CUSIP No. 269279402

The following constitutes Amendment No. 2 (“ Amendment No. 2 ”) to the Schedule 13D filed by the undersigned with the Securities and Exchange Commission on December 23, 2015, as amended by Amendment No. 1 filed on June 15, 2017 (as so amended, the “ Schedule 13D ”). This Amendment No. 2 amends the Schedule 13D to disclose the issuance to ESAS of the ESAS June 20, 2017 PIK Shares (as defined in Item 5 below).

Capitalized terms used in this Amendment and not otherwise defined herein have the respective meanings given in the Schedule 13D. Unless set forth below, all previous Items set forth in the Schedule 13D remain unchanged.

Item 2 is hereby amended and restated to read as follows:

(a) This statement on Schedule 13D is filed jointly by the following entities and persons, all of whom are together referred to herein as the “ Reporting Persons ”:

(b) The address of the principal business address of each of the Reporting Persons is 200 Crescent Court, Suite 1900, Dallas, Texas 75201.

(c) The principal business of ESAS is investing in energy companies and energy assets. The principal business of Main Fund is investing in energy companies and energy assets and acting as a managing member of ESAS. The principal business of Bluescape GP is acting as the general partner of Main Fund and other funds that Bluescape GP controls. The principal business of Bluescape GP Holdings is acting as the manager of Bluescape GP and other funds that Bluescape GP Holdings controls. The principal business of Charles John Wilder, Jr. is acting as the manager of Bluescape GP Holdings and its affiliates and as the manager or member of other investment and operating entities.

(d) No Reporting Person has, during the last five years, been convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors).

(e) No Reporting Person has, during the last five years, been a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding was or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws.

(f) Each of ESAS, Main Fund, Bluescape GP and Bluescape GP Holdings is organized under the laws of the State of Delaware. Charles John Wilder, Jr. is a citizen of the United States of America.

Item 3 is amended by appending the following text:

Since June 15, 2017, the filing date of Amendment No. 1 to the Schedule 13D, acquisitions of beneficial ownership of Shares were consummated with the use of the following funds:

ESAS holds $47.9 million in aggregate principal amount of the 1.75 Lien Term Loans and, on June 20, 2017, received 192,609 Shares as an interest payment under the 1.75 Lien Term Loan Credit Agreement.

Item 5 is hereby amended and restated to read as follows:

On June 12, 2017, the Issuer effectuated a 1-for-15 reverse share split of its common stock (the “Reverse Stock Split”) pursuant to which every 15 Shares issued and outstanding prior to the Reverse Stock Split were converted into one Share, with fractional Shares being rounded up to the next whole Share. The numbers of Shares reported in this Amendment are adjusted to give effect to the Reverse Stock Split.

On June 20, 2017, the Issuer elected to pay interest on its 1.75 Lien Term Loans by issuing a total of 2,745,754 Shares (the “ June 20, 2017 PIK Shares ”), 192,609 of which were issued to ESAS (the “ ESAS June 20, 2017 PIK Shares ”) with respect to the $47.9 million aggregate principal amount of the 1.75 Lien Term Loans it holds. The Issuer’s election to pay interest by issuing the June 20, 2017 PIK Shares is reported in the Issuer’s Current Report on Form 8-K filed with the Securities and Exchange Commission on June 22, 2017.

(a) The aggregate percentage of Common Stock reported owned by each person named herein is based upon 26,657,825 Shares comprised of (i) the 5,017,922 Shares underlying the Financing Warrants, (ii) the 18,894,149 Shares outstanding as of May 5, 2017, as reported in the Issuer’s Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on May 10, 2017 and (iii) the 2,745,754 June 20, 2017 PIK Shares.

(a) As of the date hereof, ESAS beneficially owned 6,433,630 Shares (consisting of (i) 1,415,708 Shares and (ii) 5,017,922 Shares underlying the Financing Warrants referenced below) constituting collectively approximately 24.1% of the outstanding Shares.

(a) As of the date hereof, Main Fund may be deemed the beneficial owner of the 6,433,630 Shares beneficially owned by ESAS (consisting of (i) 1,415,708 Shares and (ii) 5,017,922 Shares underlying the Financing Warrants referenced below), constituting collectively approximately 24.1% of the outstanding Shares.

(a) As of the date hereof, Bluescape GP may be deemed the beneficial owner of the 6,433,630 Shares beneficially owned by ESAS (consisting of (i) 1,415,708 Shares and (ii) 5,017,922 Shares underlying the Financing Warrants referenced below), constituting collectively approximately 24.1% of the outstanding Shares.

(a) As of the date hereof, Bluescape GP Holdings may be deemed the beneficial owner of the 6,433,630 Shares beneficially owned by ESAS (consisting of (i) 1,415,708 Shares and (ii) 5,017,922 Shares underlying the Financing Warrants referenced below), constituting collectively approximately 24.1% of the outstanding Shares.

(a) As of the date hereof, Charles John Wilder, Jr. beneficially owned 18,125 Shares and may be deemed the beneficial owner of the 6,433,630 Shares beneficially owned by ESAS (consisting of (i) 1,415,708 Shares and (ii) 5,017,922 Shares underlying the Financing Warrants referenced below), constituting collectively approximately 24.2% of the outstanding Shares.

(c) The Reporting Persons have effected the following transactions involving securities of the Issuer during the past 60 days:

(i) As described in Item 6, ESAS received the Financing Warrants in connection with its purchase of $70,000,000 principal amount of the 1.5 Lien Notes.

(ii) As described in this Item 5, ESAS received the ESAS June 20, 2017 PIK Shares in connection with the Issuer’s election to effect the payment of interest on the 1.75 Lien Term Loans through the issuance of the June 20, 2017 PIK Shares.

(d) No person other than the Reporting Persons has the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the shares of Common Stock beneficially owned by any Reporting Persons.

The foregoing discussion is also qualified in its entirety by reference to the form of Financing Warrant, Registration Rights Agreement and the 1.75 Lien Term Loan Credit Agreement, copies of which are filed as Exhibits 10.6, 10.12 and 10.14, respectively, to the Current Report on Form 8-K filed by the Issuer on March 15, 2017 and are incorporated by reference herein.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.