Envoi has been engaged by Australian based Advent Energy Limited to identify a new partner to join their majority (85%) operated JV with Bounty Oil & Gas (15%), to explore their highly prospective but unexplored PEP11 Block offshore Sydney Basin, NSW. This large, 4,578 km2 Licence covers the most prospective offshore part of Sydney Basin in which palaeogeographic and depositional modelling of the Permo-Triassic play (already proven onshore by historical drilling in the near shore facies) is interpreted to thicken basin-ward offshore into a more distal facies. Here the play remains totally untested, despite clear evidence of very large 2D defined closures being associated with active hydrocarbon system seepage. All of which lies right on the door step of the gas strapped eastern Australia energy markets.
Advent’s geophysical work now shows multiple large prospects coincident with seismic anomalies including AVOs, gas chimneys, reverse polarity events and flat spots across their acreage. The active hydrocarbon system offshore is supported by satellite seepage and thermogenic gas bubbling from the seabed. Large pock marks evident on the sea floor is also further evidence of gas migration which correlates strongly to the sub-surface structures mapped in PEP11.
Advent originally farmed into the Licence operated by Bounty and drilled the New Seaclem-1 well in 2010 which fulfilled the previous work obligations. This well, which was the first ever exploration well drilled offshore, ended up targeting a shallow seismic anomaly in the Tertiary in the north of the block. The original location, targeting the deeper Permo-Triassic play prospects, was abandoned after the site survey required prior to drilling, failed to confirm seabed stability and mitigate the risks posed by shallow gas for use of the rig contracted. Although the New Seaclem-1 well failed to find hydrocarbons, it proved thick high-quality reservoir sands in the Tertiary and sufficient thermal maturity for a Permian source in the Newcastle Syncline.
Extensive reinterpretation of the existing 3,805 km 2D seismic has since defined a total 14 prospective leads in the deeper undrilled play in PEP11 with a combined estimated prospective recoverable (Pmean) resource potential in excess of 5.7 Tcf. The Permo-Triassic targets in just the two largest closures are estimated capable of a combined 2.5+ Tcf (P50) recoverable resource, trapped in four-way dip and fault closed structures, with stratigraphic upside, sourced by early Permian shales and coals, in the mature offshore source kitchen.
PEP11’s proximity to the extensive East Coast gas infrastructure, with pipeline tie-in only 25 km away at its nearest point, would allow immediate access to the major gas markets of eastern Australia.
Advent is already committed to fund an initial seismic / seabed survey in 2018, estimated likely to cost A$ 0.7 million, which would fulfill the current Licence commitment and to secure the Licence to 2021, and for which Regulatory and Environmental Planning approvals are in place. Advent is offering a material interest in PEP11 to an incoming party in return for a commitment to fund i). the acquisition of a modern 500+ km2 3D seismic survey (Est. cost A$ 5 million), which would fulfill the forward Licence commitment and more accurately resolve the deeper Permo-Triassic play to define locations on the best prospects, and/or ii). drill a subsequent well in 2019 (Est. cost A$ 20 million).