August 9, 2007 Samson Oil & Gas USA, Inc

Exhibit 4.5

August 9, 2007

Samson Oil & Gas USA, Inc

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Samson Oil & Gas Limited

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Perth WA 6000

Syndicated Convertible Loan Facility Agreement between Samson Oil & Gas USA, Inc. (“Samson”) and Macquarie Bank Limited (“MBL”) dated 26 May 2006 (“Credit Agreement”)

Dear Sirs

The Credit Agreement at Section 9.2 provides for the delivery of Reserve Reports.

MBL waives the requirement to deliver the Reserve Report with an effective date of 30 June 2007.

MBL and Borrower and Parent agree that the Reserve Report with an effective date of 31 March 2008 shall be prepared by an Independent Engineering Consultant.

MBL and Borrower and Parent agree that the Reserve Report with an effective date of 30 June 2008 shall be prepared by the Parent.

Save for the above changes the provisions of clause 9.2 shall continue to apply unamended.

MBL and Borrower and Parent agree that clause 9.23(b) of the Credit Agreement is deleted.

MBL and Borrower and Parent agree that clause 9.23(e) of the Credit Agreement is amended by replacing “1:1” with “1.2:1”.

Capitalized terms used in this letter have, unless otherwise defined in this letter, the same meaning as described in the Credit Agreement.

Please acknowledge your acceptance of these matters by signing below and returning this letter to sender. Should you have any questions about the information provided please feel free to contact ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇ at ▇▇▇ ▇ ▇▇▇▇ ▇▇▇▇.

Yours faithfully

/s/ Vanessa Lentall /s/ ▇▇▇▇ ▇▇▇▇▇▇▇

▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇ Division Director Metals and Energy Capital Division ▇▇▇▇ ▇▇▇▇▇▇▇ Division Director Legal Risk Management Division

Acknowledged this 6th day of September, 2007

/s/ ▇▇▇▇▇ ▇▇▇▇▇▇                                         

▇▇▇▇▇▇ Oil & Gas USA, Inc

/s/ ▇▇▇▇▇ ▇▇▇▇▇▇                                         

▇▇▇▇▇▇ Oil & Gas Limited