American Oil and Gas Reporter - January 2015 - 88

Unconventional Resource Science
duce twice as much and downhole electrical submersible pumps that produce even
more. We also are experimenting with gas
lift."
Continental's projected per well EUR
for its 2015 Bakken drilling program
stands at 700,000 barrels of oil equivalent.
Lateral length, artificial lift, density spacing, the number of frac stages and completion design are "all pieces that play a
role" in increasing EUR, according to
Gould. But he says the company is highly encouraged and is placing the most value on implementing its slickwater and hybrid completion designs.
Although each rock formation is different, he contends the technical lessons
learned can be transferred from one play
to another.
Come A Long Way
Craft laughs when asked how Approach Resources' efforts have progressed
since it drilled its first two Wolfcamp horizontal wells: the Cinco Terry No. 901 and
the University No. 4221, in late 2010.
"The first two horizontal wells were not
that good," he admits. "We had drilled
more than 600 deeper gas wells in this
area, and didn't know whether the horizontal program we were attempting would
work. In addition to the new play uncertainties, our projected horizontal well
costs were considerably higher than our
bread and butter vertical program. Going
from $900,000 per vertical well to $8.5

million per horizontal well was not something we took lightly.
"Our first horizontal well, the Cinco
Terry 901H, was a 5,000-foot short lateral that took us 50 days to drill. Our second well, the University 4221-1H, was a
7,100-foot lateral that took us 23 days to
drill," Craft recalls. "Each well had 15-21
frac stages, 300 feet per stage. We used
a gel water frac, which was recommended by our service provider. I tell people our
first two wells didn't make enough to
grease a tricycle."
Approach didn't give up, however.
Today, Craft says, the company is drilling
those same 7,500-foot laterals in 7-10 days.
He says Approach has 160,000 gross
acres in the southern Midland Basin, primarily in Crockett County, 107,000 of
which are prospective for its Wolfcamp
Shale horizontal program. Approach has
drilled 150 horizontal Wolfcamp wells to
date and has 136 producing horizontal
wells. Its horizontal EURs range from
300,000 to more than 800,000 barrels of
oil equivalent, resulting in a P-50 EUR
close to 500,000 boe, Craft reports.
"By the time we drilled our fourth
Wolfcamp horizontal well, we had refined
the frac treatment to slickwater-not a hybrid, but pure slickwater," he continues.
"We started seeing what we were expecting: average EURs of more than 450,000
boe a well."
Well costs have come down from
around $8.5 million when Approach start-

Since launching a pilot program to test horizontal drilling in the Wolfcamp oil shale play
in 2010, Approach Resources has drilled approximately 150 horizontal wells in the southern Midland Basin. Initial wells included a good deal of "science" for testing, cost as much
as $8.5 million for a 7,500-foot lateral, and took 50 days to drill. Today, the company says
it can drill the same wells in as little as 7-10 days and for $5.5 million apiece, which it says
is one of the lowest drilling and completion costs in the Permian Basin.

88 THE AMERICAN OIL & GAS REPORTER

ed testing the Wolfcamp to $5.5 million a
well in 2014. At $5.5 million, Approach
has the lowest drilling and completed well
cost of any Midland Basin operator, according to Craft.
The company has made a number of
other changes as well, Craft notes. It has
reduced its frac stage spacing from 300 to
240 feet, with some more recent wells being completed with 200-foot stages. It has
increased the sand concentration in its hydraulic fracturing program from 900
pounds per foot to 1,300 pounds with fourfive perforation clusters per stage. Craft
says that increase in sand concentration
with the reduction in spacing between frac
stages has been a key to the company's improved EURs.
"We are experimenting with sand concentrations up to 1,800-2,000 pounds per
foot, which is 13.5 million-15.0 million
pounds per 7,500-foot lateral," he reveals. "With the combination of higher
sand concentration and longer laterals, we
expect to see further improvements in
EURs.
He says Approach will drill a few
10,000-foot test laterals during 2015,
adding that drilling is the cheapest part of
a well. The completion is where the real
money is spent. "The challenge is increasing your EUR per foot without raising your
cost per boe," he cites, adding that it takes
12-16 months of production to get a feel
for how a well will perform long term.
Craft says Approach has done a number of other unique things that might be
listed as "best practices."
"We were the first to commercialize all
three zones of the Wolfcamp: the A, B and
C," he relates.
Craft explains that for a triple stack set
of wells Approach will drill the A bench
at about 5,600 feet and then move over 660
feet and drop down approximately 300 feet
to drill the B bench. The C bench lateral
is about 600 feet below the A bench lateral. He calls it a "Chevron pattern."
Approach employs zipper, or simultaneous completions, which Craft says do
not necessarily increase initial production,
but save money and increase the ultimate
reservoir recovery factor through better
conductivity between laterals.
Build Infrastructure
Because its acreage is contiguous,
Craft says Approach spent approximately $100 million to build a centralized in-

American Oil and Gas Reporter - January 2015

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