Mr. Drew Mair reports

ENERPLUS ANNOUNCES 2023 YEAR END RESERVES RESULTS

Enerplus Corp. has released its year-end 2023 reserves under Canadian National Instrument 51-101 standards and U.S. standards. All amounts in this news release are stated in U.S. dollars unless otherwise specified.

Year-end 2023 reserves summary

Canadian NI 51-101 standards before deduction of royalties (gross) and forecast prices in U.S. dollars:

• Gross proven plus probable reserves were 585.1 million barrels of oil equivalent, a decrease of 3 per cent year over year, with reserves additions largely offsetting production, technical revisions, economic factors and dispositions.
• Gross 2P reserves in North Dakota were 422.9 MMboe, approximately flat to year-end 2022.
• Enerplus added 33.0 MMboe of gross 2P reserves from North Dakota in 2023 (including technical revisions and economic factors), replacing 100 per cent of 2023 North Dakota production.
• In North Dakota, gross 2P finding and development costs were $20.67 per boe, including future development costs.

U.S. standards after deduction of royalties (net) and constant prices in U.S. dollars:

• Net total proven reserves were 281.8 MMboe, a decrease of 13 per cent year over year, primarily due to Marcellus volume revisions, as a result of the approximately 60-per-cent-lower constant natural gas price assumption used for the year-end 2023 reserves.
• Net proven reserves in North Dakota decreased 2 per cent compared with year-end 2022.
• Enerplus added 24.4 MMboe of net proven reserves from North Dakota in 2023 (including technical revisions and economic factors), replacing 92 per cent of 2023 North Dakota production.
• In North Dakota, net proven F&D costs were $26.08 per boe, including FDC.

"Enerplus's high-quality inventory life in North Dakota continues to support a sustainable long-term outlook for our business," said Ian C. Dundas, president and chief executive officer. "Our track record of consistent operational execution continues to deliver reserves additions at competitive costs."

Year-end reserves evaluations

Reserves summary

The information herein sets out Enerplus's gross and net (prepared in accordance with Canadian National Instrument 51-101 standards) and net (prepared in accordance with U.S. standards) crude oil, natural gas liquids and natural gas reserves volumes as at Dec. 31, 2023. Under different price scenarios, these reserves could vary as a change in price can affect the economic limit associated with a property. For additional information regarding Enerplus's crude oil, NGLs and natural gas reserves as at Dec. 31, 2023, see Enerplus's annual information form for the year ended Dec. 31, 2023, on Enerplus's SEDAR+ profile, and Enerplus's U.S. Form 40-F for the year ended Dec. 31, 2023, on EDGAR, each of which is anticipated to be filed on Feb. 22, 2024.

Future development costs

Changes in forecast FDC occur annually as a result of development activities, acquisition and divestment activities, and capital cost estimates that reflect the evaluators' best estimate of the capital required to bring the proven and proven plus probable reserves on production. The aggregate of the exploration and development costs incurred in the most recent year and the change during the year in estimated FDC generally reflect the total finding and development costs related to reserves additions for that year.

A summary of the estimated FDC required to bring the total proven and proven plus probable reserves on production is set out herein.

Electronic copies of the AIF and Form 40-F, along with Enerplus's 2023 management's discussion and analysis and financial statements, and other public information, including investor presentations, are available on the company's website. For further information, please contact investor relations at 1-800-319-6462 or e-mail investorrelations@enerplus.com.

About Enerplus Corp.

Enerplus is an independent North American oil and gas exploration and production company focused on creating long-term value for its shareholders through a disciplined, returns-based capital allocation strategy and a commitment to safe, responsible operations.

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