Following the recent discovery of oil shows while drilling the Lightning prospect, Winchester Energy (ASX: WEL) has begun completion activities at its Arledge 16-2 well in Texas’ Permian Basin.
In mid-July, the US-focused oil producer announced wireline logs had confirmed 25 feet of calculated net pay in the upper Cisco sand plus 20ft in the lower Cisco sand.
In an update today, the company said further processing of data has resulted in a recalculation of potential net pay in the targeted lower Cisco sand.
“After the formation image log was processed, thin beds of sandstone and siltstone were identified that are below the resolution of conventional logging,” Winchester reported.
“The high-resolution resistivity was used to recalculate potential net pay, increasing the 20 feet of net pay to 50 feet of net pay,” it stated.
This upgrade also increases the potential gross pay of the sand interval to 190ft.
Winchester said it will now evaluate the entire sand interval from the bottom up using conventional completion technology, planning to perforate and test four separate intervals totalling 91ft between a depth of 5,010 and 5,131ft. The entire interval will then be fracked if required.
The upper Cisco sand, which has a gross interval of 165ft and potential net pay of 50ft, will be retained as a behind-pipe resource until the lower sand is evaluated as a potential “comingling opportunity”, the company said.
Winchester managing director Neville Henry said Arledge 16-2 will be a “very important well to Winchester, particularly if the test of the full lower Cisco sand interval is successful”.
“Seismic has identified several stratigraphic wedges in the Cisco and Canyon sections that could have these and/or similar sand units preserved over both the McLeod and Arledge leases,” he said.
Winchester’s McLeod lease is located to the east of Arledge, between it and the White Hat Ranch lease, which hosts the company’s Mustang oilfield.
In its June quarterly report released last month, the company said Arledge 16-2 could open “another development opportunity” to add to the recent Mustang oil discoveries.
The Lightning prospect has a best-estimate gross prospective resource of 1.95 million barrels of oil in the lower Cisco sands.
The Cisco sands are a proven producer in the area, particularly in the Bast field located 1.6km to the northeast of Winchester’s acreage.
The sands have historically produced a total of 5 million barrels of oil and 2.25 billion cubic feet of gas.