Exhibit
      4.18

     

    THIS
      DEBENTURE AND THE COMMON SHARES ISSUABLE UPON CONVERSION OF THIS DEBENTURE
      HAVE
      NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR ANY STATE
      SECURITIES LAWS. THIS NOTE AND THE COMMON SHARES ISSUABLE UPON CONVERSION OF
      THIS NOTE MAY NOT BE SOLD, OFFERED FOR SALE, PLEDGED OR HYPOTHECATED IN THE
      ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT AS TO THIS DEBENTURE UNDER SAID
      ACT AND ANY APPLICABLE STATE SECURITIES LAWS OR AN OPINION OF COUNSEL REASONABLY
      SATISFACTORY TO TRIANGLE PETROLEUM CORPORATION THAT SUCH REGISTRATION IS NOT
      REQUIRED.

     

    CONVERTIBLE
      DEBENTURE

     

    FOR
      VALUE
      RECEIVED, Triangle Petroleum Corporation, a Nevada corporation (the
“Borrower”),
      promises to pay to Centrum Bank AG (the “Holder”)
      or its
      registered assigns or successors in interest, the sum of Two Million Five
      Hundred Thousand Dollars ($2,500,000), together with any accrued and unpaid
      interest hereon, on January 23, 2009 (the “Maturity
      Date”)
      if not
      sooner paid.

     

    Capitalized
      terms used herein without definition shall have the meanings ascribed to such
      terms in that certain Securities Purchase Agreement dated as of December 28,
      2005, between Borrower and the Holder (as amended, modified or supplemented
      from
      time to time, the “Purchase
      Agreement”).

     

    The
      following terms shall apply to this Debenture:

     

    ARTICLE
      I

    INTEREST
      & AMORTIZATION

     

    1.1.  Contract
      Rate.
      Subject
      to Sections 4.11 and 6.7 hereof, interest payable on this Debenture shall accrue
      at a rate per annum equal to seven and one-half percent (7.5%) (the
“Contract
      Rate”).
      

     

    1.2.  Payments.
      Payment
      of the aggregate principal amount outstanding under this Debenture (the
“Principal
      Amount”),
      together with all accrued interest thereon shall be made on the Maturity
      Date.

     

    ARTICLE
      II

    CONVERSION
      REPAYMENT 

     

    2.1.  Optional
      Conversion.
      Subject
      to the terms of this Article II, the Holder shall have the right, but not the
      obligation, at any time until the Maturity Date, or thereafter during an Event
      of Default and to convert all or any portion of the outstanding Principal Amount
      and/or accrued interest and fees due and payable into fully paid and
      nonassessable shares of the Common Stock at the Fixed Conversion Price. The
      shares of Common Stock to be issued upon such conversion are herein referred
      to
      as the “Conversion
      Shares.”
The
      “Fixed
      Conversion Price”
shall
      mean $4.00.

     

    
      
         

      

      
         

        
          

        

      

      
         

      

    

     

    2.2.  Conversion
      Limitation.
      Notwithstanding anything contained herein to the contrary, the Holder shall
      not
      be entitled to convert pursuant to the terms of this Debenture an amount that
      would be convertible into that number of Conversion Shares which would exceed
      the difference between the number of shares of Common Stock beneficially owned
      by such Holder or issuable upon exercise of the warrant and the option held
      by
      such Holder and 4.99% of the outstanding shares of Common Stock of Borrower.
      For
      the purposes of the immediately preceding sentence, beneficial ownership shall
      be determined in accordance with Section 13(d) of the Exchange Act and
      Regulation 13d-3 thereunder. The Conversion Shares limitation described in
      this
      Section 3.2 shall automatically become null and void without any notice to
      any
      Borrower upon the occurrence and during the continuance beyond any applicable
      grace period of an Event of Default, or upon 65 days prior notice to
      Borrower.

     

