Devon Energy Corp. sees potential for tighter spacing and increased drilling inventory in the overpressured oil window of Oklahoma’s STACK play, where it is increasing drilling and investment (OGJ Online, Aug. 2, 2016).
The company’s third spacing pilot targeting the Mississippian Meramec formation tested a seven-well pattern across a single-section interval in the upper part of the formation.
Initial 15-day production rates in the Pump House pilot averaged 2,200 boe/d, 55% oil, and cost $6 million/well.
Drilled with 4,700-ft laterals, the Pump House wells were completed with 2,200 lb/lateral-ft of proppant across 35 frac stages with perforation clusters 25 ft apart.
Choke sizes increased gradually over the initial 15-day periods to 26/64 in. from 14/64 in.
The Pump House wells are in Kingfisher County adjacent to Devon’s Born Free pilot and 3 miles north of its Alma pilot.
Average 120-day production of the Born Free pilot’s two wells is 1,400 boe/d/well. Average 60-day production of the Alma pilot’s five wells is 1,300 boe/d/well.
Tony Vaughn, Devon chief operating officer, said the flow rates exceed type-curve expectations with minimal interference between wells.
The company is conducting more than 10 additional spacing pilots, preparing for full-field development in 2017.
The pilots test as many as eight wells each in a single Meramec interval, evaluating joint development of multiple, stacked-pay intervals.
In eastern Blaine County, Devon recently started production at high rates from two extended-reach Meramec wells, Marmot 19-1HX and Blue Ox 3130-4AH.
Drilled with 10,000-ft laterals, the wells reached average peak 24-hr rates of 3,700 boe/d/well, 70% oil, on 28/64-in. chokes. Completion of the Marmot and Blue Ox wells used 2,600 lb/lateral-ft of proppant across 50 frac stages, 30 ft apart.
Vaughn said the wells help the company understand optimum development of its STACK properties.
“It is our expectation that we will develop the majority of our stacked-pay Meramec position with extended-reach laterals, which will significantly increase rates of return from this world-class reservoir,” he said.
Devon is adding as many as four operated rigs to the play in the second half of 2016, bring the total to as many as six. It expects to invest $450 million in the play this year, up 40% from an earlier estimate.