Exhibit 10.7

                                 [WOODSIDE LOGO]

                           Woodside Energy (USA) Inc.


September 7, 2005


Mr. Martin V. Black                    Mr. Greg Tabor
Eni Petroleum                          Ridgewood Energy Corporation
1201 Louisiana, Suite 3500             11700 Old Katy Road, Suite 280
Houston, Texas 77002                   Houston, Texas 77079


Re:  Topaz Prospect Well Participation Agreement dated July 1, 2005
     East Breaks 157 No.4 (OCS-G 11412 #4)
     East Breaks Blocks 112 & 157, NG 15-1
     GOM


Gentlemen:

Enclosed please find your fully executed original Topaz Prospect Well
Participation Agreement dated July 1. 2005.

Pursuant to the terms of the Topaz Prospect Well Participation Agreement
Woodside respectfully requests that Eni Petroleum prepare and execute
Designation of Operator forms naming Woodside Energy (USA) Inc., GOM number
2407, as the operator of the East Breaks 157 No.4 (OCS-G 11412 #4).

It was a pleasure working with both of you on the Topaz contracts. Let me know
if you require anything further from Woodside.

Best Regards,



/s/ Brad L. Dowdell
Brad L. Dowdell
Director-Land
713-401-0014


<PAGE>
                                                                 [WOODSIDE LOGO]
                                  EXHIBIT "D"
     Attached to and made part of that certain Participation Agreement among
       Eni Petroleum Exploration Co. Inc., Woodside Energy (USA) Inc. and
                                Ridgewood Energy
                    Corporation dated Effective July 1, 2005

                      Topaz AFE East Breaks 157 - Well #4
                      -----------------------------------
RIG POSITIONING DAYS:   2.5 days      SHL:      UTM X:        1,077.753.0 US ft
            D&E DAYS:  32.5 days                UTM Y:       10,100,897.0 US ft
          TOTAL DAYS:  35.0 days      PBHL:     UTM X:        1,077,753.0 US ft
                                                UTM Y:       10,100,897.0 US ft

               DEPTH:  12,000    ft MD                                    AFE #
                       12,000    ft TVD             Rig: Unknown
         WATER DEPTH:  940       ft            Rev Date:  06/23/05        -----

Assumptions:
1. Straight hole to 12,000 ft MD/TVD
2. Wireline logs at TD.
<TABLE>
                                                         Drill, Evaluate, T&A           Total
DESCRIPTION                          Rig Mob / Demob         Original Hole          Original Hole
-------------------------------------------------------------------------------------------------
   Section 1 : Time Sensitive
   --------------------------
<C>                                          <C>                 <C>                    <C>
 1 Rig Rate                                  312,500             4,062,500              4,375,000
 2 Support Vessels                           228,750               633,750                862,500
 3 Woodside Supervision                        7,500                97,500                105,000
 4 Well Site G&G                                   0                     0                      0
 5 Aviaton                                    13,750               178,750                192,500
 6 Mud Logging                                     0                19,200                 19,200
 7 Mud Engineering                                 0                46,313                 46,313
 8 Cementing Services                          7,625               124,125                131,750
 9 Communications                              2,250                29,250                 31,500
10 Solids Control                                  0                     0                      0
11 Diving/ROV                                 10,000               130,000                140,000
12 Directional Drilling                            0               132,500                132,500
13 Wellhead Services                               0                     0                      0
14 Metocean                                      750                 9,750                 10,500
16 Completion and Workover Services                0                     0                      0
17 Supply Base                                 8,750               113,750                122,500
19 Rental Tools                                8,625               112,125                120,750
20 Fishing/Cutting Services                        0                50,000                 50,000
21 Rig Contractor Additional Charges           3,750                48,750                 52,500
   Contingency 20%                           120,850             1,157,653              1,278,503
-------------------------------------------------------------------------------------------------
Total Time Sensitive                         725,100             6,945,915              7,671,015

