A federal agency estimates that the Haynesville and Bossier formations collectively contain more than quadruple the amount of natural gas thought to be in place in 2010 as well as 4 billion barrels (Bbbl) of conventional oil resources.

Collectively, the Bossier and Haynesville assessments outstrip estimates made earlier in the decade of the Marcellus and Utica shales, making it the largest continuous natural gas assessment the U.S. Geological Survey (USGS) has ever conducted.

New evaluations of the Bossier and Haynesville, including onshore, state waters and a portion of the U.S. Gulf Coast, estimate mean natural gas of 304.4 trillion cubic feet (Tcf) and NGL of 1.9 Bbbl, according to updated USGS assessments. The assessments are predictions of estimated undiscovered, technically recoverable resources.

A 2010 assessment of the Bossier and Haynesville formations examined Jurassic and Cretaceous rocks of the Gulf Coast. At that time, the Bossier was estimated to contain a mean of 9 Tcf of natural gas and the Haynesville 61.4 Tcf.

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“It’s amazing what a little more knowledge can yield,” said USGS scientist Stan Paxton, lead author of the assessment. “Since the 2010 assessment, we’ve gotten updated geologic maps, expanded production history and have a greater understanding of how these reservoirs evolved. All of that leads to a better geological model and therefore a more robust assessment.”

In 2011, the USGS estimated the Marcellus’ mean undiscovered natural gas resource of 84.2 Tcf and a mean undiscovered NGL resource of 3.4 Bbbl within the Appalachian Basin Province. In addition, a 2012 Utica assessment found it contained about a mean resource of 38 Tcf of undiscovered, technically recoverable natural gas.

A USGS spokesman said in an email that the agency is in the process of revisiting its Marcellus assessment but “our new estimate won’t be complete for at least a year.”

The Bossier and Haynesville have long been known to contain oil and gas, but it wasn’t until 2008 that production of the continuous resources got underway in East Texas and North Louisiana—the primary production areas for the two formations, USGS said.

The area fell out of favor with producers due to a plunge in commodity prices and an upswing in Marcellus production.

While in the long shadow of the Permian Basin, the Haynesville continues to gain traction among operators. The play has been reinvigorated by 2016 A&D activity; the April 10 IPO filing of a pure play Haynesville E&P; and proximity to LNG export terminals.

The Bossier and Haynesville formations lie within the Gulf Coast Basin, which extends from the Texas-Mexico border in the west to the Florida Panhandle in the east.

“As the USGS revisits many of the oil and gas basins of the United States, we continually find that technological revolutions of the past few years have truly been a game-changer in the amount of resources that are now technically recoverable," said Walter Guidroz, USGS program coordinator for the Energy Resources Program. “Changes in technology and industry practices, combined with an increased understanding of the regional geologic framework, can have a significant effect on what resources become technically recoverable.”

USGS assessments are probabilistic and statistic assessments, yielding a range of possible resource amounts.

Undiscovered resources are those that are estimated to exist based on geologic knowledge and statistical analysis of known resources, while technically recoverable resources are those that can be produced using currently available technology and industry practices. Whether a resource is profitable to produce is not been evaluated.

Continuous oil and gas is dispersed throughout a geologic formation rather than existing as discrete, localized occurrences, such as those in conventional accumulations. Because of that, continuous resources commonly require special technical drilling and recovery methods, such as hydraulic fracturing.

Darren Barbee can be reached at dbarbee@hartenergy.com.