Perth Basin oil and gas exploration company Norwest Energy has provided an update further to recent completion of wireline logging operations at the Lockyer Deep-1 conventional gas discovery well.
The EP368 Joint Venture's petrophysical analysis of the Kingia Fm. confirms a 34 metre (TVD) gross pay interval at the top of the Kingia Sandstone, between 3,888 metres and 3,922 metres (TVDSS), with gas interpreted down to low permeability or tight rock (i.e. no gas water contact). Based on an 8% porosity cutoff, net gas pay within this interval is 20.2 metres (TVD), predominantly within the upper section. This net pay zone is of exceptional quality, with average porosity of 16% and average permeability estimated at 500 Millidarcies. The maximum measured porosity is 28%.
Reservoir pressure at the top of the pay interval is 6,514 psi. A well-defined gas gradient was measured through the pay interval which, combined with the regional water gradient, indicates the presence of an up to 800 metre gas column (from the North Erregulla crestal location) down to a Free Water Line at approx. 4,500 metres (TVDSS, Refer Figure 2). Norwest Energy regards this as remarkable as it confirms the fault-seal integrity of the structure's main bounding faults, regardless of orientation and despite a very significant gas column. This result substantially upgrades the additional prospectivity identified within EP368 and EP426, including Lead D (20 km2) directly to the northeast.
Based on a gas column of up to 800 metres the indicative areal extent of the discovery is approximately 66 km2, with an additional 22 km2 of low-risk upside in the downthrown fault block to the south of the North Erregulla culmination (refer Figure 1). The associated preliminary estimate of gas resources within the Kingia 66 km2 area alone is believed to exceed the Company's pre-drill High Case prospective resources for the Kingia and High Cliff combined (refer ASX Announcement of 28 October 2019). The remaining 13.8 metres within the gross Kingia pay interval includes sandstones with porosity less than the 8% cutoff. While these sandstones are not regarded as conventional pay, the Company believes they may well provide incremental recoverable gas resources through secondary charge of the overlying high quality pay zone. Further study is required in this regard.
Norwest Energy Managing Director, Iain Smith commented, 'The Lockyer Deep-1 discovery is an extraordinary outcome for Norwest Energy. The upper Kingia pay interval is arguably the highest quality reservoir encountered thus far within the deep Permian gas play of the north Perth Basin, and this fact combined with an inferred significant gas column gives us good reason to believe that the structure hosts gas resources that are greater than our pre-drill High Case prospective resource. Such an outcome happens only very rarely in our industry, and we now look forward to production testing of what we expect to be a very high deliverability reservoir.'