   Section 2 : Non Time Sensitive
   ------------------------------
22 Rig Positioning                           103,000                     0                103,000
23 Site Survey                                     0                25,000                 25,000
24 HSE                                             0                     0                      0
25 Studies/Analysis                                0               125,000                125,000
26 Wireline Logging                                0               178,000                178,000
27 Coring                                          0                     0                      0
28 Freight and Materials Handling              5,000                65,000                 70,000
29 Tubular Running Services                        0               120.000                120,000
30 Inspection and refurbishment                    0                40,000                 40,000
   Contingency 20%                            21,600               110,600                132,200
-------------------------------------------------------------------------------------------------
Total Non Time Sensitive                     129,600               663,600                793,200

   Section 3 : Tangibles & Consumables
   -----------------------------------
31 Wellhead Equipment                              0               287,200                287,200
32 Tubulars                                        0             1,085,700              1,085,700
33 Tubular Accessories                             0                45,000                 45,000
34 Mud and Chemicals                               0               800,000                800,000
35 Cement and Additives                            0               265,000                265.000
36 Drill Bits                                      0                90,200                 90,200
37 Completion Consumables                          0                     0                      0
38 Solids Control Equipment                        0                     0                      0
39 Rig Consumables                                 0                 5,000                  5,000
40 Fuel                                       79,750               464,750                544,500
   Contingency 20% on consumables             15,950               324,990                340,940
-------------------------------------------------------------------------------------------------
Total Tangibles & Consumables                 95,700             3,367,840              3,463,540

   Section 4 : Administration
   --------------------------
41 Overhead                                    4,752                54,949                 59,701
42 Training                                        0                     0                      0
43 Travel                                          0                12,544                 12,544
-------------------------------------------------------------------------------------------------
   Total Administration                        4,752                67,493                 72,245
                                -----------------------------------------------------------------
                                AFE Total $  955,152         $  11,044,848          $  12,000,000
                                =================================================================

                                        Well Ownership              %WI            TOTAL COST
                                --------------------------------------------------------------
                                Woodside Energy - USA Inc.        37.5000           $4,500,000
                                ENI Petrolium                     25.0000           $3,000,000
                                Ridgewood Energy                  37.5000           $4,500,000
                                --------------------------------------------------------------
                                                       Total     100.0000          $12,000,000
                                --------------------------------------------------------------
</TABLE>

PREPARED BY:  ___________________________  ___________________________
              DRILLING ENGINEER            DATE
APPROVED BY:  ___________________________  ___________________________
              OPERATIONS MANAGER           DATE
              ___________________________  ___________________________
              PRESIDENT                    DATE
APPROVED BY:  ___________________________  ___________________________
              JOINT OPERATED PARTNER       DATE

<PAGE>

                             PARTICIPATION AGREEMENT

THIS PARTICIPATION AGREEMENT is entered into effective this 1st day of July,
2005, by and between, WOODSIDE ENERGY (USA) INC., a corporation organized and
existing under the laws of the State of Delaware, U.S.A. (hereinafter referred
to as "Woodside"), RIDGEWOOD ENERGY CORPORATION, a corporation organized and
existing under the laws of the State of Delaware, U.S.A (hereinafter referred to
as "Ridgewood) and ENI PETROLEUM EXPLORATION CO. INC., a corporation organized
and existing under the laws of the State of Delaware, U.S.A., (hereinafter
referred to as "Eni").

For and in consideration of the mutual covenants set forth herein and other good
and valuable consideration, Woodside, Ridgewood and ENI hereby agree as follows:


                                   ARTICLE I.
                                   DEFINITIONS

As used in this agreement, the following terms shall have the meanings set forth
below:

1.1     "Accounting Procedure" means the rules, provisions and conditions set
        forth in Exhibit "C" to the Offshore Operating Agreement.

1.2     "Affiliate" means a company or partnership or other legal entity which
        controls, or is controlled by, or which is controlled by an entity which
        controls, a Party. Control means the ownership directly or indirectly of
        more than fifty percent (50%) of the voting rights in a company,
        partnership or legal entity.

1.3     "Agreed Interest Rate" means the rate set forth in Article 3.B. of the
        Accounting Procedure.

1.4     "Agreement" means this Agreement, together with the Exhibits attached to
        this Agreement, and any extension, renewal or amendment hereof agreed to
        in writing by the Parties.

