VIC/P57, Gippsland Basin
Gippsland Basin Activities
3D Oil Limited was granted the VIC/P57 Exploration Permit, located in the north-west offshore Gippsland Basin, in April 2004. After renewing the permit in 2011 for a further 6 years and farmout activities 3D Oil currently holds 24.9% of VIC/P57. The initial six-year permit term expired in July 2011 and, following the required relinquishment of some of the original acreage, the permit has been renewed for another five years, commencing August 2011. The renewed permit area is as shown in the figure below.
Gippsland Basin Overview
Historically the Gippsland Basin has been the most prolific petroleum liquids province in Australia. It accounts for approximately 57 percent of Australia’s produced petroleum liquids. To date, almost29000 PJ (4.8 billion barrels) of petroleum liquids and 17000 PJ of gas have been discovered from the more than 150 exploration wells drilled in the offshore Gippsland Basin, making it significant by world standards and achieving a technical success rate better than 40 percent.
Since its renewal in August 2011 and the grant of VIC/L31over the West Seahorse Field in December 2013, VIC/P57 is approximately 449 square kilometres in size, covering a geologically diverse area of the Northern Terrace and the Central Deep areas of the offshore Gippsland Basin.
VIC/P57 is flanked to the south by several oil and gas fields including the giant Barracouta and Snapper gas fields. These are located on a large regional anticline, which is interpreted to shield the VIC/P57 region from significant gas charge. Consequently it is thought unlikely that any oil accumulations in VIC/P57 will have been displaced by gas. Other oil and gas fields on the southern flank of the permit include Golden Beach, Mulloway/Whiptail, Seahorse, Wirrah, Whiting, Emperor and Sweetlips. In recent years exploration wells along trend of prospects and leads in VIC/P57 have intersected hydrocarbons, VIC/P57 including West Whiptail-1, Longtom-2, Grayling-1A, West Moonfish-1, North Wirrah-1 and South East Remora-1. Within VIC/P57, the 2008 Wardie-1 exploration well also encountered oil shows. All of these targets were located from mapping of Esso’s Northern Margin 3D seismic survey.
VIC/P57 Work Programme
The approved minimum work programme for the five-year renewal period is as shown below.
|Year of Term of Permit||Permit Year Starts||Permit Year Ends||Minimum Work Requirements||Estimated Expenditure Constant dollars (indicative only) $A|
|1||10/08/2011||9/08/2012||500km2 Interpretation and depth conversion of re-processed Northern fields seismic data||300,000|
|2||10/08/2012||9/08/2013||Geological and Geophysical Studies Pre-drill prepatory works, including site investigation studies||600,000|
|3||10/08/2013||9/08/2015||1 exploration well||18,000,000|
|4||10/08/2015||9/08/2016||Geological and Geophysical studies||400,000|
|5||10/08/2016||9/08/2017||1 exploration well||18,000,000|
Despite its proximity to numerous hydrocarbon discoveries, the VIC/P57 permit is lightly drilled, originally only containing four wells in and close to the West Seahorse field. The West Seahorse field was excised from VIC/P57 as VIC/L31 in December 2013 and in November 2014 3D Oil monetized it’s interest in VIC/L31 and no longer holds any interest in that permit.
VIC/P57 contains several prospects and leads. Extensive interpretation of the Northern Fields 3D seismic survey and new data post-drilling has been incorporated into 3D Oil’s permit-wide mapping of the prospects and leads, resulting in improved confidence in the depth maps, particularly of the upper Latrobe Group section. Extensive reprocessing of the Northern Fields 3D seismic data and ongoing evaluation of the Golden Beach and Emperor Subgroups has resulted in improved understanding of the distribution of these fairways across the permit and better definition of the new leads within these strata.
The Felix Prospect is located between the Moonfish/West Moonfish and Wirrah fields, with closure mapped at multiple levels from the intra-Latrobe into the Golden Beach Subgroup. Both Moonfish and Wirrah have multiple levels of trapped hydrocarbons, and Felix is also predicted to contain stacked hydrocarbon columns. The recoverable volume range is about 15-80 MMstb, depending on the number of successful levels.
Sea Lion is located to the west of the West Seahorse oil field, on an extension of the oil fairway. It is a simple structural closure against the Rosedale Fault with the potential for oil at multiple levels. This play type has historically had a very high success rate in the Gippsland Basin. The most likely recoverable volume is assessed as around 20 MMstb, but there is potential for greater volumes if hydrocarbons are confirmed at multiple levels.
Golden Beach and Emperor Subgroup Leads
The Golden Beach and Emperor Subgroup plays include the Lucifier, Dexter and Kangafish leads, which are low-side, fault-dependent structures associated with the Emperor fault along the basin’s northern margin. The leads are of similar trapping styles, and on trend with other northern margin discoveries to the east, such as the Longtom, Remora, Sunfish and Kipper fields. These play types also have the potential to occur beneath some of the upper and intra-Latrobe Group prospects and leads, such as Felix and Sea Lion, which may result in the possibility of evaluating them in the same exploration well as a shallower target.
The Salsa lead, to the north east, is a top of Latrobe Group closure and provides attractive follow-up potential to a success at Sea Lion. It straddles the edge of the existing 3D seismic data, but has the potential to be of significant size.
The Scooter lead is another top of Latrobe Group closure, in this case on a migration spill chain out of the Emperor and Sweetlips discoveries,. The feature is primarily erosional, created by the Marlin Channel. Both Emperor and Sweetlips have oil legs in the upper Latrobe Group, and are close to their spill points.