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EXPLORER
Zagorski
from page 32
led him to earn his master’s degree at the
University of Pittsburgh.
In 1992, Lomak Petroleum Inc. acquired
Mark Resources. Zagorski eventually
became manager of geology for Lomak,
which later became Range Resources
Corp.
He generated prospects in numerous
areas and formations, including a regional
unconventional play targeting the Trenton/
Black River Formation in New York, which
led to Utica/Trenton discoveries in the Clyde
Field.
His interest in the Trenton Black River
play grew out of regional studies related to
expanding several new high volume gas
discoveries being made in West Virginia
ZAGORSKI
and south central New York, which were
attracting significant industry interest.
“Although the Trenton Black River play
had been extensively developed early for oil
in the giant Lima Indiana field, that play had
not been successfully tested in the deeper
part of the Appalachian Basin,” he said.
“We ended up in 2000 putting together
a couple of acreage blocks down here in
southern Pennsylvania to test these deeper
reservoir concepts.”
“I had something new to
bring back to the company
– we had our own Barnett
Shale-style play here.”
‘A Barnett Shale Equivalent’
In 2003, Zagorski and his colleagues
identified a large, untested domal structure
in Washington County, Pa.
“Back at that time most of the
conventional wisdom on the Marcellus was
that it couldn’t be developed commercially.
It wasn’t in everyone’s psyche to be looking
at that play,” he said. “We wanted to drill
a formation that was shallower than the
Trenton/Black River but deeper than the
Marcellus on this structure.”
In 2003, Range Resources drilled a
well, the Renz Unit #1, to test the structure.
While significant shows were encountered,
attempts to complete and commercialize
these deeper zones failed, and the
company was preparing to plug and
abandon the well.
Zagorski thought the prospect still had
possibilities.
He was right. The Renz later became
famous as the start of the Marcellus Shale
play.
“In 2004 I went to visit a geologist in
Houston (Gary Kornegay) I’d worked with
years before in Utah’s Uinta Basin,” Zagorski
recalled. “He had a prospect he wanted
me to look at in the Neal/Floyd Shale in the
Black Warrior Basin in Alabama,” Zagorski
recalled.
Part of the prospect pitch included a
comparison of the Floyd as an analog to the
Barnett Shale.
“At that time I hardly knew what the
Barnett Shale was,” Zagorski said.
He soon found out, and similarities to the
Marcellus were striking.
“That was the point in time I had the
‘Holy smokes!’ moment,” he said. “I
had something new to bring back to the
company – we had our own Barnett Shalestyle
play here.”
Zagorski said he took the concept to
then-Range Resources CEO Jeffery L.
Ventura, a seasoned petroleum engineer
with both domestic and international
experience, who gave the project and
completion recommendation a green light.
The company went back to the Renz well
and tried a large, Barnett-style hydrofrac in
the Marcellus.
Resulting gas production for this first
vertical test started at around 300,000 cubic
feet a day (mcf/day), later topping out at
800,000 cubic feet a day (mcf/day), he said.
“That opened our eyes. What we did
then was to take a look at the formation a
heck of a lot closer than we had before,”
Zagorski said. “We ended up drilling two
more vertical confirmation wells. Then we
began drilling our first horizontal well in late
2004, 2005. That wasn’t any fun.
“Now the hard part started.”
The Dream Comes True
Recognizing the Marcellus’ potential,
Range Resources began leasing
aggressively in southern Pennsylvania to
add to its existing acreage positions. The
company’s Marcellus team drilled and
completed its first horizontal test in early
2006.
“It wasn’t as good as the vertical,”
Zagorski said. “The second didn’t get any
gas. The third was twice as good as the
first, but still not as good as we needed to
establish commerciality.”
Time was going by and costs were
piling up.
He credits Ventura with the long-term
vision to continually support and steer the
project, saying, “The senior guy was behind
the play from the very start.
“Jeff had a vision to transform Range
from a traditional exploration company to
one focusing on resource plays that were
highly repeatable and offered large scale
development,” he added, “so the Marcellus
really fit perfectly for his vision.”
Ventura will tell his own story about the
challenges of the Marcellus as he is the
keynote speaker for the Michel T. Halbouty
Lecture at ACE 2013 on May 20.
In 2007, they took what they had
learned from the first three horizontal tests
34 MAY 2013 WWW.AAPG.ORG
See Marcellus, page 38