13D Filing: Corvex Capital and Energen Corporation (EGN)

The percentage calculated in the immediately foregoing paragraph is calculated based on a total of 97,201,944
Shares outstanding as of October 31, 2017, as reported in the Issuers Quarterly Report on Form 10-Q filed with the SEC on November 8, 2017.

The call options referenced above and in Item 4 are over-the-counter market
American-style call options referencing an aggregate of 1,456,048 Shares, which have an exercise price of $40 per Share and expire on January 31, 2019. Such options were acquired for a premium of $17.58 per option.

In addition, as referenced in Item 4, Corvex sold over-the-counter market
European-style put options referencing an aggregate of 1,456,048 Shares, which have an exercise price of $40 per Share and expire on January 31, 2019 or the date on which the corresponding American-style call option described above in this Item
5 is exercised. Such options were sold for a premium of $0.01 per option.

Also, as previously disclosed, Corvex has sold listed American-style put
options referencing an aggregate of 415,200 Shares with an exercise price of $40 per Share, which expire on January 19, 2018.

(c) Except as set
forth in this Schedule 13D, there have been no transactions in the Shares during the sixty days prior to the date hereof by any of the Reporting Persons.

(d) The limited partners of (or investors in) each of the private investment funds for which Corvex or its affiliates acts as general partner and/or
investment adviser have the right to participate in the receipt of dividends from, or proceeds from the sale of, the Shares held for the accounts of their respective funds in accordance with their respective limited partnership interests (or
investment percentages) in their respective funds.

(e) Not applicable.