Description and Geology

The northern margin of the Amadeus Basin forms a broad northward dipping monocline, terminated at the northern margin by south verging thrust faults. Multiple northwest plunging anticlinal trends lie within the permit, along each of which hydrocarbons may be trapped in structural culminations formed by faults, dip reversal, or the presence of salt movement such as that underlying Surprise Oil Field. Stratigraphic traps may also be present. The proven Larapintine petroleum system comprises reservoirs of the Pacoota Sandstone and Stairway Sandstone sealed by the Stokes Siltstone, and charged by hydrocarbons generated and expelled from the Horn Valley Siltstone (HVS). The HVS is oil mature to the west, and continues eastwards and progressively gas mature for 240 km within the permit. Underlying these are Cambrian and Neoproterozoic rocks with potential demonstrated at the Dingo Gas Field where the Arumbera Sandstone is productive.