1.5     "AFE" means the Authorization for Expenditure submitted by Woodside in
        the gross amount of $ 12,000,000.00 to cover the estimated costs to
        drill the Test Well, which is attached as Exhibit "D".

1.6     "Casing Point" means that point in time when the Test Well has reached
        the Objective Depth (as hereinafter defined) from the surface location
        and at the bottom hole location as originally proposed and after all
        open hole logs, cores and other tests included in the AFE for such well,
        or as the Parties may otherwise mutually agree, have been conducted.

1.7     "East Breaks 112 Unit Participating Areas" means each of (i) the
        Participating Areas in the East Breaks 112 Unit, being 900 acres located
        in East Breaks Block 112, but limited to the sand reservoir outline as
        depicted on Exhibit B, and further limited to the stratigraphic
        equivalent of the interval shown on Exhibit B-1 as depicted on the
        electric log of the East Breaks 112 No.3 Well as the "E" Sand Reservoir
        and (ii) the Participating

                                       1
<PAGE>

        Area in East Breaks Block 157, being 2250 acres located in East Breaks
        157, but limited to the sand reservoir outline(s) as depicted on Exhibit
        B, and further limited to (a) the stratigraphic equivalent of the
        interval shown on Exhibit B-1 as depicted on the electric log of the
        East Breaks 157 No. 2 Well as the "A" Sand Reservoir and (b) the
        stratigraphic equivalent of the interval shown on Exhibit B-1 as
        depicted on the electric log of the East Breaks 157 No. 1 Well as the
        "B" and "C" Sand Reservoirs, as each of the Participating Areas may
        after the Effective Date be enlarged.

1.8     "Excluded Area" means that area within East Breaks Blocks 112 and 157
        that is comprised of the East Breaks 112 Unit Participating Areas, as
        limited in Article 1.7 above, as such exists at the Effective Date and
        as the same may be expanded after the Effective Date of this Agreement.

1.9     "Leases" means the federal oil and gas leases as identified in Exhibit
        "A."

1.10    "MMS" means the Minerals Management Service or any successor
        organization thereto having authority to issue and regulate federal oil
        and gas lease activity in the Outer Continental Shelf.

1.11    "Offshore Operating Agreement" means the instrument attached as Exhibit
        "C."

1.12    "Party" or "Parties" means any of the entities named in the first
        paragraph to this Agreement and any respective permitted successors or
        assigns.

1.13    "Operator" means Woodside for the drilling and plugging or temporary
        abandonment of the Test Well and Eni for the tie back operations and
        subsequent completion and development drilling.

1.14    "Subject Interests" means an undivided twenty-five percent (25%)
        operating rights interest to be earned by each of Woodside and Ridgewood
        and assigned by Eni to each of Woodside and Ridgewood in and to the
        Leases less and except the Excluded Area.

1.15    "Topaz" is the name of the geological prospect to be evaluated by the
        Test Well that is drilled pursuant to this Agreement.

1.16    "Well Participating Area" means the area for which the Subject Interests
        will apply and is to include all of East Breaks Blocks 112 and 157, less
        and except the Excluded Area,


                                     ARTICLE II.
                                      TERM

2.1     This Agreement shall continue in force and effect and be binding upon
        the Parties for a period commencing upon the effective date and expiring
        July 1st, 2006. This Agreement shall also be amended and renewed by
        mutual agreement of the parties.

                                       2
<PAGE>

                                   ARTICLE III
                                DRILLING PROGRAM

3.1     Eni represents, without warranty of title, except by, through and under
        Eni, that it is the owner of one hundred percent (100%) record title
        interest in the Leases, and that the Subject Interests (as defined in
        1.14) to be earned by Woodside and Ridgewood pursuant to this Agreement
        shall be free and clear of all liens, claims and encumbrances. The
        Leases, as to all depths, described on Exhibit "A" comprise all of and
        are subject to the East Breaks 112 Unit (Unit No. 754391005).

