Marathon Pipe Line LLC operates or provides oversight for Marathon Petroleum Company’s 11 active storage caverns at three separate cavern facilities. Underground storage in caverns provide a safe, economical method to store large volumes of hydrocarbons. Caverns are pressure containing, and can cost significantly less than similar volume surface pressure vessels. MPC uses caverns to store both propane and butane to support refineries.
The roofs of the Woodhaven caverns are 1,000 feet below grade. There are eight caverns at the facility: butane is stored in five caverns and propane is stored in the remaining three. Excess butane is stored during the summer season, and is then sent back to the refineries during the winter for blending. Propane is sold to customers over a loading rack. Brine is stored in two up-ground reservoirs.
Catlettsburg has two storage caverns, located 500 feet below grade. One cavern stores propane. The second cavern was finished in 2012 and is the first shale cavern to be built in the U.S. in 25 years. This cavern improves the safety of butane handling, enhances supply reliability, and reduces storage and transportation costs for excess summer butanes.
The Canton storage cavern is located within the Canton Refinery and stores excess butane. This is the deepest MPL cavern with the roof being 3,400 feet below grade. Brine is stored in an up-ground reservoir approximately one mile from the cavern wellhead.