Surprise Oil Field

Tenement Information

map surprise oil field

The Surprise oil field was the first production licence offered in onshore Northern Territory since the passing of the Native Titles Act 1993 which was an important event not only for Central but also for the Northern Territory and the Traditional Owners of the land.

Tenement Area
Location Operator CTP Consolidation Entity Other JV Participants
L 6 929 Amadeus Basin NT Central 100 100


Facility Details

A permanent production facility came on line in October 2014 at the end of an extended production test of the Surprise 1 well. This comprises of wellhead pumping equipment, a heater treater, oil storage, water handling and evaporation pond.  In March 2014 a small temporary test production and storage facility was installed that allowed production to commence. The temporary test facility was dismantled and some of the larger components incorporated into the permanent facility.

Low oil prices and the remoteness of the field led to the decision to temporarily shut-in oil production from August 2015. The facilities have been mothballed to preserve the equipment for later service.

Description and Geology

In 2011 oil was discovered at Surprise within the Ordovician lower Stairway Sandstone at a depth of 2,500 metres sub-surface.  This discovery extends the Horn Valley Siltstone hydrocarbon fairway 160 km west of the Mereenie Oil and Gas Field. Surprise is an anticlinal trap situated on one of many northwest plunging trend.  The trap formed as the result of compression and associated salt tectonism in the underlying Neoproterozoic section.


The Surprise Oil Field is a single-well development producing oil into a small tank farm located on the site. The production process involves pumping fluid to surface where it is separated into its oil, water and gas components before storage and trucking of the oil.

The field commenced production in March 2014, producing approximately 87,000 barrels of oil to 30 June 2015.  Production averaged 85 bopd in mid-2015.

Low oil prices and the remoteness of the field led to the decision to temporarily shut-in oil production from August 2015.  Production could re-commence if oil prices recover significantly in $A terms and the well has displayed good re-charge.

Appraisal and Development

Following discovery of the oil field on 2D seismic data, in 2012 Central acquired 3D seismic data to better define the structure. This has been successful in proving the existence of an undrilled eastern culmination referred to as Surprise East.


The licence area of 929 km2 provides scope for additional prospects geologically akin to Surprise, on the intersection of regional northwest trending hinge lines with faults or salt bodies. The recent acquisition of gravity data is assisting the location and delineation of targets for additional seismic. Other targets include oil or gas in the underlying Cambrian to Neoproterozoic section where larger faults and salt bodies create various trap types.