AAPG Explorer - June 2010 - American Association of Petroleum ...

AAPG
EXPLORER
‘Crackle Frac’ some chalk
Rockies’ Niobrara Play Expanding
By LOUISE S. DURHAM, EXPLORER Correspondent
Gas was hot. Now it’s not.
Whiplash, anyone?
Owing to the past couple of
years when highly productive shale gas
plays have sprouted like weeds in myriad
locales in the United States, essentially in
sync with cratering demand, oil is king –
for now.
Given the current oil-gas price
differential hovering around 15:1 or more,
it comes as no surprise that a number of
E&P folks, principally independents, are
moving at near warp speed to stake their
claim in oil plays, particularly oil shales
and those rich in NGLs.
Meanwhile, some of the Big Guys, e.g.,
ExxonMobil, BP, Total and others, have
bought into the shale gas plays via joint
ventures and acquisitions, with the long
term in mind.
In addition to these deals, some of the
independents’ positions in shale gas have
begun to pay off, so these trailblazers
in commercial shale gas have cash on
hand to dig into something currently more
lucrative.
This is good news for the Rocky
Mountain region, which has been
pummeled by low prices and sinking
demand for natural gas.
There’s oil in them thar’ hills.
For example, operators have been
working diligently the past couple of
years to successfully wrest oil from the
high profile Upper Devonian-Lower
Mississippian Bakken shale play in
Montana and North Dakota.
According to a U.S. Geological
Survey assessment, the Bakken harbors
an estimated 3.65 billion barrels of
undiscovered, technically recoverable oil,
1.85 Tcf of associated/dissolved natural
gas and 148 mbo of natural gas liquids.
Early attempts to produce the Bakken
economically were an exercise in
frustration for the operators, and it was
usually looked on as a bailout zone. AAPG
member and 2006 Explorer of the Year
Dick Findley is credited with cracking the
10 JUNE 2010 WWW.AAPG.ORG
Photos courtesy of Randy Ray
Niobrara Formation-Fort Hayes member: Vertical fractures in thick bedded limestones, east
dipping outcrop, north of Boulder, Colo., along the Colorado Front Range.
code for the Bakken in 1995, ultimately
leading to development of the giant Elm
Coulee Field in the Bakken in eastern
Montana.
Today, the prolific Bakken has some
respectable competition.
For example, the underlying
Three Forks formation – which now is
considered to be separate from the
Bakken – reportedly may contain as much
recoverable oil as the Bakken, which has
more oil overall.
The North Dakota Department of
Mineral Resources has released more
conservative numbers than the USGS
estimate. It reportedly credits the
Bakken with a mere two billion barrels
recoverable, but also forecasts two
billion as well for the Three Forks, which
contains about one-eighth the total oil of
the Bakken.
Niobrara Potential
Higher up the geologic section in the
Cretaceous, there’s apparently a mother
lode just waiting to be seriously exploited.
“When you ask what’s happening in the
Rockies, the answer is oil shale plays,”
said Denver-based AAPG member Randy
Ray, “and the hot topic is the Niobrara.
“The Niobrara is part of the Cretaceous
seaway that covered the whole middle
of the U.S,” Ray noted. “We’ve had cycle
after cycle of exploration for Niobrara
fractures, mainly oil but some gas where
it’s buried deeper.
See Rockies, page 24