Some are calling it Louisiana Eagle Ford

Nuisance Zone Becomes Oil Target

Oil appears to be in no imminent danger of losing its current designation as “King of The Patch,” given the continuing lofty price per barrel.

In stark contrast, natural gas just can’t get any respect these days.

Even the recent Hurricane Isaac elicited little more than a collective yawn from the commodity traders as it made a slow trek across the Gulf of Mexico with its considerable gas production.

The ongoing high oil price makes a slew of drilling targets attractive, including some long-tantalizing yet elusive ones.

A striking example is the new/old Tuscaloosa Marine Shale (TMS) play in central Louisiana.

The Cretaceous-age TMS extends across at least 2.7 million acres in the Bayou State and into southwestern Mississippi. The shale occurs between the upper and lower units of the Tuscaloosa formation, which has produced tremendous volumes of hydrocarbons from fields in the famed Tuscaloosa Trend, including the dynamic Port Hudson, Judge Digby, Morganza and others.

Production comes from the lower Tuscaloosa Massive Sand facies.

It’s generally thought that the deep, high-pressure TMS sourced the highly productive sands in the Tuscaloosa Trend.

Even so, the TMS was long considered to be a nuisance zone when the drill bit penetrated. On occasion it would throw oil, which captured the attention of geoscientists over the years.

Early attempts to produce the TMS in the 1970s failed to yield commercial results. However, the last hole drilled in 1977 in northern Tangipahoa Parish continues to kick out a few bopd even today.

Sleeping Giant Ready to Awaken?

Current high interest in the TMS can be traced principally to a 1997 study estimating seven billion barrels of oil awaiting recovery. The study and resulting publication originated at Louisiana State University’s Basin Research Institute, which now is the Basin Research Energy Section of the Louisiana Geological Survey.

Owing to the study’s conclusions, the TMS might best be viewed as a sleeping giant all set to waken with a roar via modern sophisticated technologies, including horizontal drilling and multi-stage hydraulic fracturing.

The now-official play is still relatively new, coming to the fore around 2008 when the former Encore Acquisition drilled four horizontal wells, which encountered varied problems.

The estimated seven billion barrel carrot has attracted some high profile companies who have snapped up considerable acreage:

  • Encana – 355,000 acres.
  • Devon – 316,000 acres.
  • Indigo Minerals – 250,000 acres.
  • EOG – 200,000 acres.
  • Goodrich Petroleum – 132,000 acres.
  • Halcon Resources – 55,000 acres.
Kirk Barrell
Kirk Barrell

As of the end of August there had been 13 completions reported in this current era of the play, according to AAPG member Kirk Barrell, president of The Woodlands, Texas-based Amelia Resources, which generates prospects and seeks out partners.

Barrell, who has presented at various professional societies about the play, has become a go-to source of information via his continuing blog on all things TMS.

Having worked this general part of the world for 23 years, he has significant insight into the current happenings.

“It’s been proven the reservoir can flow at high rates,” Barrell said. “We’ve had two wells at just over 1,000 barrels a day and have proven a completions strategy.

“We’re still waiting to see what the declines look like because we don’t have many wells that we’ve seen 12 months production on,” he emphasized. “So the jury is still out on the decline rate.”

He noted the biggest hurdle now is well costs in the range of $13 million to $15 million, with the target range being perhaps $10 million to $11 million. The average TVD is about 12,500 feet, with the focus being on the updip oil window rather than the much deeper gas window.

Barrell asserted that there’s no question the TMS play has staying power.

“All plays’ costs start off high and reduce through time as best practices get defined, and I have no question this play will be the same,” he said. “We have a great group of operators bringing a lot of expertise in the horizontal realm who will figure out how to get the drilling and production costs down.”

‘Louisiana Eagle Ford’

The relatively recent arrival of EOG, with its finely honed Eagle Ford shale expertise in Texas, sparked still more optimism that this play is the Real Deal.

In west-central Louisiana, the TMS is referred to as the Louisiana Eagle Ford by some operators. They note that it is similar in age and lithology to the highly productive, liquids-rich Cretaceous-age Eagle Ford interval in Texas.

This can make for a good marketing tool, but it does raise some eyebrows.

Barrell said most players hope to get everyone to clarify this because it’s the same exact play and the same stratigraphic interval. He did point out that the TMS has higher resistivities to the east, which may indicate more hydrocarbon saturation.

Indigo Minerals has drilled in the western part of the TMS without yielding production, and Halcon is leasing and permitting nearby, according to Barrell.

Devon’s seven wells, including an initial vertical pilot well, have been drilled to the east, principally in St. Helena and Tangipahoa parishes with a recent sojourn into West Feliciana Parish. Its most recent well at 13,700 feet TVD is the deepest to date in the play; initial potential was due to be announced at press time.

The next several months could tell an impressive story, particularly as the EOG well results begin coming in.

Additionally, Devon appears poised to become more aggressive in that it reportedly announced recently that future wells will be 8,000-foot laterals, meaning proppant use and fracturing jobs will increase.

Looking Ahead

In case you’re wondering about the role of 3-D in the play, Barrell noted that the major players likely are biding their time on this until they have the play to a commercial level. He anticipates that a large 3-D program will kick off when that occurs.

Barrell emphasized that within the next six months or so more decline rate info will be available.

“This play could be very large,” he enthused. “It’s oily, it covers a large geographic area and we have very good operators – and it’s a place where a lot of hydrocarbons have been found before.

“We think this very viable play will be proven to be commercial in 2013,” he added.

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Emphasis: Gulf Coast