Winchester Energy (ASX: WEL) is preparing to launch a new hydraulic fracturing and production testing program at its White Hat 39#1L oil well, moving to the shallower Strawn formation from which another well in the Texan oilfield has been producing oil for the past year and a half.
The Permian Basin-focused explorer and producer today reported drill rig mobilisation has been scheduled for 17 September with fracture stimulation operations to begin on 26 September.
Hydrocarbons were encountered during horizontal lateral drilling of the Ellenburger formation in White Hat 39#L in June, prompting Winchester to move straight to production testing.
The company reported encouraging initial oil recoveries from the well after it was placed on pump in early July, but over the course of several weeks the lateral was unable to sustain commercial flow rates.
As a result, Winchester has decided to move up-hole to focus on the shallower oil-bearing Strawn formation, in which strong oil shows were observed while drilling.
The Strawn formation is a proven producer in the nearby White Hat 20#2 well, which initially produced 200 barrels of oil per day.
This well has produced more than 30,000bopd over the past 17 months and is currently producing at an average rate of 40bopd (in August 2018).
The Strawn formation is a thick, consistent unit of carbonate debris sand with more than 6m of good porosity and permeability.
Winchester managing director Neville Henry said the formation is believed to hold significant oil resource potential both in structural and stratigraphic traps within the company’s large leasehold.
“The Strawn formation is a known producer in the East Permian Basin, with the company’s White Hat 20#2 well having been a valuable contributor to company revenue over the past year,” he said.
According to the company, White Hat 39#1L’s latest fracking and production testing program has been designed similar to the successful Strawn-targeted program implemented for White Hat 20#2.
Last month, Winchester announced plans for a refocused vertical drilling campaign, designed to exploit multiple reservoir stacked targets in the Wolfcamp D organic shales, Strawn and Ellenburger formations.
Two drilling prospects have been shortlisted: El Dorado and the Strawn Channel.
According to Henry, project partner US Energy has notified Winchester that “they are planning to commence a fracture stimulation of the Lower Penn/Wolfcamp D formation in the vertical wellbore of Thomas Ranch 119H in mid-September 2018. This first test of the shale oil potential of the Wolfcamp D formation in Winchester’s large leasehold could upgrade the untested resource potential of this formation.”