**Exhibit
        10.6**

# PARTICIPATION
        AGREEMENT

This
        Participation Agreement is made and entered into this _____ day of November 2007, but
        effective November 9, 2007, by and between W & T Offshore, Inc., hereinafter referred
        to as (“W&T”) and Ridgewood Energy Corporation, hereinafter referred to as
        (“Ridgewood”), and collectively referred to herein as the Parties.

# WITNESSETH:

WHEREAS, W&T is an owner of certain record title interests and holds contractual
        rights in and to certain Federal Oil and Gas Leases as fully described on Exhibit
        “A”, attached hereto and the lands covered thereby, hereinafter referred to as
        the “Leasehold Rights”, and

WHEREAS, W&T and Merit Management Partners I, L.P., Merit Management Partners II,
        L.P., Merit Management Partners III, L.P., Merit Energy Partners D-III, L.P., Merit Energy
        E-III, L.P., and Merit Energy Partners F-III, L.P. (“Merit”) and W & T
        Offshore, Inc. have executed that certain Co-Development Agreement dated and effective
        August 31, 2007 which is attached hereto as Exhibit “B” and made a part hereof
        (“Co-Development Agreement”) covering the North-half of the North-half (N/2
        N/2) of High Island Block 38, limited to those depths below the stratigraphic equivalent of
        12,900’ SSTVD, and the South-half of the Southeast-quarter (S/2 SE/4) of Sabine Pass
        Block 18, limited to those depths below the stratigraphic equivalent of 12, 900’
        SSTVD (“the Co-development Area”), and

WHEREAS,
        under the terms of the Co-Development Agreement W&T and Merit have committed to the
        drilling of the Initial Exploratory Well, which is defined hereinafter in Article II.A.;
        and

WHEREAS,
        W&T represents that it owns 100% of the rights in and to that certain Farmout Agreement
        dated effective August 31, 2007 by and between El Paso E&P Company, L.P and W&T
        Offshore, Inc., covering the South-half of the Southeast-quarter (S/2 SE/4) of Sabine Pass
        Block 18, limited to those depths below the stratigraphic equivalent of 12, 900’
        SSTVD, which is attached hereto and made a part hereof as Exhibit “C”
        (“Farmout”); and

WHEREAS, W&T and Ridgewood have executed that certain Offer to Participate
        effective November 9, 2007 by which Ridgewood may acquire a twenty-five percent of
        eight-eighths (25% of 8/8ths) interest in and to the Farmout and Co-Development
        Agreement;

NOW
        AND THEREFORE, for and in consideration of the mutual promises hereinafter contained,
        W&T and Ridgewood agree as follows:

1



---



ARTICLE
        I

|A. |  | Under
                    the terms and conditions of the Co-Development Agreement, W&T represents
                    that it owns a 77.60% of 8/8ths working interest in and to the Initial
                    Exploratory Well and the Leasehold Rights within Co-Development Area; further,
                    the Co-Development Agreement, among other things, provides that W&T has
                    full power and authority to assign an interest to Ridgewood as to the rights
                    and obligations thereunder.
|-- |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|   |  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              
|B. |  | W&T
                    represents that it owns 100% of the rights in and to that certain Farmout,
                    which provides, among other things, that W&T has full power and authority
                    to assign an undivided interest to Ridgewood as to the rights and obligations
                    thereunder.                                                                                                                                                                                                           

|C. |  | W&T represents by,
                    through and under its own acts that W&T’s interest in the Farmout is
                    free and clear of all liens and encumbrances, less and except Lessor’s
                    royalty, and the overriding royalty interest retained under the terms of the
                    Farmout.
|-- |  | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|D. |  | Upon the
                    execution of this Participation Agreement, W&T hereby assigns and conveys
                    unto Ridgewood an undivided 85.22728% interest in and to the contractual rights
                    of the Farmout (which is equivalent to a twenty-five percent of eight-eighths
                    (25.00% of 8/8ths) interest in and to the Co-Development Area), which interest
                    is expressly subject to the terms and conditions of the Co-development
                    Agreement (hereinafter defined as the “Ridgewood
                    Interest”).
|-- |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|E. |  | Upon the
                    execution of this Participation Agreement, Ridgewood hereby ratifies, adopts
                    and accepts all of the terms and conditions of the Farmout and the
                    Co-Development Agreement.
|-- |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|F. |  | Within
                    three (5) business days from the execution of this Participation Agreement,
                    Ridgewood agrees to wire transfer $6,960,395.00 which represents an advance
                    payment under the terms of the CDOA for its 33.33333% share of the Total AFE
                    Drilling & Evaluation costs. Such payment should be wired to:
|-- |  | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | Account Name:   |  | W & T Offshore, Inc.                            | 
| | --------------- |  | ----------------------------------------------- | 
| | Street Address: |  | Nine Greenway Plaza, Suite 300Houston, TX 77046 | 
| | Recipient Bank: |  | Amegy Bank                                      | 
| | ABA Routing #   |  | 113-011-258                                     | 
| | Account #       |  | 51581996                                        | 

| | W &
                T’s Tax I.D. Number is 72-1121985. W&T shall have the sole option to
                terminate this Participation Agreement if such payment is not received
                timely.
| | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

