Description and Geology

In 2011, oil was discovered at Surprise 1 within the Ordovician Lower Stairway Sandstone at a depth of 2,500 metres.  This discovery extends the Horn Valley Siltstone hydrocarbon fairway ~160 km west of the Mereenie Oil and Gas Field. Surprise is a doubly plunging, anticlinal trap situated on one of many northwest trends.  The trap formed as the result of compression and associated salt tectonism in the underlying Neoproterozoic section.  The Lower Stairway Sandstone is also productive at the Palm Valley Gas Field where the gas is primarily produced from natural fractures.