    2.3.  Mechanics
      of Holder’s Conversion.
      In the
      event that the Holder elects to convert this Debenture into Common Stock, the
      Holder shall give notice of such election by delivering an executed and
      completed notice of conversion (“Notice
      of Conversion”)
      to
      Borrower and such Notice of Conversion shall provide a breakdown in reasonable
      detail of the Principal Amount, accrued interest and fees that are being
      converted. On each Conversion Date (as hereinafter defined) and in accordance
      with its Notice of Conversion, the Holder shall make the appropriate reduction
      to the Principal Amount, accrued interest and fees as entered in its records
      and
      shall provide written notice thereof to the Borrower on the Conversion Date.
      Each date on which a Notice of Conversion is delivered or telecopied to Borrower
      in accordance with the provisions hereof shall be deemed a Conversion Date
      (the
“Conversion
      Date”).
      A
      form of Notice of Conversion to be employed by the Holder is annexed hereto
      as
Exhibit
      A.
      Pursuant to the terms of the Notice of Conversion, Borrower will issue
      instructions to the transfer agent accompanied by an opinion of counsel to
      Borrower of the Notice of Conversion and shall cause the transfer agent to
      transmit the certificates representing the Conversion Shares to the Holder
      by
      physical delivery or crediting the account of the Holder’s designated broker
      with the Depository Trust Corporation (“DTC”)
      through its Deposit Withdrawal Agent Commission (“DWAC”)
      system
      within three (3) business days after receipt by Borrower of the Notice of
      Conversion (the “Delivery
      Date”).
      In
      the case of the exercise of the conversion rights set forth herein the
      conversion privilege shall be deemed to have been exercised and the Conversion
      Shares issuable upon such conversion shall be deemed to have been issued upon
      the date of receipt by Borrower of the Notice of Conversion. The Holder shall
      be
      treated for all purposes as the record holder of such Common Stock, unless
      the
      Holder provides Borrower written instructions to the contrary.Late
      Payments.
      Each
      Borrower understands that a delay in the delivery of the shares of Common Stock
      in the form required pursuant to this Article beyond the Delivery Date could
      result in economic loss to the Holder. As compensation to the Holder for such
      loss, the each Borrower agrees to jointly and severally pay late payments to
      the
      Holder for late issuance of such shares in the form required pursuant to this
      Article II upon conversion of the Debenture, in the amount equal to $500 per
      business day after the Delivery Date. Each Borrower shall pay any payments
      incurred under this Section in immediately available funds upon demand.


     

    
      
         

      

      
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    2.4.  Conversion
      Mechanics.

     

    (a)  The
      number of shares of Common Stock to be issued upon each conversion of this
      Debenture shall be determined by dividing that portion of the principal and
      interest and fees to be converted, if any, by the then applicable Fixed
      Conversion Price. 

     

    (b)  The
      Fixed
      Conversion Price and number and kind of shares or other securities to be issued
      upon conversion shall be subject to adjustment from time to time upon the
      happening of certain events while this conversion right remains outstanding,
      as
      follows:

     

    A.  Reclassification,
      etc.
      If
      Borrower at any time shall, by reclassification or otherwise, change the Common
      Stock into the same or a different number of securities of any class or classes,
      this Debenture, as to the unpaid Principal Amount and accrued interest thereon,
      shall thereafter be deemed to evidence the right to purchase an adjusted number
      of such securities and kind of securities as would have been issuable as the
      result of such change with respect to the Common Stock (i) immediately prior
      to
      or (ii) immediately after such reclassification or other change at the sole
      election of the Holder.

     

    B.  Stock
      Splits, Combinations and Dividends.
      If the
      shares of Common Stock are subdivided or combined into a greater or smaller
      number of shares of Common Stock, or if a dividend is paid on the Common Stock
      or any preferred stock issued by Borrower in shares of Common Stock, the Fixed
      Conversion Price shall be proportionately reduced in case of subdivision of
      shares or stock dividend or proportionately increased in the case of combination
      of shares, in each such case by the ratio which the total number of shares
      of
      Common Stock outstanding immediately after such event bears to the total number
      of shares of Common Stock outstanding immediately prior to such
      event.

     

    2.5.  Reservation
      of Shares.
      During
      the period the conversion right exists, Borrower will reserve from its
      authorized and unissued Common Stock a sufficient number of shares to provide
      for the issuance of Common Stock upon the full conversion of this Debenture.
      Borrower represents that upon issuance, such shares will be duly and validly
      issued, fully paid and non-assessable. Borrower agrees that its issuance of
      this
      Debenture shall constitute full authority to its officers, agents, and transfer
      agents who are charged with the duty of executing and issuing stock certificates
      to execute and issue the necessary certificates for shares of Common Stock
      upon
      the conversion of this Debenture.

     

    2.6.  Registration
      Rights.
      The
      Holder has been granted registration rights with respect to the shares of Common
      Stock issuable upon conversion of this Debenture as more fully set forth in
      a
      Registration Rights Agreement dated as of the date hereof between Borrower
      and
      the Holder.

     

    
      
         

      

      
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    2.7.  Issuance
      of New Debenture.
      Upon
      any partial conversion of this Debenture, a new Debenture containing the same
      date and provisions of this Debenture shall, at the request of the Holder,
      be
      issued by the Borrower to the Holder for the principal balance of this Debenture
      and interest which shall not have been converted or paid. Subject to the
      provisions of Article III, the Borrower will pay no costs, fees or any other
      consideration to the Holder for the production and issuance of a new
      Debenture.

