how $43.7 million becomes $18.25 million

I have traded NGE at various times and am not a holder now.However I read their announcements to find out how the drilling rig is coming on.I was interested to read today
"Using the 25 July 2013 exchange rate of AUD/USD 0.9149, the likely effect of this transaction is to increase the Company’s net assets by $18.25 million. A more detailed description of the impact on the Company’s finances is provided as an Appendix to this announcement"
It seems that $25 million is being used to write down the Exploration and Evaluation Account from $70 million to $45 million.I could understand it if they were repaying a loan but exploration and evaluation is usually a spent figure and not a loan.It looks like I will have to go and read NGE's Annual Report and Accounts to find out what lurks in the Exploration and Evaluation Account.