of oil and gas reserves. This ensures that energy supplies are maintained during disruptions, contributing to national and global energy stability. These large and naturally occurring storage facilities also smooth out the supply of the elements needed to manufacture the hundreds of products made with hydrocarbons.
Economic Impact
The economic benefits of salt dome storage are multifaceted. This includes job creation in the construction and maintenance of storage facilities, support for the energy industry all due to the economic efficiency of salt cavern storage.
Conclusion
By offering secure and efficient storage for oil & gas, these geological formations stand as a pillar in addressing today’s energy challenges. Their continued relevance underscores the need for innovation and investment in this sector. The efficient storage of these products has been going on for decades and the long-term leases in this sector let by United Lands are confirmation of the continued utility of salt cavern storage.