3.2     Subject to rig availability and acquisition of all required permits and
        approvals, by Eni as operator of the East Breaks 112 Unit, on or before
        the 1st day of December, 2005, Woodside, as designated Operator, will
        commence and thereafter diligently conduct operations to drill or cause
        to be drilled, an exploratory test well on East Breaks Block 157 at a
        surface and bottom hole location of X =1,077,753 feet and Y = 10,100,897
        feet UTM to a minimum total depth of 12,000 feet MD/TVD ("Objective
        Depth") or such greater depth as may be mutually agreed by the Parties
        to evaluate Eni's Topaz prospect (hereinafter referred to as "Test
        Well"). Woodside and Ridgewood will each pay thirty-seven and
        five-tenths percent (37.5%), being a combined seventy-five percent (75%)
        of the estimated dry hole cost to drill the Test Well to Casing Point or
        through the plugging or temporary abandonment to earn an undivided
        twenty-five percent (25%) each, being a combined fifty percent (50%)
        operating rights (as described in 3.3) in the Leases. The costs to drill
        the Test Well (or its substitute), on which Woodside and Ridgewood bear
        a disproportionate share is limited to the actual drilling cost to reach
        Casing Point, or through plugging and abandoning if a dry hole, or $
        13.2 million dollars, whichever is less ("Cap Amount") based on 110% of
        Woodside's AFE which is defined in Article 1.5 and attached as Exhibit
        "D". Thereafter, Woodside and Ridgewood will each pay their prorata
        twenty-five percent (25%) working interest shares of any well costs in
        excess of the Cap Amount and all other costs incurred from and after the
        Effective Date (including P&A cost) in accordance with the terms of the
        Offshore Operating Agreement attached as Exhibit "C".

3.3     Upon satisfaction by Woodside and Ridgewood of their obligations to
        drill the Test Well to Casing Point or spend up to 110% of the AFE and
        subject to the further provisions of this Article 111, Eni shall assign
        to Woodside and Ridgewood each an undivided twenty five percent (25%)
        operating rights interest in and to the Leases less and except the
        Excluded Area. The Subject Interests being assigned to Woodside and
        Ridgewood shall be subject only to their proportionate share of the
        Lessor's royalty and no other burdens. The assignment of Operating
        Rights, if approved by the MMS, shall be made without warranty of title
        except by, through and under Eni and will be on a mutually acceptable
        form.

        3.3.1   The Assignment shall become validated upon the following:

                A.  Woodside and Ridgewood receiving approval from the MMS of
                    the separate transfer and assignment of operating rights by
                    Eni to Woodside and Ridgewood of the Subject Interests in
                    accordance with all laws, rules and regulations applicable
                    thereto and

                                       3
<PAGE>

                B.  Any assignment of Subject Interests or portion thereof that
                    is not approved by the MMS will be handled in a manner that
                    is mutually acceptable to the Parties to effect the transfer
                    of the Subject Interests.

        Upon fulfillment of the foregoing conditions, the Assignments shall be
        effective retroactive to the Effective Date.

        3.3.2   Concurrently with Woodside and Ridgewood's execution of this
                Agreement Eni shall execute and deliver to Woodside the
                necessary "Designation of Operator" forms (MMS Form 1123)
                designating Woodside as the Operator of the Test Well subject to
                this Agreement, along with any other documents required to allow
                a Party to serve as Operator under the Offshore Operating
                Agreement or applicable regulations.

        3.3.3   The Assignments shall convey only the Subject Interests and ENI
                shall not assign, either its Geoscience Data or its Intellectual
                Property. as hereinafter defined.

                A.  Geoscience Data: All of Eni's ownership interest in any
                    geological, geochemical or geophysical data,
                    interpretations, maps, reports, geohazard surveys, or other
                    information or derivatives of this information related to
                    the Leases (the "Data");

                B.  Intellectual Property: All of Eni's ownership interest in
                    any inventions, patents, copyrights, trademarks and other
                    intellectual property related to the Leases.

                The provision of this Article 3.3.3 shall extend beyond the term
                of this Agreement.

        3.3.4   Woodside and Ridgewood agree to reimburse Eni for their
                proportionate share of all Leasehold maintenance costs, i.e.
                rentals and minimum royalties accruing under the terms of the
                Leases beginning as of the Effective Date of this Agreement for
                the next ensuing year and continuing, as to each such lease, for
                so long as the Lease remains subject to this Agreement.