2

---

ARTICLE
        II

|A. |  | Ridgewood acknowledges that
                    the Ridgewood Interest is subject to the Co-Development Agreement, which among
                    other things, obligates Ridgewood to participate in all of the costs, risk and
                    expenses associated with the drilling of the OCS-G 14878 Well No. 2 to a bottom
                    hole location at 5,635.81’ FEL and 820’ FNL of High Island Block
                    38, to a depth of 15,994’ MD/15,130’ TVD, or to a depth sufficient
                    to test the Cristellaria “R” sand (the “Objective
                    Depth”), whichever is the lesser (such well hereinafter referred to as
                    the “Initial Exploratory Well”). Further, as consideration for
                    right to acquire an undivided twenty-five percent (25%) working interest in and
                    to the Farmout and Co-Development Area, Ridgewood agrees to pay thirty-three
                    and one-third percent of eight eighths (33 1/3% of 8/8ths) of all of the costs,
                    risk and expenses in the drilling of the Initial Exploratory Well to
                    “casing point” (as provided by the CDOA), or through plugging and
                    abandonment, if applicable.
|-- |  | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|B. |  | The
                    Initial Exploratory Well will be spud on or before December 31, 2007, and will
                    be drilled and operated in accordance with the terms of that certain
                    Co-development Operating Agreement as provided in the Co-development Agreement
                    (hereinafter referred to as “CDOA”).
|-- |  | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|C. |  | The
                    estimated cost, risk and expense of drilling the Initial Exploratory Well to
                    the Objective Depth is set out in W&T’s AFE No. D07009, attached
                    hereto as Exhibit “D” (hereinafter referred to as the
                    “AFE”). Concurrent with the execution of this Agreement, Ridgewood
                    agrees to execute the AFE.
|-- |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|D. |  | Subject
                    to the terms of the Co-development Agreement and the CDOA, all actual costs
                    associated with the drilling of the Initial Exploratory Well to casing point,
                    or through plugging and abandonment, if applicable, shall be borne as
                    follows:
|-- |  | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | Merit     |  | 22.40000% WI  | 
| | --------- |  | ------------- | 
| | W & T     |  | 44.26667% WI  | 
| | Ridgewood |  | 33.33333% WI  | 
| |           |  |               | 
| |           |  | 100.00000% WI | 



|E. |  | At such
                    time that the Initial Exploratory Well has reached casing point, or, if prior
                    to reaching casing point, the cumulative costs associated with the drilling of
                    the Initial Exploratory Well have exceeded 115% of the cost to drill and
                    evaluate the Initial Exploratory Well (or plug and abandon, if applicable) set
                    out on the AFE (the “DHC Cap”), Ridgewood’s disproportionate
                    cost sharing will cease and as to all further costs associated with the Initial
                    Exploratory Well, Ridgewood’s share of costs will be 25.00%.
                    Ridgewood’s disproportionate cost spending is applicable to the Initial
                    Exploratory Well, or any Substitute Well (as such term is defined in the
                    Co-Development Agreement); thereafter, subsequent wells or operations conducted
                    under the terms of Co-development Agreement will be borne as
                    follows:
|-- |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

3

---

| | Merit     |  | 22.40000% WI  | 
| | --------- |  | ------------- | 
| | W & T     |  | 52.60000% WI  | 
| | Ridgewood |  | 25.00000% WI  | 
| |           |  |               | 
| |           |  | 100.00000% WI | 