     

    ARTICLE
      III

    EVENTS
      OF DEFAULT

     

    The
      occurrence of any of the following events set forth in Sections 3.1 through
      3.9,
      inclusive, shall be an “Event
      of Default”:

     

    3.1.  Failure
      to Pay Principal, Interest or other Fees.
      Borrower fails to pay when due any installment of principal, interest or other
      fees hereon or on any other promissory note issued pursuant to the Purchase
      Agreement, and such failure shall continue for a period of ten (10) days
      following the date upon which any such payment was due.

     

    3.2.  Breach
      of Covenant.
      Borrower breaches any covenant or other term or condition of this Debenture
      in
      any material respect and such breach, if subject to cure, continues for a period
      of fifteen (15) days after the occurrence thereof.

     

    3.3.  Breach
      of Representations and Warranties.
      Any
      representation or warranty of Borrower made herein, or the Purchase Agreement,
      or in any Ancillary Agreement shall be false or misleading in any material
      respect.

     

    3.4.  Stop
      Trade.
      An SEC
      stop trade order or Principal Market trading suspension of the Common Stock
      shall be in effect for 5 consecutive days or 5 days during a period of 10
      consecutive days, excluding in all cases a suspension of all trading on a
      Principal Market, provided that Borrower shall not have been able to cure such
      trading suspension within 30 days of the notice thereof or list the Common
      Stock
      on another Principal Market within 60 days of such notice. The “Principal
      Market” for the Common Stock shall include the NASD OTC Bulletin Board, NASDAQ
      SmallCap Market, NASDAQ National Market System, American Stock Exchange, or
      New
      York Stock Exchange (whichever of the foregoing is at the time the principal
      trading exchange or market for the Common Stock), or any securities exchange
      or
      other securities market on which the Common Stock is then being listed or
      traded.

     

    3.5.  Receiver
      or Trustee.
      Any
      Borrower or any of its Subsidiaries shall make an assignment for the benefit
      of
      creditors, or apply for or consent to the appointment of a receiver or trustee
      for it or for a substantial part of its property or business; or such a receiver
      or trustee shall otherwise be appointed.

     

    
      
         

      

      
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    3.6.  Judgments.
      Any
      money judgment, writ or similar final process shall be entered or filed against
      any Borrower or any of its Subsidiaries or any of their respective property
      or
      other assets for more than $250,000 in the aggregate for Borrower, and shall
      remain unvacated, unbonded or unstayed for a period of thirty (30)
      days.

     

    3.7.  Bankruptcy.
      Bankruptcy, insolvency, reorganization or liquidation proceedings or other
      proceedings or relief under any bankruptcy law or any law for the relief of
      debtors shall be instituted by or against any Borrower or any of its
      Subsidiaries.

     

    3.8.  Default
      Under Other Agreements.
      The
      occurrence of an Event of Default under and as defined in the Purchase Agreement
      or any Ancillary Agreement or any event of default (or similar term) under
      any
      other agreement evidencing indebtedness of at least $500,000.

     

    3.9.  Failure
      to Deliver Common Stock or Replacement Debenture.
      Borrower’s failure to timely deliver Common Stock to the Holder pursuant to and
      in the form required by this Debenture and the Purchase Agreement, if such
      failure to timely deliver Common Stock shall not be cured within five (5) days.
      If Borrower is required to issue a replacement Debenture to Holder and Borrower
      shall fail to deliver such replacement Debenture within seven (7) Business
      Days.

     

    DEFAULT
      RELATED PROVISIONS

     

    3.10.  Default
      Interest Rate.
      Following the occurrence and during the continuance of an Event of Default,
      interest on this Debenture shall automatically be increased by one-half percent
      (0.50%) per month, and all outstanding Obligations, including unpaid interest,
      shall continue to accrue interest from the date of such Event of Default at
      such
      interest rate applicable to such Obligations until such Event of Default is
      cured or waived.

     

    3.11.  Conversion
      Privileges.
      The
      conversion privileges set forth in Article II shall remain in full force and
      effect immediately from the date hereof and until this Debenture is paid in
      full.

     

    3.12.  Cumulative
      Remedies.
      The
      remedies under this Debenture shall be cumulative.

     

    ARTICLE
      IV

    DEFAULT
      PAYMENTS

     

    4.1.  Default
      Payment.
      If an
      Event of Default occurs and is continuing beyond any applicable grace period,
      the Holder, at its option, may elect, in addition to all rights and remedies
      of
      Holder under the Purchase Agreement and the Ancillary Agreements and all
      obligations of each Borrower under the Purchase Agreement and the Ancillary
      Agreements, to require the Borrowers to make a Default Payment (“Default
      Payment”).
      The
      Default Payment shall be 105% of the outstanding principal amount of the
      Debenture, plus accrued but unpaid interest, all other fees then remaining
      unpaid, and all other amounts payable hereunder. The Default Payment shall
      be
      applied first to any fees due and payable to Holder pursuant to the Debentures
      or the Ancillary Agreements, then to accrued and unpaid interest due on the
      Debentures and then to outstanding principal balance of the
      Debentures.

