EP413 – Arrowsmith Oil Discovery
|JV Participant||Percentage Interest|
|Norwest Energy NL (Operator)||27.945%|
|Mitsui & Co., Ltd||44.252%|
|Bharat PetroResources Limited||27.803%|
In 2015, Norwest successfully completed the EP413 Arrowsmith 3D seismic acquisition survey on behalf of the EP413 Joint Venture. The survey was designed to assess the extent of the resource surrounding Arrowsmith-2. The processing of the 3D dataset was completed, including pre-stack depth migration and fracture analysis. Final results indicate a substantial improvement in structural definition, providing a greatly improved understanding of the geology within the permit boundaries, and with confirmation that the geology supports ongoing development plans for the permit, which covers an area of 508.3km².
Work is currently on hold due to WA state government technical inquiry into hydraulic fracture simulation. In November 2018, the Western Australian state government released the report on the scientific inquiry into hydraulic fracture stimulation, along with its response to the report. The moratorium was subsequently lifted, and the government response included a statement that there are a range of regulatory reforms to be developed and implemented, and until finalised, it will not be possible to carry out any hydraulic fracture stimulation programs.
The main formations of interest from the Arrowsmith-2 testing are present throughout the survey area, with the fracture analysis indicating an increased presence of natural fractures to the southern end of the block (Carynginia Formation), meaning increased natural gas flow is likely from this area. An unexpected outcome from the 3D seismic survey was the discovery of additional prospectivity in the southern end of the permit, named the Brand Prospect. This area is approximately 7.5km south of Arrowsmith-2 on the north-plunging Permian anticline, located on the Arrowsmith-Woodada Permian Terrace. This prospect targets tight gas in the Kockatea, Beekeeper, Carynginia, Irwin River Coal Measures and High Cliff Sandstone, with conventional gas possible from the naturally fractured Carynginia. On the basis of similarities in structural form and seismic character with that seen further south over the Woodada Gas Field, there is also the potential for stratigraphically trapped conventional gas.
EP413 Brand Prospect
This new prospectivity in no way detracts from the reported shale gas potential of the permit, particularly as the shale formations are continuous throughout the block, however it presents itself as an additional opportunity to evaluate, particularly with reference to planning the optimal surface location for a well. As this is a new prospect within the permit, the Joint Venture is carefully evaluating this information, and will complete a detailed review and interpretation of the entire 3D seismic survey area to determine the best location for the upcoming well.
EP413 Hydrocarbon Plays – Summary
|Carynginia (Beekeeper) Formation
Irwin River Coal Measures
High Cliff Sandstone
|Conventional Gas||Porous / fractured Permian formations
Fractured Carynginia / Beekeeper
Dolarenitic sands within the Beekeeper
|Tight Gas / Conventional Gas||Fractured lower Kockatea Shale|
Further work this year will fully assess the options for this highly prospective permit. A detailed in-house interpretation is now underway, and an EP413 Joint Venture meeting is planned for early February to finalise the work program for the year.