Otway Basin gas discovery
Beach Energy discovers gas field near Penola.
The discovery well, Haselgrove 3 ST1, is located on state forestry land 8 km south of Penola in Petroleum Production Licence 62. The deviated well reached a total depth of 4,331 m. Primary targets were the Otway Basin Early Cretaceous Sawpit Sandstone and Pretty Hill Sandstone.
On 11 January 2018 Beach reported that flow test results from Sawpit Sandstone indicate a high deliverability reservoir, which provides encouragement to commercialise what could be a potentially large gas resource.
The well intersected an estimated gross gas column of 104 m (all hydrocarbon column data is expressed as total vertical thickness) in the Sawpit Sandstone, with estimated net pay of 25.6 m. An estimated gross gas column of 11.6 m was also intersected in the shallower Pretty Hill Sandstone, with estimated net pay of 8.5 m.
Initial testing of the Sawpit Sandstone enabled preliminary assessment of well deliverability and gas composition. A cased hole test over the interval 4,023–4,185 m flowed gas at a rate of 25 million standard cubic feet per day (MMscfd) sustained over 100 minutes through a 36/64 inch choke and at 2,700 pounds per square inch gauge well head pressure. Flow rates were constrained to 25 MMscfd due to the size of completion tubing (2 7/8 inch). Early indications suggest the Sawpit Sandstone could flow at rates greater than 25 MMscfd. Preliminary gas sample analysis indicates low inert content, which should minimise gas processing requirements.
Haselgrove 3 ST1 is currently shut-in with preparations underway for commencement of an initial production test in early February to confirm well deliverability and gas composition and assist field development planning. Results will be integrated with other subsurface data to estimate the size of the gas resource.
– Elinor Alexander