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        <name>YORKTOWN ENERGY PARTNERS IX, L.P.</name>
        <address>
          <com:street1>410 PARK AVENUE</com:street1>
          <com:street2>20TH FLOOR</com:street2>
          <com:city>NEW YORK</com:city>
          <com:stateOrCountry>NY</com:stateOrCountry>
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      <additionalInformation>Yorktown IX Company LP is the sole general partner of Yorktown Energy Partners IX, L.P. Yorktown IX Associates LLC is the sole general partner of Yorktown IX Company LP. As a result, Yorktown IX Associates LLC and Yorktown IX Company LP may be deemed to have the power to vote or direct the vote or to dispose or direct the disposition of the shares owned by Yorktown Energy Partners IX, L.P.</additionalInformation>
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      <name>Bryan H. Lawrence</name>
      <title>Managing Member of the General Partner's General Partner</title>
      <phone>(212) 515-2112</phone>
      <signature>/s/ Bryan H. Lawrence</signature>
      <city>NEW YORK</city>
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