Australian oil and gas company Santos has made a 'significant' oil discovery at Pavo-1 exploration well, 46 kilometers east of the Dorado field in the Bedout Sub-basin, offshore Western Australia.
According to Santos, the well was drilled on the northern culmination of the greater Pavo structure and encountered a 60-meter gross hydrocarbon column in the primary Caley member reservoir target. Wireline data has confirmed 46 meters of net oil pay, with an oil-water contact intersected at 3,004 meters measured depth (MD), Santos said.
"Excellent reservoir quality is interpreted from logs with 19 percent average porosity, permeabilities in the 100 to 1,000 millidarcy range and hydrocarbon saturations averaging 80 percent, similar to that encountered in the Dorado field," the company said. The Dorado is one of the largest offshore oil discoveries on Australia's North Western Shelf, and Santos is working to develop it using an FPSO and a wellhead platform.
"Wireline logging operations to collect pressure, sample and rock data across the target Caley reservoir to inform resource volume estimates have been completed. Initial indications from rig site analysis are of a light sweet oil (~52 degrees API) with a low gas-oil ratio," Santos said of the Pavo discovery.
A 2C contingent resource for the northern culmination is assessed at 43 million barrels of oil (mmbbl) gross (Santos 70 percent interest 30 mmbbl). Santos is the operator with 70 percent stake. Carnarvon Energy holds the remaining 30 percent.
"The result at Pavo-1 also significantly de-risks the hydrocarbon-bearing potential of the separate southern culmination of the greater Pavo structure. The southern culmination has an additional best estimate P50 prospective resource of 40 mmbbl gross (Santos 70 percent interest 28 mmbbl). Probability of geologic success for the prospective resource in the southern culmination is assessed at 60 percent," Santos said.
Tie-back to Dorado
Santos Managing Director and Chief Executive Officer Kevin Gallagher described the Pavo discovery as a great result that could add further material value to the Dorado project through a potential low-cost tie-back to the proposed Dorado facility.
"The Pavo-1 success is expected to support a potential low-cost tie-back to the first phase of the proposed Dorado development, with Pavo north having an estimated breakeven cost of less than US$10 per barrel, and future gas production from the Bedout basin providing a source of supply into our existing domestic gas infrastructure in Western Australia,” Gallagher said.
“With the global oil and gas markets seeing increased volatility, low-CO2 oil and gas resources at Dorado and Pavo add significantly to Australia’s national energy security.
“It is also very encouraging for the next exploration well in the current campaign, Apus-1, which offers another potential nearby low-cost tie-in opportunity to the Dorado development.
“The Pavo-1 well result also proves the petroleum system in the basin is effective over a greater area, de-risking a number of nearby low-cost opportunities.”
The Pavo-1 well is being drilled using the jack-up drilling rig, Noble Tom Prosser, in a water depth of approximately 88 meters and is currently drilling ahead to the final planned total depth of approximately 4,200 metres MD.
The deepening of the well is focused on Early Triassic and Upper Permian stratigraphy not previously drilled in the basin and will provide key information to de-risk a significant number of gas and oil prospects in the Bedout Sub-basin, Santos said.
Once wireline logging operations are completed at final total depth, the well will be plugged and permanently decommissioned as planned, and the rig will move to the Apus-1 well location 20 kilometers south-west of the Pavo-1 well location.
Pavo-1 is located in petroleum permit WA-438-P. It is approximately 160 kilometers north-northeast of Port Hedland.
Dorado facilities in-place by 2025 end
Subject to the joint venture making a final investment decision (FID) this year, the Dorado production infrastructure is planned to be in-place by the end of 2025 and will have the capacity to tie-in other fields like Pavo with no material increase in operational costs. Pavo proves the extension of a working petroleum system some 46 kilometers east of Dorado. The well demonstrates that quality reservoir and trapping mechanisms are effective in this area, which hosts a suite of other exploration targets. These will now warrant further assessment for drilling.
"We have a number of additional drilling activities to undertake in the Pavo-1 well before moving the drilling rig to the Apus-1 well location. Overall, we are extremely pleased with the Pavo-1 result and are looking forward to it adding significant value within what is now expected to be an expanded Dorado production hub.”