<PAGE>


                                                                    EXHIBIT 31.2

                                 CERTIFICATIONS

I, Beverly A. Cummings, certify that:

1.   I have reviewed this annual report on Form 10-K of PrimeEnergy Corporation;

2.   Based on my knowledge, this annual report does not contain any untrue
     statement of a material fact or omit to state a material fact necessary to
     make the statements made, in light of the circumstances under which such
     statements were made, not misleading with respect to the period covered by
     this annual report;

3.   Based on my knowledge, the financial statements, and other financial
     information included in this report, fairly present in all material
     respects the financial condition, results of operations and cash flows of
     the registrant as of, and for, the periods presented in this annual report;

4.   The registrant's other certifying officer(s) and I are responsible for
     establishing and maintaining disclosure controls and procedures (as defined
     in Exchange Act Rules 13a-14 and 15d-14) for the registrant and have:

     a.   Designed such disclosure controls and procedures, to ensure that
          material information relating to the registrant, including its
          consolidated subsidiaries, is made known to us by others within those
          entities, particularly during the period in which this report is being
          prepared;

     b.   Evaluated the effectiveness of the registrant's disclosure controls
          and procedures as of a date within 90 days prior to the filling date
          of this annual report (the "Evaluation Date"); and

     c.   Presented in this annual report our conclusion about the effectiveness
          of the disclosure controls and procedures based on our evaluation as
          of the Evaluation Date;

5.   The registrant's other certifying officer(s) and I have disclosed, based on
     our most recent evaluation, to the registrant's auditors and the audit
     committee of the registrant's board of directors (or persons performing the
     equivalent functions):

     a.   All significant deficiencies in the design or operation of internal
          controls which could adversely affect the registrant's ability to
          record, process, summarize and report financial data and have
          identified for the registrant's auditors and material weaknesses in
          internal controls; and

     b.   Any fraud, whether or not material, that involves management or other
          employees who have a significant role in the registrant's internal
          controls; and

6.   The registrant's other certifying officers and I have indicated in this
     annual report whether there were significant changes in internal controls
     or in other factors that could significantly affect internal controls
     subsequent to the date of our most recent evaluation, including any
     corrective actions with regard to significant deficiencies and material
     weaknesses.


           March 30, 2004                     /s/ Beverly A. Cummings
                                              ----------------------------------
                                              Beverly A Cummings
                                              Chief Financial Officer
                                              PrimeEnergy Management Corporation
                                              Managing General Partner