     

    
      
         

      

      
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    4.2.  Default
      Payment Date.
      The
      Default Payment shall be due and payable immediately on the date that the Holder
      has exercised its rights pursuant to Section 4.1 (“Default
      Payment Date”).

     

    ARTICLE
      V

    MISCELLANEOUS

     

    5.1.  Failure
      or Indulgence Not Waiver.
      No
      failure or delay on the part of the Holder hereof in the exercise of any power,
      right or privilege hereunder shall operate as a waiver thereof, nor shall any
      single or partial exercise of any such power, right or privilege preclude other
      or further exercise thereof or of any other right, power or privilege. All
      rights and remedies existing hereunder are cumulative to, and not exclusive
      of,
      any rights or remedies otherwise available.

     

    5.2.  Notices.
      Any
      notice herein required or permitted to be given shall be in writing and provided
      in accordance with the terms of the Purchase Agreement.

     

    5.3.  Amendment
      Provision.
      The
      term “Debenture”
and
      all
      reference thereto, as used throughout this instrument, shall mean this
      instrument as originally executed, or if later amended or supplemented, then
      as
      so amended or supplemented, and any successor instrument as it may be amended
      or
      supplemented.

     

    5.4.  Assignability.
      This
      Debenture shall be binding upon each Borrower and its successors and assigns,
      and shall inure to the benefit of the Holder and its successors and assigns,
      and
      may be assigned by the Holder in accordance with the requirements of the
      Purchase Agreement.

     

    5.5.  Cost
      of Collection.
      If
      default is made in the payment of this Debenture, each Borrower shall jointly
      and severally pay the Holder hereof reasonable costs of collection, including
      reasonable attorneys’ fees.

     

    5.6.  Governing
      Law; Consent to Jurisdiction; Waiver of Jury Trial.
      This
      Debenture shall be governed by, and construed in accordance with, the internal
      laws of the State of Nevada without regard to the choice of law principles
      thereof. Each of the parties hereto irrevocably submits to the exclusive
      jurisdiction of the courts of the State of Nevada and the United States District
      Courts situated therein for the purpose of any suit, action, proceeding or
      judgment relating to or arising out of this Agreement and the transactions
      contemplated hereby. Service of process in connection with any such suit, action
      or proceeding may be served on each party hereto anywhere in the world by the
      same methods as are specified for the giving of notices under this Agreement.
      Each of the parties hereto irrevocably consents to the jurisdiction of any
      such
      court in any such suit, action or proceeding and to the laying of venue in
      such
      court. Each party hereto irrevocably waives any objection to the laying of
      venue
      of any such suit, action or proceeding brought in such courts and irrevocably
      waives any claim that any such suit, action or proceeding brought in any such
      court has been brought in an inconvenient forum. EACH
      OF THE PARTIES HERETO WAIVES ANY RIGHT TO REQUEST A TRIAL BY JURY IN ANY
      LITIGATION WITH RESPECT TO THIS AGREEMENT AND REPRESENTS THAT COUNSEL HAS BEEN
      CONSULTED SPECIFICALLY AS TO THIS WAIVER.

     

    
      
         

      

      
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    5.7.  Maximum
      Payments.
      Nothing
      contained herein shall be deemed to establish or require the payment of a rate
      of interest or other charges in excess of the maximum permitted by applicable
      law. In the event that the rate of interest required to be paid or other charges
      hereunder exceed the maximum permitted by such law, any payments in excess
      of
      such maximum shall be credited against amounts owed by Borrowers to the Holder
      and thus refunded to the Borrowers

     

    5.8.  Construction.
      Each
      party acknowledges that its legal counsel participated in the preparation of
      this Debenture and, therefore, stipulates that the rule of construction that
      ambiguities are to be resolved against the drafting party shall not be applied
      in the interpretation of this Debenture to favor any party against the
      other.

     

    [Balance
      of page intentionally left blank; signature page follows.]

     

     

    
      
         

      

      
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    IN
      WITNESS WHEREOF,
      Borrower has caused this Convertible Debenture to be signed in its name
      effective as of this 23rd day of January, 2006.

     

    
      	 	 	 
	 	TRIANGLE
              PETROLEUM CORPORATION
	 	 
	 	 
	 	By: /s/
              MARK GUSTAFSON
	 	Name: Mark Gustafson
	 	
              Title:
                President

            


    

     

     

    
      
         

      

      
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