It's an unconventional success story of a New Yorker and a Californian "re-winning" in Wewoka.
It reads a little like a story from the Roaring ’20s.
Two young men – a New Yorker and a Californian – meet, go their own ways but eventually meet up again. They pool their talents and resources, take a gamble on an old, worn-out piece of property – and become Oklahoma oil barons.
OK, not oil barons exactly. But Lance Ruffel’s and David Pulling’s ventures helped make “a lot of good livings for a lot of people,” Ruffel said.
AAPG members Pulling and Ruffel (the New Yorker) met in the 1970s as geology students at the University of Oklahoma. Each went on to some success as an oil finder. Then in 1998 they teamed up and went into the Wewoka oil field, an Oklahoma reservoir that bloomed in the 1920s but wilted over ensuing decades.
With new technology and old-fashioned perseverance, Ruffel Oil Co. today has more than 100 wells that together are producing over 1,000 BOPD, plus an extensive planned drilling program in the region.
Rising oil prices sparked renewed interest in fields like Wewoka, which was considered depleted and abandoned in the 1950s.
The geologists both saw potential in the area – but one challenge, Pulling said, was “getting out in front of the play.”
They looked along the pinch-out and drilled into the Hunton Limestone, first tested by the Dixie Oil Co. in 1925 – and their initial efforts were not economical. The first try “bombed,” and competitors snapped up another while they were researching it, Pulling said.
Drawing on their experiences in different parts of the state, they shifted their completion practices. Instead of sand and acid fracturing, they tried high-velocity water fracking with limited entry.
“It seemed to work,” Ruffel said.
Indeed. One-hundred twenty wells later, Ruffel Oil is drilling its second horizontal well – and the dusty little town of Wewoka and the rest of Seminole County are experiencing new vigor.
“It’s not like the ’30s,” Pulling said, “but it affects a lot of people.”
Improved Approaches – and Technology
The Wewoka reservoir is unconventional, with water throughout the 200-foot hydrocarbon column, Pulling said, adding that early day oilers used perforation techniques and skipped the wet zones.
“We get the whole zone,” he said, with oil cut averaging 15 percent.
Secondary objectives like the Gilcrease, Wilcox and Bartlesville formations also have been productive targets, he said.
Wewoka, like other historic fields, has pros and cons.
“You know there’s oil in place – the challenge is how to get it out,” Pulling said.
Ruffel said the early efforts “were intelligent,” but some things were overlooked or bypassed as unprofitable.
Data is abundant, but mostly on paper.
“Dave and I both went over old completion records, well logs, scout tickets, survey reports ...” he said. “You have to be willing to look at a lot of information and organize a lot of information.”
Wells are fairly shallow – about 4,000 feet, he said – with low permeability.
Decline rates vary from well to well, Ruffel added. Some actually improve. Most average about 80 percent decline in the first year, then flatten out, making a quick payout (less than one year) important.
Despite steep decline, wells in the Wewoka have long lives. Some wells owned by Ruffel have been producing since 1935.
Estimated recovery per well is 50,000 to 70,000 BO and equivalents. Since 2000, Ruffel Oil has produced 1.9 million barrels of oil and eight BCF gas – or 3.2 million barrels of oil and gas equivalents.
“It’s not the sort of prospect for a major to come in and just buy up the countryside,” he said.
Modern efforts also come with modern baggage.
“We bought 15 wells to rework,” Pulling said. “Plus, you have to drill disposal wells at $1 million per well.”
But new technology makes their approach more surgical.
New 3-D seismic data, for example, revealed more complexity in what once was seen as a simple structure, Ruffel said.
Their approach today is “more stratigraphic than structural,” he said.
Pulling said working mature fields requires being flexible and adaptable, but quips: “I’m 62 – I didn’t want to learn a lot of new stuff.”
The two geologists sometimes have different interpretations, but have mutual respect and a common goal.
“This is our living,” Pulling said. “We’re not promoters – we’re spending our own money.”