3.4     If prior to reaching the Objective Depth for the Test Well, a decision
        is made in accordance with the terms of the Offshore Operating Agreement
        to abandon the well due to the existence of Gulf Coast Conditions as
        defined in the Offshore Operating Agreement, then any well (i) proposed
        in. accordance with the Offshore Operating Agreement to test the same
        prospect as planned in the Test Well, and (ii) commenced within one
        hundred and twenty (120) days of the abandonment of the Test Well, shall
        be considered to be a substitute well for the Test Well. Each Party
        shall have the option (not obligation) to continue participation as per
        the Offshore Operating Agreement. All the provisions of this Agreement
        shall apply to such well with the same force and effect as to the
        abandoned well, provided, Woodside and Ridgewood's cost bearing share
        shall be reduced from seventy-five percent (75%), being 37.5% each to
        fify percent (50%), being (50%), being 25% percent each when the

                                       4
<PAGE>

        combined total costs of the Test Well and substitute well equal $13.2
        million.

3.5     Upon reaching Casing Point, each Party shall have the election as to
        their respective working interests (Eni 50%, Woodside 25%, Ridgewood
        25%) of either:

        (1)     conducting further operations in the Test Well, i.e. deepening,
                side-tracking, or completing the Test Well, in accordance with
                the priority for such operations set forth in the Offshore
                Operating Agreement, to be shared in the proportions of Eni 50%,
                Woodside 25%. Ridgewood 25%, or

        (2)     plugging and abandoning or temporarily abandoning of the Test
                Well to be shared in the proportion of Eni 25%, Woodside 37.50%
                and Ridgewood 37.50% subject to the cap of Section 3.4.

        The notice and elections shall be made in accordance with the terms and
        conditions of Article 10.8 of the Offshore Operating Agreement attached
        as Exhibit "C".

3.6     A material default to drill the Test Well by Woodside and/or Ridgewood
        in performing the obligations as provided under this Article shall
        constitute a breach of this Agreement. A material default shall not give
        rise to Eni's right to terminate the contract unless the defaulting
        Party(ies) fails to cure such default within thirty (30) days of
        receipt from Eni of written notice stating the specifics of the default,
        or the defaulting Party's failure to commence the cure of such default
        and thereafter to prosecute such operations with due diligence to
        completion if the default cannot be cured within such time period.

3.7     In no event, shall any Party hereto be responsible to any other Party
        for consequential or punitive damages (including but not limited to loss
        of profit, business interruption and lost business opportunity).

3.8     The Leases and the Test Well drilled hereunder, shall be operated in
        accordance with the Offshore Operating Agreement which is attached
        hereto as Exhibit "C" and incorporated herein by reference. If any
        conflict exists between this Agreement and the Offshore Operating
        Agreement, this Agreement shall control. Eni shall remain the designated
        Operator of the Leases and Woodside shall, with Eni's assistance,
        attempt immediately to obtain all necessary governmental approvals and
        permits to drill the Test Well.


                                   ARTICLE IV.
                                   ASSIGNMENTS

4.1     No Party to this Agreement may assign all or any part of its interest in
        this Agreement without the prior written consent of the other Parties
        hereto, except that any Party may assign all or any part of its interest
        to an Affiliate upon giving prior notice to the other Parties and
        agreeing to remain liable for all of its obligations arising under this
        Agreement. Such granting of consent to a financially responsible party
        qualifying to hold leases with the MMS, shall not be unreasonably
        withheld. Notwithstanding the foregoing, Woodside shall have the right
        to assign to Explore Louisiana LLC all or part of its (Woodside's)

                                       5
<PAGE>

        interests in (i) this Well Participation. Agreement, (ii) the Offshore
        Operating Agreement, and (iii) the earned Subject Interests (whether
        those interest be Operating Rights Interests or other mutually
        acceptable interests).


