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                                                                  EXHIBIT 10.151


                     VOTING AGREEMENT AND IRREVOCABLE PROXY
                     --------------------------------------

                  This Voting Agreement and Irrevocable Proxy (this "AGREEMENT")
dated as of November ___, 2005 is executed by and among Delta Petroleum
Corporation, a Delaware corporation ("HOLDINGS"), Delta Petroleum Corporation, a
Colorado corporation ("DP COLORADO"), DPCA LLC, a Delaware limited liability
company and wholly-owned subsidiary of DP Colorado ("ACQUISITION"), and the
undersigned stockholders of Castle Energy Corporation (referred to herein
individually as a "STOCKHOLDER" and collectively as the "STOCKHOLDERS").

                  WHEREAS, Holdings, DP Colorado, Acquisition, and Castle Energy
Corporation, a Delaware corporation (the "COMPANY") have executed that certain
Agreement and Plan of Merger dated as of November 8, 2005 (the "MERGER
AGREEMENT") whereby Company will be merged with and into Acquisition, and
Acquisition will be the surviving company (the "MERGER"); and

                  WHEREAS, as a condition to its willingness to enter into the
Merger Agreement, Holdings, DP Colorado and Acquisition have required that each
of the undersigned Stockholders enter into and each of the Stockholders has
agreed to enter into this Agreement; and

                  WHEREAS, Holdings, DP Colorado and Acquisition are relying on
this Agreement and the irrevocable proxies in incurring expense in reviewing
Company's business, in preparing the Merger Agreement and in undertaking other
actions necessary for the consummation of the Merger.

                  NOW THEREFORE, the parties hereto agree as follows:

         1. Each Stockholder hereby represents and warrants to Holdings, DP
Colorado and Acquisition that such Stockholder (a) is the registered and
beneficial owner of and has the exclusive right to vote the shares of capital
stock of Company set forth below his, her or its name on the signature page
hereto ("SHARES"), and (b) has not entered into and is not a party of any voting
agreement or voting trust with respect to the Shares.

         2. Each Stockholder agrees that, from and after the date hereof and
until the date on which this Agreement is terminated pursuant to Section 6
hereof, at any Company stockholders meeting, or any adjournment thereof (a
"MEETING"), such Stockholder shall: (a) appear at each such meeting or otherwise
cause the Shares to be counted as present thereat for purposes of calculating a
quorum; and (b) vote (or cause to be voted), in person or by proxy, or deliver a
written consent (or cause a consent to be delivered) covering, all the Shares,
and any other voting securities of the Company (whenever acquired), that are
beneficially owned by such Stockholder or as to which such Stockholder has,
directly or indirectly, the right to vote or direct the voting, in favor of
approval of the Merger Agreement and the Merger.

         3. Each Stockholder hereby revokes any previously executed proxies and
hereby constitutes and appoints Roger Parker and Kevin Nanke (the "PROXY
HOLDER"), each of them individually, with full power of substitution, as his,
her or its true and lawful proxy and attorney-in-fact to vote at any Meeting all
of such Stockholder's Shares in favor of the authorization and approval of the
Merger Agreement, the Merger and the other agreements and transactions
contemplated thereby, with such modifications to the Merger Agreement and the
other agreements and transactions contemplated thereby as the parties thereto
may make.

         4. Each Stockholder hereby covenants and agrees that, except as set
forth on Schedule 1 hereto, until this Agreement is terminated in accordance
with its terms, each Stockholder will not, and will not agree to, without the
consent of DP Colorado: (a) directly or indirectly, sell, transfer, assign,
pledge, hypothecate, cause to be redeemed, or otherwise dispose of any of the
Shares; (b) grant any proxy or interest in or with respect to any such Shares;
(c) deposit such shares into a voting trust; or (d) enter into another voting
agreement or arrangement with respect to such Shares except as contemplated by
this Agreement, unless the Stockholder causes the transferee of such Shares to
deliver to DP Colorado an amendment to this Agreement whereby such transferee or
other holder becomes bound by the terms of this Agreement.






