To understand why Bill Zagorski is getting AAPG’s Outstanding Explorer Award at the upcoming AAPG Annual Convention and Exhibition in Pittsburgh, you have to travel far, far back into the distant reaches of Deep Time.
All the way back to 2004.
It’s hard to believe now, but back then the industry was just awakening to how the technology from the successful Barnett Shale development in Texas could be applied to unlock other North American shale plays.
Zagorski was in Pennsylvania, working a play for Range Resources Corp. and evaluating a well that passed through the Devonian Marcellus Shale. He had the idea of using Barnett-style horizontal drilling and high-volume hydraulic fracturing to develop the Marcellus.
What happened next is exciting, informative, dramatic, instructional and perhaps even inspirational – a success story that has become part of the industry’s lore.
Today, Zagorski serves as vice president-geology for Range Resources-Appalachia LLC in Southpointe, Pa.
A native of Pittsburgh with bachelor’s and master’s degrees in geology from the University of Pittsburgh, he was named “Father of the Marcellus” by the Pittsburgh Association of Petroleum Geologists in 2009.
And this year he receives AAPG’s Norman H. Foster Outstanding Explorer Award, to be presented at the AAPG Annual Convention and Exhibition in Pittsburgh, and given “in recognition of distinguished and outstanding achievement in exploration for petroleum or mineral resources, by members who have shown a consistent pattern of exploratory success.”
“I had an interest in science and geology from a very early age,” Zagorski recalled. “I was drawing dinosaurs on a tablet when I was four or five and collecting rocks with my dad when I was seven.”
Although he began his university studies majoring in chemistry with a minor in mineralogy, he soon switched to geology – but not yet with a focus in oil and gas.
“I didn’t have the ‘Ah-ha!’ moment in petroleum geology until I finished undergraduate school,” he said.
Zagorski went to work for Atlas Energy Group Inc. in Pittsburgh, then moved on to new independent Mark Resources Corp., which he called “a great career opportunity.”
“I started getting familiar with the Devonian Shale and the Marcellus when I took that job in 1983,” he said. “Back in that time there was quite a bit of research going on in the Department of Energy, and you had the Section 29 tight sands tax credit, so you were looking at $8, $9 per mcf gas prices.”
At Mark Resources he became interested in Western Canada’s Elmsworth Field – and legendary AAPG geologist John Masters’ basin-centered gas concepts.
“It’s not uncommon now, but at the time it was quite unconventional as it went against the anticlinal theory,” he said.
Zagorski used these concepts to study the huge Clinton Medina fields in Ohio and Pennsylvania and came up with a major success: generating the prospect that became the Cooperstown Gas Field in Pennsylvania and led to the drilling of thousands of wells. These studies also 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 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.”
‘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 Shale-style 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 and drilled the fourth horizontal test of the Marcellus. This time, they moved the landing of the horizontal well 20 feet higher in the section.
Immediately following this discovery the company drilled and completed three more successful horizontal wells in a row, each more productive than the fourth.
That provided the breakthrough needed. That well tested at 3.2 million cubic feet a day, the company’s and industry’s first commercial horizontal Marcellus well.
Range Resources announced those results in late 2007, and in 2008 the Marcellus Shale play went into overdrive. Some predicted the Marcellus would become the biggest producing gas field in the United States.
In 2012, it did.
“I thought my strength was in my conviction,” Zagorski said. “I feel very blessed to have been given the opportunity to be part of the early pioneering of shale gas.”
Maybe I’m Amazed
When industry people talk about finding successful approaches to get high production from a reservoir, they often call it “unlocking the play.” The Marcellus had been unlocked, but developing it was far from easy.
“There were no experienced crews up here,” Zagorski said. “It was a real challenge.
“One of the critical breakthroughs was Range started a technical office here in Southpointe, Pa., in 2007, led by Texas Barnett shale veteran Ray Walker, now Range’s COO, from Fort Worth. This office was then staffed with people who were focused specifically on developing the Marcellus,” he added.
In the end, shale play development proved an old exploration home truth once again. To get good oil and gas production, go where the oil and gas is.
“I’m a big proponent of looking at old gas shows,” Zagorski said. “It seems to me the bigger and more consistent the gas shows, the better the reservoir.”
“The reason I think the Marcellus and other recent shale plays got missed is that, prior to the Barnett, it was believed that there had to be natural fracturing for shale plays to produce commercially, like the Big Sandy Field in Kentucky and West Virginia. In that field they were using various stimulation designs, early on shooting with explosive followed by various frac methods, most often nitrogen foam fracs,” he said.
The new approach to unlocking shale production with large-scale water fracs and horizontal drilling “seems so simple now, but it was largely untested and counterintuitive up until 2004 with the Barnett play successes,” he noted.
Range Resources now claims between 26 trillion and 34 trillion cubic feet (Tcf) equivalent of resource potential in the Marcellus Shale, and another 12-18 Tcf in the Upper Devonian shales above the Marcellus.
Zagorski hadn’t seen that coming.
“Initially, in my studies, I couldn’t get my estimate of the prospect potential to the company past a half a Tcf, or even a Tcf,” he said.
He’s amazed, even dazed, at where successful development of the Marcellus Shale has led.
“All that work I had done in various plays and prospects over the last 30 years,” he said, “we can achieve in a matter of months now.
“It really is amazing.”