Advent Spies Zones Analogous to Marlim in Offshore Sydney Basin

MEC Resources advised that its investee company Advent Energy has interpreted significant new prospective multi-Tcf stratigraphic plays in an ongoing review of its exploration data for the PEP11 offshore Sydney Basin project (JV partner -- Bounty Oil & Gas NL).

Advent has previously reported the prospective P10 unrisked gas resource estimate of 16.3 trillion cubic feet for the permit, as residing in deeper, structural Permo-Triassic targets associated with the Offshore Uplift.

PEP11 covers a very large area (over 8,100km2). In addition to the aforementioned prospects, further examination of features in the Cainozoic sediment wedge overlying the Permo-Triassic sediments along the Sydney Basin continental shelf has demonstrated "soft" high amplitude anomalies (reverse polarity to the water bottom reflector) that are observed along sequential seismic lines continuously over considerable (>60 km) lateral NE-SW extent.

Advent notes that these newly identified prospective zones are analogous to the giant Marlim field in the Campos Basin in Brazil.

Location (left) and seismic transect (below) of the Marlim Oil Field, Campos Basin, Brazil, as used by Essential Petroleum as an analogy to their Descartes Prospect, in VIC/P50 in the offshore Otway Basin, Victoria. Essential Petroleum state that this prospect may hold 800 MMbbl oil (P50).

Modelling suggests that the hydrocarbon migration in the offshore Sydney Basin in PEP11, as described previously by Advent as manifesting in the seismic data as HRDZs, gas chimneys, chemotropic mounds and similar features, has charged the sediments of the Cainozoic wedge.

The Quaternary sediments have been described to comprise a large variation in grainsize (from clay to gravel) with the dominant grain size a medium-to coarse grained sand (Sayers, 2004). It is feasible that an appropriate sorting of sediments during the progradational Cainozoic deposition resulted in an ideal package of potential reservoir and sealing units -- Boyd (1998) describes similar such "forced regressive shorelines" as of considerable importance to the hydrocarbon exploration industry because of the significant potential for good reservoir development. In addition, no faults have been interpreted in the Cainozoic sediment wedge on seismic data from modern surveys, implying very low risk from a 'fault breach' point of view (Sayers, 2004).

In a further step towards commercial development of the project, conceptual well design and well testing planning has been completed for drilling of the Fish Prospect. Environmental approvals are in the process of being lodged. Advent is also continuing to pursue joint venture discussions and is in discussions to secure an appropriate drilling rig to test PEP11.