Wireline logs have now confirmed that Winchester Energy (ASX: WEL) has hit more oil pay at its latest White Hat Ranch well in Texas’ Permian Basin than its nearby producing well in the field.
The US-focused oil producer and explorer has been drilling the White Hat 20#3 well on the Mustang prospect for the past two weeks, with oil and gas shows observed while drilling through the Wolfcamp D shale, Strawn lime, Strawn sand and the Caddo formation.
The company today announced that wireline log interpretation of the primary Strawn sand target has indicated 28 feet of net oil pay from a gross 52ft oil-bearing interval between 5918-5970ft.
This is an encouraging result for Winchester as this net pay exceeds the 20ft found in the White Hat 20#2 well, located 510m away and which initially produced 200 barrels of oil per day when placed on production after mild frack stimulation around two years ago.
The Strawn sand is high to prognosis, has greater average porosity and is thicker than the 3D seismically predicted thickness of 35-45ft, the company reported.
In addition, wireline logs have confirmed a cumulative net oil pay of 71ft for the Wolfcamp D shale, Strawn lime and other secondary targets including the Caddo formation.
Targeting the Mustang prospect, White Hat 20#3 is the first in a three-well exploration campaign planned across Winchester’s Permian Basin acreage, with the two remaining wells to target the El Dorado and Spitfire prospects.
Winchester is aiming to define a combined best to high estimate prospective resource of 7.8-17.5 million barrels of recoverable oil from the three prospects.
While White Hat 20#3 is considered an exploration well, it is a step out well of the initial ‘discovery’ well White Hat 20#2, and therefore represents the second successful penetration of the 3D seismically mapped Strawn sand stratigraphic trap referred to as the Mustang prospect.
This prospect alone hosts a prospective recoverable resource target of 2 million barrels of oil at best estimate and up to 5 million barrels on a high estimate basis.
“We now have two wells on the Mustang prospect that support our interpretation from 3D seismic mapping and extensive well control that a significant Strawn sand stratigraphic trap is present that has not been previously recognised,” Winchester managing director Neville Henry said.
“The result of this well gives us confidence that our seismic modelling of the Mustang prospect is working and has de-risked the expected results from future wells to be drilled on the Mustang prospect,” he said.
Mr Henry added that further wells would need to be drilled to determine the ultimate size of the oil resource present in the Strawn sand.
White Hat 20#3 has now been cased for production testing of the Strawn sand and preparations are underway to continue drilling ahead in the Ellenburger carbonate formation.
Ellenburger, which has produced 150,000 barrels of oil with an initial production rate of 100bopd from the nearby JF#3 well, will be open-hole tested before the workover rig moves up to production test the Strawn sand.
Winchester said its focus was on the Strawn and Ellenburger targets, with no immediate plans to production test the interpreted net oil pay in the secondary targets.
According to the company, all the completion and production facilities are lined up so the well can be production tested and placed on production rapidly.
Winchester has a 75% working interest in the drilling of White Hat 20#3, with private company Carl E Gungoll Exploration holding the remaining 25% stake.