|F. |  | Upon the
                    drilling and completion of the Initial Exploratory Well and satisfaction of the
                    terms set forth in (i) this Participation Agreement, (ii) the Co-development
                    Agreement and (iii) the Farmout, and within thirty (30) days from receipt of an
                    assignment from El Paso pursuant to the Farmout, W&T shall deliver to
                    Ridgewood an assignment of the Ridgewood Interest (as described hereinabove),
                    without warranty other than by, through and under W&T but with full
                    substitution and subrogation in and to all covenants and warranties of
                    W&T’s predecessors in title, in a form acceptable to the MMS, of the
                    operating rights interest in Lease OCS-G 04082 derived from the Ridgewood
                    Interest. It is understood and agreed that assignment of operating rights
                    interest to be conveyed to Ridgewood shall deliver a net revenue interest of
                    seventy-five percent, proportionately reduced (which equates to a net revenue
                    interest of 18.75% of 8/8ths to the 25% working interest) of the production
                    recovered from operations conducted under the terms of the Co-development
                    Agreement. Said Assignment of the Ridgewood Interest shall be made subject to
                    the terms of (i) this Participation Agreement, (ii) the Co-development
                    Agreement, (iii) the Farmout, and (iv) the CDOA. Notwithstanding anything to
                    the contrary contained herein, if Ridgewood does not elect to set casing and
                    complete the Initial Exploratory Well for production of oil and/or gas, it
                    shall not be entitled to an assignment of the Ridgewood Interest as provided
                    for herein and Ridgewood’s plugging and abandonment liability shall be
                    limited solely to the Initial Exploratory Well.
|-- |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

ARTICLE
        III

|A. |  | EXCEPT
                    WITH RESPECT TO THE SPECIAL WARRANTY OF TITLE AS SET FORTH IN ARTICLE III (F),
                    W&T HAS NOT MADE, AND W&T HEREBY EXPRESSLY DISCLAIMS AND NEGATES, ANY
                    REPRESENTATION OR WARRANTY, EXPRESS, IMPLIED, BY COMMON LAW, BY STATUTE, OR
                    OTHERWISE RELATING TO (i) THE TITLE OR CONDITION OF THE LEASES AND CONTRACTS
                    DESCRIBED HEREIN, AND (ii) ANY INFORMATION (WHETHER WRITTEN OR ORAL) FURNISHED
                    TO RIDGEWOOD BY OR ON BEHALF OF W&T (INCLUDING WITHOUT LIMITATION, IN
                    RESPECT OF GEOLOGICAL, GEOPHYSICAL AND SEISMIC DATA, THE EXISTANCE OR EXTENT OF
                    OIL, GAS OR OTHER MINERAL RESERVES, ANY PRODUCT PRICING ASSUMPTIONS, Ridgewood
                    irrevocably waives any and all claims it may have against W&T associated
                    with same. This provision does not apply to any specific representations or
                    warranties set forth herein.
|-- |  | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

4

---



|B. |  | Except
                    as otherwise expressly provided herein, the provisions of this Participation
                    Agreement shall inure to the benefit of, and be binding upon, the successors,
                    assigns, heirs, executors and administrators of the Parties hereto.
|-- |  | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|C. |  | Failure
                    by W&T or Ridgewood to enforce any of the provisions of this Participation
                    Agreement shall not effect a waiver of any violation thereof nor preclude
                    enforcement of that or any other provisions hereof at that or any other
                    time.
|-- |  | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|D. |  | This
                    Participation Agreement, including all Exhibits attached hereto, constitutes
                    the full and entire understanding and agreement between the Parties relating to
                    the matters herein, and except as otherwise provided herein, supersedes any
                    previous agreements or understandings, written or oral, in effect between the
                    Parties relating hereto. In the event of any conflict between the Parties
                    regarding the terms and conditions of this (i) Participation Agreement, (ii)
                    the Co-development Area, (iii) the Farmout and/or (iv) the CDOA, the terms and
                    conditions of this Participation Agreement shall prevail and
                    control.
|-- |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|E. |  | For the
                    purposes of notices pursuant to this Agreement:
|-- |  | ---------------------------------------------------------------------------

| |                                |                                |            |                        
| | ------------------------------ | ------------------------------ | ---------- | -----------------------
| | Ridgewood Energy Corporation   | W & T Offshore, Inc.          
| | 11700 Old Katy Road, Suite 280 | Nine Greenway Plaza, Suite 300
| | Houston, Texas 77079           | Houston, Texas 77046          
| | Attention:                     | W. Greg Tabor                  | Attention: | Jeanette Wilkins       
| | Phone:                         | 281.293.8488                   | Phone:     | 713.624.7307           
| | Fax:                           | 281.293.7391                   | Fax:       | 713.624.7378           
| | E-mail:                        | gtabor@ridgewoodenergy.com     | E-mail:    | jwilkins@wtoffshore.com

| | For the
                delivery of data recovered from operations conducted hereunder, Ridgewood’s
                Well Information Requirements are attached hereto as Exhibit “D” and
                made a part hereof.
| | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|F. |  | This Participation
                    Agreement shall not be modified or amended except by mutual agreement of the
                    Parties in writing, and no action or failure to act on the part of either Party
                    hereto shall be construed as a modification or amendment to, or a waiver of,
                    any of the provisions of this Participation Agreement.
|-- |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|G. |  | This
                    Agreement shall be governed by and construed in accordance with the laws of the
                    State of Texas, without giving effect to its conflicts of law provisions. Venue
                    for any claim or causes of action brought under this Participation Agreement
                    shall be in Harris County, Texas.
|-- |  | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|H. |  | This
                    Agreement shall represent the full and final agreement between the Parties and
                    shall supersede any prior agreement, whether written or oral, regarding the
                    business transaction that is the subject hereof.
|-- |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

