Some of the biggest oil producers in the U.S. are zeroing in on an oil and gas play in Louisiana that has been around for decades but could soon become more of a household name.

That play, the Austin Chalk, has been the next big thing in U.S. oil and gas production before, seeing its last revitalization in the 1990s. Now probably better known as the Eagle Ford Shale's little brother, unconventional drilling techniques are bringing the play to life. EOG Resources Inc. and Marathon Oil Corp. have both picked up thousands of net acres in Louisiana prospective for the Austin Chalk.

"Historically, it's been a play that's been pretty well exploited, but with the focus on unconventionals the last 10 years or so, these kind of plays went out of fashion," said Andrew Slaughter, the executive director of Deloitte's Center for Energy Solutions. "But one of the benefits of unconventional production is that it can open new frontiers in conventional plays too. You can turn back on conventional plays and maybe revive them."

The Austin Chalk is rock from the Cretaceous Period and is a layer above the wider Eagle Ford Shale. As the name implies, it is not shale; it is chalk and fractures more easily. It is thinner than the Eagle Ford and varies in permeability. Like the Eagle Ford, it stretches from the Mexican border into Louisiana. In addition to EOG and Marathon's focus to the east, WildHorse Resource Development Corp. believes it holds approximately 100,000 acres for prospective Austin Chalk exploration in several counties of central Texas.

"The Austin Chalk play in Louisiana is experiencing a resurgence in activity. New horizontal drilling and completion techniques have resulted in substantial production rates," the state's Department of Natural Resources said, noting that it stretches across 12 different parishes. The play, according to the DNR, has produced 54.9 million barrels of oil and 246 Bcf of natural gas.

'A bit more complex'

The Austin Chalk has been exploited through conventional production methods for decades, but it has largely been overlooked in recent years as fracturing shale plays became the norm.

"Geologically, it is a bit more complex than the Eagle Ford," EOG Executive Vice President of Exploration & Production Ezra Yacob said during the company's first-quarter earnings call May 6. "It's not quite as straightforward to use a lot of those historical learnings. The way we're developing it is different and it's unique."

While it may be complex, the formation has similarities that are hundreds of miles apart. After drilling some successful wells in Karnes County, Texas, EOG went looking for went looking for similar rock; that search led them east.

"It's the same play, but a different spot. EOG had such great success on their Fuji and Kilimanjaro leases [in Karnes County] that they searched for where else that might occur. Avoyelles and St. Landry Parishes are where they found that," said Paul Cleveland, managing director of Houston-based Energy Capital LLC, whose firm has invested in the play.

One of EOG's first wells drilling in the Bayou Jack field in Avoyelles Parish reported 24-hour initial production totals of 1,120 barrels of oil and 1.16 MMcf/d of gas, which grabbed the company's attention.

As of mid-March, EOG had six operating wells in the Louisiana portion of the Austin Chalk. Marathon has kept quiet about their activities in the play so far, but it said it has a largely contiguous position in the area that it bought up for an average of less than $900 per acre.

"We see this as a natural extension of kind of this Austin Chalk megatrend that goes from Mexico across South Texas, all the way over to East Louisiana. And having been one of the leaders in the development of the Austin Chalk in South Texas, we think we're well equipped to get in here and appraise and understand the potential of this," CEO Lee Tillman said May 3.

Meanwhile, in Texas …

Houston-based WildHorse says it holds more than 400,000 acres in the Eagle Ford, largely northeast of the commonly thought of region southwest of San Antonio. Instead, the company is buying up acreage in Brazos, Burleson, Washington and Lee counties, largely agricultural areas between Austin and College Station. Quiet now, these areas were once a hotspot for drilling in the Austin Chalk and could be again.

"Historically, its core areas were in central Texas," Slaughter said of the Austin Chalk. "It's naturally fractured rock, so even with vertical drilling, you could get decent flow rates."

During its first-quarter earnings call, WildHorse said it completed four wells in the Austin Chalk during the quarter, with solid but gas-heavy totals. And like its counterparts operating elsewhere in the play, it has found areas of varying complexity.

"The Austin Chalk wells … take a little bit longer to drill than the Eagle Ford wells. I think you guys are all aware where it's deeper and hotter presents some operational challenges," COO Steve Habachy said during the company's first quarter earnings call.

WildHorse's first wells were in Washington County, but it believes that areas to the north, in Burleson County, will lead to increased oil production from the Austin Chalk. CEO Jay Graham said the company believes the chalk will have the same characteristics as the lower Eagle Ford.

"Much like the Eagle Ford trend where we're oilier in the north in the shallow areas and gassier in the south deeper areas, you got the same trend in the Austin Chalk," he said.

While WildHorse has given little information on its Burleson County activities and did not return requests for comment, Cleveland said it is well-known they are hurriedly exploring the Austin Chalk in the northern-most county. "They're killing a boatload of acreage they bought around Burleson," he said.

With oil prices in excess of what most producers had budgeted for this year, excess capital is flowing in. That could mean a rebirth for the Austin Chalk and other plays like it. If an E&P company has acreage in the Eagle Ford, Slaughter said, odds are good that they can drill into and exploit the Austin Chalk as well.

"They've got a bit of a freebie, haven't they?" he said. "It's shallower and has lower-intensity completions. So with the price sets we have now, the economics should be quite attractive."