K/B
Your calc assumes gas @ $0.4/GJ
Bears checking....I use $1.79/GJ which was the Arrow buys Bow merger/t-over price. But this is for 2P reserves. My records have an average of $0.74 per GJ paid for 3P reserves.
I guess we have to wait till SXY writes its gas resources which has been stated as happening in June this year.