While fruits from the deepwater Gulf Wilcox are at hand with Lower Tertiary and Lower Tertiary Inboard discoveries, the Wilcox remains the frustrating carrot on a stick for the ultra-deep shelf players, despite well costs approaching a quarter-billion dollars. Meanwhile, the industry is evaluating a gradually expanding body of positive news onshore, where the Wilcox has become the focus of rejuvenation efforts involving new technological approaches to an oldie-but-goodie geologic target.

If the ultra-deep shelf play and the horizontal sorties onshore unfold as expected, new life is here for a venerable old geologic column that has offered an estimated ultimate recovery (EUR) of 24 trillion cubic feet of natural gas equivalent onshore since initial exploitation in the 1930s, to as much as 150 trillion cubic feet of natural gas equivalent from the ultra-deep shelf. Added to that is a potential resource of 15 billion barrels of oil equivalent (BOE) in the deepwater offshore following the initial Gulf of Mexico discoveries at BAHA 2, Trident and Great White a dozen years ago.

Recent news has originated onshore, where two public independents, Midstates Petroleum Co. and Unit Corp., are chipping away at the Wilcox in south-central Louisiana and southeast Texas.

Midstates is focusing on the Louisiana Wilcox in Beauregard, Allen and Evangeline parishes, where it is coaxing hydrocarbons out of an interbedded geologic column more than 3,000 feet thick, lying 9,000 feet or more beneath the surface. The company has reentered more than half a dozen legacy fields, applying horizontal drilling and multistage fracturing after employing 3-D seismic to guide the development program. Midstates completed four horizontal Wilcox wells during the second quarter of 2013, including three in North Cowards Gully Field and one in South Bearhead Creek at its DeQuincy area in Vernon Parish on the Texas-Louisiana border.

One well, Wood 10H-1, at North Cowards Gully, featured a strong initial production rate but encountered mechanical issues—a common element in the challenging Wilcox drilling. Based on the early well results, Midstates opted to sidetrack the well during the third quarter.

Elsewhere, Midstate's first horizontal well at South Bearhead Creek, Musser Davis 33-28 HC-1, was flowing at more than 400 BOE per day after 90 days online. Midstates subsequently completed Musser Davis 27 HC-1 in the Wilcox “D” bench during third-quarter 2013 at a total measured depth of 19,208 feet, including a 4,733-foot lateral. In mid-September, the well was producing at a choked-down rate of 967 BOE per day, 80% oil, from 11 frac stages.

Wilcox production in Louisiana topped 5,500 BOE per day in mid-September from 170 producing wells scattered across four fields and 118,120 net acres, according to a Midstates investor presentation. It appears that both North Cowards Gully and South Bearhead are commercially attractive through horizontal drilling, although the independent is classifying its Wilcox efforts as marginally economic at the nearby West Gordon Field.

The Wilcox was a significant factor in Unit Corp.'s decision to raise 2013 production guidance, though the company also included contributions from its Midcontinent Mississippian Lime play. Unit's current Wilcox focus is Gilly Field in southeast Texas, where the company increased its estimated resource potential 31% to a net 220 billion cubic feet equivalent of natural gas following the 2012 discovery. The new estimate represents nearly one-fourth of Unit's 2012 proved reserves, though to date the company has booked only 30 billion cubic feet equivalent in proved Wilcox reserves.

Read the entire article in the Nov. 2013 issue of Oil and Gas Investor.

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