                                   ARTICLE V.
                             RELATIONSHIP OF PARTIES

5.1     The rights, duties, obligations and liabilities of the Parties under
        this Agreement shall be individual, but limited initially to the
        percentage each party is to pay for the drilling of the Test Well and
        thereafter to its respective and proportionate share of the Subject
        Interests earned and either assigned or assignable to it, and not joint
        and several. It is not the intention of the Parties to create, nor shall
        this Agreement be deemed or construed to create a mining or other
        partnership, joint venture, association or trust. This Agreement shall
        not be deemed or construed to authorize any Party to act as an agent,
        servant or employee for any other Party for any purpose whatsoever and
        in their relations with each other under this Agreement, the Parties
        shall not be considered fiduciaries.


                                   ARTICLE VI.
                                 CONFIDENTIALITY

6.1     All data and information acquired, interpreted, developed or disclosed
        pursuant to this Agreement shall be held confidential by all Parties in
        accordance with the confidentiality provisions of the Offshore Operating
        Agreement, Exhibit C. All other confidentiality provisions and/or
        agreements between the Parties being that certain Confidentiality
        Agreement between Eni and Woodside dated March 22, 2005 and that
        certain Confidentiality Agreement between Eni and Ridgewood dated May 2,
        2005, covering Subject Interests shall terminate and be superceded by
        the confidentiality provision of Exhibit "C".


                                  ARTICLE VII.
                                     NOTICES

7.1     All notices authorized or required between the Parties shall be
        addressed and effective when delivered to such persons as designated
        below. Each Party shall have the right to change its address at any time
        and/or designate that copies of all such notices be directed to another
        person at another address, by giving notice thereof to the other
        Parties:


                        Eni Petroleum Exploration Co Inc.
                        1201 Louisiana
                        Suite 3500
                        Houston, Texas 77002
                        Attn:  Charles C. Barnes
                        Phone: 713.393.6107
                        Fax:   713.363.6208

                                       6
<PAGE>

                        Woodside Energy (USA) Inc.
                        Sage Plaza, 5151 San Felipe,
                        Suite 1200
                        Attn: Leon Hirsch
                        Houston, Texas 77056
                        Phone: 713.413.0021
                        Fax:   713.963.8868


                        Ridgewood Energy Corporation
                        11700 Old Katy Road, Suite 280
                        Houston, Texas 77079
                        Attn: Greg Tabor
                        Phone: 281.293.8449
                        Fax:   281.293.7705



                                  ARTICLE VIII.
                                 APPLICABLE LAW

8.1     This Agreement shall be governed by, construed, interpreted and enforced
        in accordance with the substantive laws of the State of Texas, to the
        exclusion of any conflicts of law rules that would refer the matter to
        the laws of another jurisdiction. Venue for any litigation arising from
        this Agreement shall be in Harris County, Texas.



                                   ARTICLE IX.
                             AREA OF MUTUAL INTEREST

9.1     In the event any party acquires an interest in an oil and gas lease
        covering the Offshore Blocks described on Exhibit "A" (hereinafter
        referred to as "AMI Blocks"), or acquires any right to acquire an
        interest in an oil and gas lease covering the AMI Blocks or any portion
        thereof ("Acquiring Party") within the term of this Agreement, then the
        other Parties shall each have the right, but not the obligation, to
        acquire from the Acquiring Party it's non promoted share (Eni 50%,
        Woodside 25% and Ridgewood 25%) of the interest and/or right acquired.
        The other Parties shall each be notified in writing by the Acquiring
        Party within fifteen (15) days of such acquisition and shall have thirty
        (30) days after receipt of such notice to advise Acquiring Party whether
        or not it elects to acquire it's share of the interest and/or right
        acquired. In the event that a Party fails to give such responsive notice
        within the aforesaid thirty (30) day period, such failure shall be
        conclusively deemed to be an election not to acquire a share of the
        interest or rights acquired by Acquiring Party. Said notice is to
        include the actual acquisition costs if any, and other consideration
        offered (which shall include the monetary equivalent in U.S. Dollars
        based upon reasonable market value of any consideration other than cash)
        if any, and any obligations relative to the acquisition. If a Party


                                       7
<PAGE>

        elects to exercise its right under this Agreement, the consideration
        owed by the Party shall equal it's share of the actual costs and/or
        obligations paid and/or assumed for the acquired interest.


