Mr. Ian Atkinson reports

SOUTHERN ENERGY CORP. ANNOUNCES SUCCESSFUL COTTON VALLEY COMPLETION RESULTS AT WILLIAMSBURG

Southern Energy Corp. has released completion and initial flow-test results from the Terrible Creek 21-2 No. 2 Cotton Valley vertical well in the Williamsburg field. The well encountered a Cotton Valley C gross interval thickness of approximately 110 feet, which exceeded expectations based on the two previous offset deep wells that were drilled in the 1970s. The company perforated 71 feet of net pay in the Cotton Valley C interval and conducted a 72-hour flow test on the well without the need for a fracture stimulation. At the end of the flow test period, the well was flowing at a stabilized rate of 2.3 million cubic feet per day of natural gas plus 50 barrels of condensate per day (50 degrees API), equivalent to approximately 430 barrels of oil equivalent per day, on a 32/64ths-inch choke at a restricted flowing tubing pressure of 435 pounds per square inch gauge. The company is constructing the necessary well-site facilities and anticipates bringing the well on production by mid-November 2026.

Analogous Cotton Valley reservoirs at Seminary, Collins and Northeast Collins, which produce from similar depths, have exhibited oil phase behaviour, while the well's initial flow test results suggest a gas condensate reservoir. The condensate-rich production stream will increase Southern's liquid weighting while also benefiting from the strong deliverability and recovery characteristics commonly associated with gas condensate reservoirs. Southern is now conducting the necessary fluid phase testing to confirm these details and help plan future development.

Using 2-D seismic data, Southern has preliminarily mapped more than 7,200 acres of interpreted four-way closure at the Cotton Valley interval at Williamsburg. Assuming 160-acre spacing, this area could support more than 45 gross potential drilling locations. Based on preliminary estimates of expected development capital costs (material drilling efficiencies identified and no fracture stimulations required) and early estimates of Cotton Valley C initial rates and expected recoveries, at the company's current forecast liquids and natural gas pricing (including premiums), these future drilling locations are expected to provide high rates of capital return. Southern will monitor production performance after the well is brought on line and provide additional development and economic information when supported by sufficient performance data. The company currently has no Cotton Valley reserves booked in Williamsburg.

Ian Atkinson, president and chief executive officer of Southern, commented: "We are very excited with these initial test results from our first Cotton Valley liquids-rich well at Williamsburg. These results support further capital spending on the Cotton Valley C interval and allow Southern to advance planning for follow-up development. The Cotton Valley C interval was our primary target in this well and we have now established high-permeability deliverability with these results. We also encountered five highly prospective zones in the shallower Hosston and Sligo formations, which we will evaluate as part of our broader field development strategy. With the cash available on our balance sheet, Southern is positioned to assess a self-funded development program at Williamsburg with liquids production that would receive Louisiana light sweet crude pricing at a premium to West Texas Intermediate. The high-netback natural gas volumes will directly access Transco Zone 4 premium pricing with no third party transportation or processing costs as a result of our extensive company-owned infrastructure."

Southern has initiated the land and regulatory processes required to permit two potential follow-up Cotton Valley drilling locations. Subject to receipt of required approvals, final well planning and capital allocation, the company anticipates spudding the next well in early Q1 2027. The next well is expected to satisfy the company's remaining commitment under its joint venture wellbore participation agreement announced on May 26, 2026, being the second of the two commitment wells under that agreement.

New corporate presentation

A new corporate presentation highlighting Southern's recent operational progress and growth opportunities is now available on the company's website.

Qualified person statement

Gary McMurren, chief operating officer, who has over 25 years of relevant experience in the oil industry, has approved the technical information contained in this announcement. Mr. McMurren is registered as a professional engineer with the Association of Professional Engineers and Geoscientists of Alberta and received a bachelor of science in chemical engineering (with distinction) from the University of Alberta.

About Southern Energy Corp.

Southern Energy is a natural gas exploration and production company characterized by a stable, low-decline production base, a significant low-risk drilling inventory and strategic access to premium commodity pricing in North America. Southern has a primary focus on acquiring and developing conventional natural gas and light oil resources in the southeast Gulf states of Mississippi, Louisiana and eastern Texas. The company's management team has a long and successful history working together and has created shareholder value through accretive acquisitions, optimization of existing oil and natural gas fields and redevelopment strategies, including horizontal drilling and multistaged fracture completion techniques.

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