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         5. The Stockholders acknowledge that Holdings, DP Colorado and
Acquisition are relying on this Agreement in incurring expense in reviewing
Company's business, in preparing for the Merger and in undertaking other actions
necessary for the consummation of the transactions contemplated in the Merger
Agreement and that the proxy granted hereby is coupled with an interest and is
irrevocable to the full extent permitted by applicable law, including Section
212 of the Delaware General Corporation Law. The Stockholders acknowledge that
the performance of this Agreement is intended to benefit Holdings, DP Colorado
and Acquisition.

         6. The voting agreement and irrevocable proxy granted pursuant hereto
shall continue in effect until the earlier to occur of (a) the termination of
the Merger Agreement, as it may be amended or extended from time to time, or (b)
the consummation of the Merger.

         7. This Agreement may not be modified, amended, altered or supplemented
in any respect except upon the execution and delivery of a written agreement
executed by Holdings, DP Colorado, Acquisition, and the Stockholders.

         8. This Agreement may be executed simultaneously in two or more
counterparts, each of which shall be deemed an original but all of which shall
constitute one and the same instrument.

         9. This Agreement, together with the Merger Agreement and the
agreements contemplated thereby, embody the entire agreement and understanding
of the parties hereto in respect to the subject matter contained herein. This
Agreement supersedes all prior agreements and understandings among the parties
with respect to the subject matter contained herein.

         10. All notices, requests, demands, and other communications required
or permitted hereby shall be in writing and shall be deemed to have been duly
given if delivered by hand or by certified or registered mail (return receipt
requested) with postage prepaid to the addresses of the parties hereto set forth
on below their signature on the signature pages hereof or to such other address
as any party may have furnished to the others in writing in accordance herewith.

         11. The parties agree that irreparable damage would occur in the event
that any of the provisions of this Agreement were not performed in accordance
with their specific terms. It is accordingly agreed that the parties shall be
entitled to specific performance of the terms hereof, this being in addition to
any other remedy to which they are entitled at law or in equity. Each of the
parties further agrees to waive any requirements for the securing or posting of
any bond in connection with obtaining any such equitable relief.

         12. This Agreement and the relations among the parties hereto arising
from this Agreement shall be governed by and construed in accordance with the
laws of the State of Delaware.

                            [SIGNATURE PAGES FOLLOW]

















                                       -2-
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                  IN WITNESS WHEREOF, the parties have executed this Agreement
as of the date above written.


                              /S/ ROGER A. PARKER
                              --------------------------------------------------
                              Delta Petroleum Corporation


                              /S/ ROGER A. PARKER
                              --------------------------------------------------
                              Delta Petroleum Corporation


                              /S/ ROGER A. PARKER
                              --------------------------------------------------
                              DPCA LLC, by its Sole Member


                              /S/ SALLY W. CASTLE
                              --------------------------------------------------
                              Estate of Joseph L. Castle II, by Sally W. Castle,
                               Executor
                              1,434,699 Shares

                              /S/ SALLY W. CASTLE
                              --------------------------------------------------
                              Sally W. Castle
                              55,925 Shares

                              /S/ RICHARD E. STAEDTLER
                              --------------------------------------------------
                              Richard E. Staedlter
                              74,600 Shares

                              /S/ MARTIN R. HOFFMANN
                              --------------------------------------------------
                              Martin R. Hoffman
                              36,000 Shares

                              RUSSELL S. LEWIS
                              --------------------------------------------------
                              Russell S. Lewis
                              62,000 Shares

                              JOHN P. KELLER
                              --------------------------------------------------
                              John P. Keller
                              111,000 Shares

                              SIDNEY F. WENTZ
                              --------------------------------------------------
                              Sidney F. Wentz
                              78,000 Shares

                              JOSEPH L. CASTLE III
                              --------------------------------------------------
                              Joseph L. Castle III
                              218,784 Shares

                              /S/ KATHRYN VAN BLARCOM
                              --------------------------------------------------
                              Kathryn Van Blarcom
                              61,385 Shares

                              /S/ SALLIE B. HARDER
                              --------------------------------------------------
                              Sallie B. Harder
                              189,885 Shares





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                                   Schedule 1

Estate of Joseph L. Castle II may sell up to 150,000 Shares

Kathryn Van Blarcom, Sallie B. Harder and Joseph L. Castle III may each sell up
to 33,333 Shares, subject to the right to reapportion such number among
themselves as they shall determine