                                   ARTICLE X.
                               GENERAL PROVISIONS

10.1    Subject to the limitations on transfer contained in Article V., this
        Agreement shall inure to the benefit of and be binding upon the
        successors and assigns of the Parties.


10.2    No waiver by a Party of any one or more breaches or defaults by another
        party in the performance of this Agreement shall operate or be construed
        as a waiver of any future breach(s) or default(s) by the same Party
        whether of a like or of a different character. Except as expressly
        provided in this Agreement no Party shall be deemed to have waived,
        released or modified any of its rights under this Agreement unless such
        Party has expressly stated, in writing, that it does waive, release or
        modify such right.

10.3    If and for so long as any provision of this agreement shall be deemed to
        be judged invalid for any reason whatsoever, such invalidity shall not
        affect the validity or operation of any other provision of this
        Agreement except only so far as shall be necessary to give effect to the
        construction of such invalidity, and any such invalid provision shall be
        deemed severed from this Agreement without affecting the validity of the
        Agreement.

10.4    There shall be no modification of this Agreement except by written
        consent of all Parties.

10.5    Reference to the singular includes a reference to the plural and vice
        versa.

10.6    The topical headings used in this Agreement are for convenience only and
        shall not be construed as having any substantive significance or as
        indicating that all of the provisions of this Agreement relating to any
        topic are to be found in any Article.

10.7    This Agreement is the entire agreement of the Parties with respect to
        the subject matter contained herein and supersedes all prior
        understandings and negotiations of the Parties.

IN WITNESS of their agreement each Party has caused its duly authorized
representative to sign this instrument on the date indicated below such
representative's signature. This Agreement may be executed in one or more
counterpart copies and shall be effective as of the Effective Date first above
written.


                                       8
<PAGE>



ENI PETROLEUM EXPLORATION CO. INC.          RIDGEWOOD ENERGY CORPORATION


By: /s/ Charles C. Barnes                   By: /s/ W. G. Tabor
    ---------------------                       ---------------

Name: Charles C. Barnes                     Name: W. Greg Tabor
                                                  -------------

Title: Attorney-in-Fact                     Title: Executive VP
                                                   ------------

Date: 8-30-05                               Date: 9-2-05
      -------                                     ------


WOODSIDE ENERGY (USA) INC.

By: /s/ David M. McCubbin
    ---------------------

Name: David M. McCubbin
      -----------------

Title: President
       ---------

Date: 9-7-05
      ------


                                       9
<PAGE>

                                   Exhibit "A"
    Attached to and made a part of that certain Participation Agreement among
       Eni Petroleum Exploration Co. Inc., Woodside Energy (USA) Inc. and
            Ridgewood Energy Corporation dated effective July 1, 2005


I.   Description of Leases
     ---------------------

     a.   Oil and Gas Lease bearing Serial No. OCS-G 08195, effective November
          1, 1985 between the United States of America, as Lessor, and Agip
          Petroleum Co. Inc. and Union Texas Petroleum Corporation, as Lessees,
          covering approximately 4847.75 acres, being all of Block 112, East
          Breaks, as shown on OCS Official Protraction Diagram NG 15-1.

<TABLE>
<CAPTION>
         Current Owners                    Working Interest     Net Revenue Interest
         --------------                    ----------------     --------------------
<S>                                             <C>                  <C>
         Eni Petroleum Exploration Co. Inc.     100.00%              83.3333%

     b.   Oil and Gas Lease bearing Serial No. OCS-G 11412, effective October 1,
          1989 between the United States of America, as Lessor, and Agip
          Petroleum Co. Inc. and Union Texas Petroleum Corporation, as Lessees,
          covering approximately 5760.00 acres, being all of Block 157, East
          Breaks, as shown on OCS Official Protraction Diagram NG 15-1.

