the first time in a long time, an exploration play in the Appalachian
Basin is sparking the interest and imagination of oil companies
around the country, thanks largely to advances in seismic operations,
drilling technology and geologists’ understanding of a complex play.
The productive zone lies in the formations of the
Ordovician-age Trenton-Black River, which started the John D. Rockefeller
empire over 100 years ago and is once again padding the bottom lines
of Appalachian Basin operators.
Charleston (W.Va.)-based Columbia Natural Resources
touched off the recent frenzy of activity there when the firm brought
in some impressive wells on its acreage in New York’s Finger Lakes
This was unexpected. The Trenton-Black River has
not been a major target in the Appalachian Basin because the zone
is deeper than traditional producing reservoirs in the basin.
But the firm’s geoscientists had been studying the
Trenton-Black River for years - and all that work finally has come
Äolumbia’s success with its basin-wide deep drilling
program is proving that the Appalachian Basin still holds tremendous
potential - and the lower 10,000 feet of sediment are virtually
“This is the most exciting thing to happen to the
Appalachian Basin since the early 1950s,” said Alan Fairman, business
manager with Fairman Drilling in DuBois, Pa. “We are even starting
to get inquiries from large independents based in the Southwest.”
Kathleen Sanford, with the New York State Department
of Environmental Conservation’s Division of Mineral Resources, agreed.
“We hear reports of dozens of landmen in New York,
and a recent state lease sale seems to bear out those reports,”
she said. “In a 1999 state lease sale we had record bids as high
as $312 per acre for some acreage in Schuyler County - our previous
high bids were in the $60 to $70 range. That lease sale was held
just a couple of weeks after a successful discovery well happened
in Steuben County, and landmen who were in Wyoming and Louisiana
at that time tell us they heard about the well.”
Currently the state is preparing another lease sale,
and 23,000 acres have been nominated.
“That’s a tremendous amount of acreage to be nominated
in New York, and we are expecting the same level of interest that
we saw at the 1999 sale,” Sanford said. “All 23,000 acres nominated
are in the Trenton-Black River play area.”
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Today four fields are producing deep gas from the
Trenton-Black River in Steuben and Chemung counties of southwestern
New York, and the wells in these new fields, according to those
involved, have been phenomenal.
Columbia in 1999 had expanded its Trenton-Black River
program and made a discovery in Roane County, W.Va., that was geologically
similar to its wells in New York.
Richard Beardsley, vice president of geology and
geophysics with Columbia, said the company’s last two wells in West
Virginia were the largest wells in the northeast United States in
terms of open flow rates.
In fact, the West Virginia discovery well - drilled
to 10,300 feet on Columbia’s Vineyard Ridge area - demonstrated
an open-flow rate estimated at approximately 50 million cubic feet
of gas a day.
Bottom hole pressures initially gauged at 6,600 pounds
per square inch - highly unusual for typical Appalachian Basin production
- were sustained through the first month of production.
The second well in the Cottontree Field posted a
natural flow from about 9,600 feet and was operationally similar
to the discovery well.
Columbia has completed a five-mile, eight-inch gathering
line connecting the new field to Columbia Gas Transmission’s nearby
high-pressure interstate pipeline. Since the gathering line was
completed the firm is averaging about 7.4 million cubic feet of
gas a day from the field.
Today Columbia is drilling its fifth well in the
Cottontree Field. Beardsley said the West Virginia prospect is more
than 20 years old.
“Advances in drilling technology that now allow us
to drill to 10,000 feet and deeper at a reasonable cost, combined
with the successes in the Trenton-Black River in New York, brought
this West Virginia prospect to the forefront,” he said.
These recent wells aren’t the first Trenton-Black
River wells in the state.
“The first Trenton-Black River well was drilled in
1936 and burned the rig to the ground,” he said, chuckling, “a good
indication hydrocarbons were present.”
Patience Pays Off
The New York activity that touched off the interest
in the Trenton-Black River has been a long time coming as well.
Columbia first began studying the Ordovician formations
in the early 1970s, when the firm was looking for Devonian reefs
in New York and acquired about 900 miles of seismic data. Scientists
didn’t confine themselves to Devonian targets, however, and looked
at additional horizons on the seismic.
“At that time we also looked at old wells that had
penetrated what we believed were hydrothermal reservoirs,” Beardsley
said. “We modeled this area after what we saw in western Ontario,
where some old fields dating back to 1917 produce from hydrothermal
reservoirs in the Trenton-Black River.
“That production in Ontario, coupled with the Lima-Indiana
Field, which started the seven sisters for John Rockefeller, certainly
indicated the Trenton-Black River formations were worth examining
in the Appalachian Basin,” he added. “Our work and samples we saw
indicated that a deep-seated heat source generated a hydrothermal
cell that provided mobilization of magnesium rich waters deep in
the reservoir, which created hydrothermal cave systems.”
The one-and-a-half-billion-year-old Greenvillian
Orogeny likely became the fundamental route for all the deep-seated
basin features found in this play area.
“Basically, we are now looking at areas where major
separation and rotation of the basin created networks of faults
and fractures that provided conduits for the hot water,” he said.
Columbia’s first test of the Trenton-Black River
in 1980 was a dry hole.