5

---



|I. |  | This Participation
                    Agreement is not intended to and shall not be construed to create any mining
                    partnership, commercial partnership, any other partnership or an association
                    for profit between or among the Parties.
|-- |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|J. |  | All
                    notices, requests, demands, and other communications provided for or permitted
                    hereunder shall be in writing (including telex and telecopy communications) and
                    shall be sent by mail, telex, telecopier or hand delivered as provided in
                    Exhibit “A”. Said notices, requests, demands and communications
                    shall be effective upon delivery.
|-- |  | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

IN WITNESS WHEREOF,
        THIS PARTICIPATION AGREEMENT IS MADE EFFECTIVE AS OF THE EFFECTIVE DATE ABOVE
        WRITTEN.

|         |  |                              |                         
|-------- |  | ---------------------------- | ------------------------
|Witness: |  | W & T OFFSHORE, INC.        
|         |  |                              |                         
|         |  | By:                          |                         
|         |  |                              |                         
|         |  |                              | Jamie L. Vazquez        
|         |  |                              | Vice-President          
|         |  |                              |                         
|         |  | RIDGEWOOD ENERGY CORPORATION
|         |  |                              |                         
|         |  | By:                          |                         
|         |  |                              |                         
|         |  | Name:                        | W. Greg Tabor           
|         |  | Its:                         | Executive Vice President

6

---

EXHIBIT
        “A”

Attached to and made a part of that certain Participation
        Agreement
dated the ______ of November 2007, but effective November
        9, 2007
by and
        between
W & T Offshore,
        Inc. and Ridgewood Energy Corporation

|I. | THE
                    LEASES SUBJECT TO THE CO-DEVELOPMENT AGREEMENT, insofar and only insofar as
                    such Leases are located within the Co-Development Area as described in
                    the Co-development Area, being the North-half of the North-half (N/2 N/2) of
                    High Island Block 38, limited to those depths below the stratigraphic
                    equivalent of 12,900’ SSTVD (representing a fixed 56% Co-Development
                    Allocation Percentage); and the South-half of the Southeast-quarter (S/2
                    SE/4) of Sabine Pass Block 18, limited to those depths below the
                    stratigraphic equivalent of 12, 900’ SSTVD (representing a fixed 44%
                    Co-Development Allocation Percentage):
|-- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (1)    
                    OCS-G 14878: Oil, Gas and Mineral Lease dated November 30, 1999 issued by the
                    U. S. Department of Interior, as Lessor, to Nippon Oil Exploration U.S.A.
                    Limited and The Louisiana Land and Exploration Company, as Lessees, covering
                    all of Block 38, High Island Area, East Addition, as show on OCS Texas Leasing
                    Map, TX7A, and (2) OCS-G 04082: Oil, Gas and Mineral Lease dated October 1,
                    1979 issued by the U. S. Department of Interior, as Lessor to Pogo Production
                    Company and Tenneco Oil Company, as Lessees, covering that portion of Block 18
                    seaward of the Three Marine League Line measured from the historic shoreline
                    described in the United States vs. Louisiana, No. 9 Original (394 U.X. 836),
                    Sabine Pass Area, as shown on OCS Official Leasing Map, Texas Map No.
                    8.
| | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



7

---

**EXHIBIT
        “B”**

Attached to and made
        a part of that certain Participation Agreement 
dated the ______ of November 2007, but effective November 9, 2007
by and between
W & T Offshore,
        Inc. and Ridgewood Energy Corporation



8

---

# EXHIBIT
        “C”

Attached to and made a part of that certain Participation
        Agreement
dated the ______ of November 2007, but effective
        November 9, 2007
        by and between
W & T Offshore,
        Inc. and Ridgewood Energy Corporation



9

---

# EXHIBIT
        “D”

Attached to and made
        a part of that certain Participation Agreement
dated the ______ of November 2007, but effective November 9, 2007 
by and between
W & T Offshore,
        Inc. and Ridgewood Energy Corporation



10

---