<CAPTION>

         Current Owners                    Working Interest     Net Revenue Interest
         --------------                    ----------------     --------------------
<S>                                             <C>                  <C>
         Eni Petroleum Exploration Co, Inc.     100.00%              83.3333%
</TABLE>

II.  Depth Limitations within the Leases described in I. above derived from
     Participating Areas attributable to the East Breaks 112 Unit, OCS Unit No.
     754391005.

     a.   OCS-G 01895, East Breaks Block 112:
          -----------------------------------
          This Participation Agreement is limited to those rights in East Breaks
          Block 112 that are located within the Well Participating Area as
          defined herein under Article 1.16. Within said Well Participating Area
          the depths excluded from this Participation Agreement consist of the
          stratigraphic equivalent of the intervals depicted on the electric log
          of the East Breaks 112 No. 3 Well as the "E" Sand Reservoir as further
          depicted on Exhibit "B" and defined in Exhibit "B-1".

     b.   OCS-G 11412, East Breaks Block 157:
          ------------------------------------
          This Participation Agreement is limited to those rights in East Breaks
          Block 157 that are located within the Well Participating Area as
          defined herein under Article 1.16. Within said Well Participating Area
          the depths excluded from this Participation Agreement consist of 1)
          the stratigraphic equivalent of the interval depicted on the electric
          log of the East Breaks 157 No. 2 Well as the "A" Sand Reservoir as
          further depicted on Exhibit "B" and defined in Exhibit "B-l", and 2)
          the stratigraphic equivalent of the intervals depicted on the electric
          log of the East Breaks 157 No. 1 Well as the "B" and "C" Sand
          Reservoir as further depicted on Exhibit "B" and defined in Exhibit
          "B-1". The "B" and "C"


                                       10
<PAGE>



          reservoirs will require an expansion of the Unit Participating Area
          for the East Breaks 157 Lease (Proposed Revised Unit Outline)
          resulting in the exclusion of the additional outline area covering the
          acreage(s) as depicted on Exhibit "B" and further define on Exhibit
          "B-1" to be added as the Proposed Revised Unit Outline.

The Excluded Area and Reservoirs Associated with the East Breaks 112 Unit are
further depicted on the map and the Schedule of Depth reservations attached
hereto as Exhibits "B" and "B-I".


III. AREA OF MUTUAL INTEREST (AMI) BLOCKS REFERRED TO IN ARTICLE IX. OF THE
     ---------------------------------------------------------------------
     PARTICIPATION AGREEMENT ARE AS FOLLOWS:
     ---------------------------------------


--------------------------------------------------------------------------------
   AREA/BLOCK           LEASE NO.                 OWNER             EXPIRATION
--------------------------------------------------------------------------------
East Breaks 113         OCS-G 22278          Unocal                  09/30/2005
--------------------------------------------------------------------------------
East Breaks 114         OPEN                        -                    -
--------------------------------------------------------------------------------



                                       11
<PAGE>

                                   Exhibit "B"
  Attached to and made part of that certain Participation Agreement among Eni
Petroleum Exploration Co. Inc., Woodside Energy (USA) Inc. and Ridgewood Energy
                    Corporation dated Effective July 1, 2005

                           EAST BREAKS BLOCK 112 UNIT
                       PARTICIPATING AREAS AND APPLICABLE
                             RESERVOIR OUTLINES FOR
                      PARTIAL BLOCKS EAST BREAKS 112 & 157

                                  [MAP OMITTED]





<PAGE>

                                  EXHIBIT "B-1"
 Attached to and made a part of that certain Participation Agreement among Eni
Petroleum Exploration Co. Inc., Woodside Energy (USA) Inc. and Ridgewood Energy
                    Corporation dated Effective July 1, 2005



EAST BREAKS 112 UNIT DEPTH EXCLUSIONS:



E sand Reservoir in Agip EB 112 #3:   Top 7321'MD 6122'TVD       -6050' SS
                                      Base 7379'MD 6168'TVD      -6096' SS




A sand Reservoir in Agip EB 157 #2:   Top 4916'MD & TVD          -4843' SS
                                      Base 5045'MD & TVD         -4972' SS




B sand Reservoir in Agip EB 157 #1:   Top 5520'MD & TVD          -5436' SS
                                      Base 5696'MD & TVD         -5612' SS




C sand Reservoir in Agip EB 157 #1    Top 6187'MD & TVD          -6103' SS
                                      Base 6398'MD &TVD          -6304' SS