“(But) we took the information gleaned from that
well and developed geologic models for the play,” Beardsley said.
The first Trenton-Black River discovery in New York
came in 1986 at Columbia’s Gloades Corners Field, but a combination
of industry and corporate problems added 10 years before that first
discovery came on line.
“It was difficult to generate management interest
for a new play concept in a region isolated from pipelines, but
by the mid-1990s we revisited the area and drilled a successful
offset well one mile from the Glodes Corner discovery,” Beardsley
The company then built a pipeline to service the
region, and that, according to Beardsley, “was the key to expanding
the drilling program.”
Today Columbia has made 10 new Trenton-Black River
field discoveries in New York - seven solo and three through joint
Columbia’s success and new seismic studies sparked
several additional operators to join the play.
Fairman Drilling and partner East Resources of Pittsburgh
currently have about 30,000 acres under lease in West Virginia and
are continuing to expand their holdings. The firms were drilling
their sixth Trenton-Black River well at year-end and this year plan
to drill about 18 wells in south central New York.
By mid-year the partners plan to begin testing acreage
in West Virginia, according to Alan Fairman.
East Resources first approached Fairman Drilling
in early 1998 about establishing a joint venture to purchase regional
seismic and develop some prospects in the play. Reports from the
firms’ geologic consultants, Orion Resources Consulting in London,
Ontario, indicated some very promising potential.
Next, the two companies shot about 40 miles of additional
seismic to identify drill sites. At the same time the firms began
acquiring acreage, and by the summer of 1999 had about 180,000 acres
Today the joint venture has acquired over 150 miles
of new seismic and has 250,000 acres, Fairman said.
Fairman and East Resources drilled their first well
in March 1999 and made a discovery at the No.1 Broz in Chemung County.
The well was drilled to 9,303 feet and initial open flow estimates
were in excess of 15 million cubic feet of gas a day. That well
will be going on line later this year.
A dry hole just north of the discovery well followed,
but last summer the firms’ third test, the No. 1 Whiteman, was a
success. That well, sited seven miles west of the Broz, was drilled
to the Black River at 9,511 feet, encountering natural gas shows
of over 12 million cubic feet of gas a day.
The joint venture’s fourth well was drilled seven
miles north of the Whiteman well in Schuyler County on state lands.
The SRA 2 No. 1 well went to 8,770 feet and found a natural gas
flow of over 30 million cubic feet of gas a day.
Last fall the two companies completed a one-mile
offset to the Broz that flowed an estimated 15 million cubic feet
of gas daily. Currently the joint venture is sidetracking its sixth
well after drilling into an unproductive section of the Black River
at 10,400 feet.
By mid-year three of East Resources and Fairman Drilling’s
wells are expected to be on production.
“Following Columbia’s success, this play was appealing
to our company because we had the capabilities to drill to these
depths, and due to availability of acreage in New York,” Fairman
“Also, Orion Resources had experience with the Trenton-Black
River in Ontario, and the firm’s geologists said the features on
our seismic were far more pronounced than what they see in Ontario.”
The economics of the play is an obvious plus.
“Our wells have cost from $850,000 to $1 million
to drill to about 10,000 feet, but once they go on line we could
have situations where we will pay out the wells in just a couple
of months,” Fairman said. “When was the last time you saw that in
the Appalachian Basin?
“These wells are not typical Appalachian Basin discoveries.
The potential for large production volumes is significant - the
formation we are drilling into is 350 to 400 feet thick, but we
have only drilled into the top 30 to 40 feet because of the large
amounts of gas we have coming out the flow line.
“That’s a nice problem to have.”
Pennsylvania General Energy is the third major player
in the New York Trenton-Black River play. Late last year the firm
was drilling its fifth Trenton-Black River well after netting four-for-four
Generally the Black River is a shallow-water carbonate
overlain by the deeper water Trenton formation, which is an argillaceous
The productive zones in these Ordovician carbonates
are centered on fault or fracture systems. The carbonates have been
dolomitized by hot, magnesium-rich water tracking up the faults
and fractures, said Robert Trevail, with Orion Resources.
Seismic has been important to recent successes, and
in general operators are looking for:
- Structural depressions over the dolomitized zone.
- Vertical displacement of the underlying Precambrian basement
- A change in character on seismic records within the dolomitized
Non-porous limestones typically bound the reservoirs.
“Unlike traditional plays where you look for highs
on the seismic, we are looking for lows - slumps that indicate a
dolomitized zone,” Trevail said.
Now that geologists have a better understanding of
the properties of productive Trenton-Black River plays the Appalachian
Basin - as well as the entire eastern United States - could see
a boom in activity searching for analogous settings.
“The Trenton-Black River formations are pervasive
over an enormous area of the north and eastern regions of the country,”
said Brian Keith of the Indiana Geological Survey. “The rocks are
everywhere - the key is finding the fracture systems that allow
these dolomitized reservoirs,”
“When you look at a map you can see that the Trenton-Black
River runs all the way from the St. Lawrence Seaway to Kentucky,”
Fairman said. “With a better geologic understanding and improvements
in seismic technology, there’s no reason to think that analogous
plays won’t be found in other regions.”
And that’s good news for operators in the northeast
where big, exciting exploration plays don’t come along every day
- or every decade, for that matter.