The reserve upgrade, which was independently certified by MHA Petroleum Consultants, also increased gas reserves in the 3P category (possible) about 20% to 1389PJ.
Metgasco said the joint venture was continuing its technical testing and evaluation program, aimed at providing further reserve upgrades over the coming months.
The Stratheden JV area is located in Clarence-Moreton Basin permit PEL 16 in New South Wales.
Metgasco holds 85% of the area, while CS Energy has the remaining 15%.