The Arafura Basin, despite its thick sedimentary succession and shallow waters depths, is largely a frontier region. Previous exploration in the region has been limited to the Goulburn Graben, where the thick sedimentary succession and large inversion structures provided the exploration targets. Drilling activity occurred in 3 phases - the early 1970s, early 1980s and the late 1980s to early 1990s. To date, a total of nine wells has been drilled, with the best result being an oil and gas show at Arafura-1. This exploration also confirmed the presence of essential petroleum system elements including potential Palaeozoic and Mesozoic source and reservoir rocks and a thick regional seal in the overlying Money Shoal Basin sediments.

The lack of commercial success has been attributed to a combination of poor quality reservoirs in the Palaeozoic and/or restricted fluid movement, hydrocarbon charge, timing of events and breach of structure. However, despite the current lack of success, there are numerous indicators for untested petroleum potential, particularly in the undrilled northern region of the basin:

• The petroleum systems elements found in the Goulburn Graben are also likely to be present in the northern region.
• Many of the risks identified in the Goulburn Graben are reduced in the northern region (shallower reservoirs, reduced charge risk and reduced risk of breached structures).
• A wide range of play types are present, ranging from faulted anticlines and sub-unconformity plays in Palaeozoic strata to fault block plays and numerous stratigraphic plays in Mesozoic strata.
• Direct evidence that hydrocarbon generation and expulsion has occurred in the Arafura Basin is provided by oil shows/indications and gas indications in the majority of wells drilled, and the presence of interstitial solid bitumens in many samples. Seismic data show bright amplitudes at various stratigraphic levels and these may indicate hydrocarbons in the section.
• A recent survey to investigate potential hydrocarbon seepage in the Arafura Basin collected a range of datasets, including sub-bottom profiles, side-scan sonar and echosounder data. These, together with available deep-seismic data, show a range of features that are indicative of the presence of hydrocarbons in the northern and northeastern basin (For further information on the survey results please click here).