MISSISSIPPI INTERIOR SALT BASIN
The MISB is the most productive basin in the northeastern Gulf Coast Region, having produced more than 1.5 billion barrels of oil and 8.0 Tcf of gas. Located on the north flank of the Gulf Coast Plain, with an average width of 125 miles and covering a total area of 6,000 square miles, it extends from northeastern Louisiana to southwest Alabama.
Southern Energy’s three main assets in the MISB are the Gwinville, Mechanicsburg, and Mount Olive East fields, which comprise over 89% of its Proved plus Probable reserves and approximately 88% of the present value of such reserves, with the remainder of the company’s assets comprising a number of lower value fields in the MISB.
Gwinville Field
Southern operates and owns a >95% working interest in approximately 20,400 held by production acres of land in the Gwinville field. The Gwinville property represents about 71% of the company’s Proved plus Probable (2P) reserves, and approximately 52% of Southern’s 2023 average production. The main producing zone is the Selma Chalk formation, with minor production from the City Bank formation. The Mississippi field office is located in the heart of the Gwinville field.
Mechanicsburg Field
Southern operates and owns a >98% working interest in approximately 3,400 held by production acres of land in the Mechanicsburg field. The Mechanicsburg property represents about 15% of the company’s Proved plus Probable (2P) reserves, and approximately 11% of Southern’s 2023 average production. The main producing zone is the Cotton Valley formation.
Mount Olive East Field
Southern operates and owns a >85% working interest in approximately 1,200 held by production acres of land in the Mount Olive East field. The Mount Olive East property represents about 4% of the company’s Proved plus Probable (2P) reserves, and approximately 19% of Southern’s 2023 average production. The main producing zone is the Eutaw formation.
Other MISB Fields
The Company owns and operates production from a number of other fields in the MISB within 40 miles of Gwinville, including Greens Creek and Williamsburg South gas fields, along with minor oil production from the Magee field.