By John Kemp
LONDON, July 5 Pressure to respond to falling
oil and gas prices by cutting operating costs, coupled with the
need to reduce the social and environmental footprint on host
communities, will force fracking firms to employ a more targeted
approach to drilling wells and hydraulic fracturing in future.
More than a million fracturing operations have been
conducted in the United States since 1947, according to the U.S.
National Petroleum Council, yet in many ways the technology is
In many instances, fracturing remains an expensive, brute
force exercise that wastes resources while causing unnecessary
disruption to affected communities.
The relative inefficiency of current fracking approaches was
highlighted by Paal Kibsgaard, chief executive of oilfield
services company Schlumberger, in a speech back in March
Too many wells are being drilled into parts of shale
formations that have poor production potential, Kibsgaard said.
The horizontal section of wells are often being fracked at
regular intervals along the entire length even though
significant parts of the laterals have limited or no production
potential because the geology is not favourable.
And in many cases the amount of horsepower and water being
applied in each fracking operation is excessive. Massive
fracturing networks are being created that extend more than can
be propped open with frack sand, and where the unpropped part
offers little or no contribution to production.
FINDING SWEET SPOT
In a recent report, researchers for the U.S. Geological
Survey (USGS) concluded that "production from the most
productive wells in an area is commonly more than 100 times
larger than from the poorest productive wells."
For gas wells drilled into the Haynesville Sabine Platform,
which lies under parts of eastern Texas and Louisiana, the most
productive are expected to yield 20 billion cubic feet of
natural gas over their lifetime. But expected ultimate recovery
(EUR) from the median well is just 2 billion cubic feet, and at
the low end some wells will yield just 20 million cubic feet,
according to the USGS.
In the case of oil wells drilled into heart of the Eastern
Expulsion Threshold of North Dakota's Bakken Formation, which is
the most productive part of the whole area, the best wells are
expected to yield as much as 5 million barrels, but the median
expected is just 120,000, and some of the worst wells may yield
as little as 2,000.
Indiscriminate drilling and fracking imposes enormous
unnecessary disruption on local communities and is hugely
expensive for drilling firms.
For a gas well "each hydraulic fracturing stage pumps around
300,000 gallons of water and up to 200 tons of sand down a well"
according to Rick Carr and Sam Pearson of Deloitte Consulting in
an article published in "Oil and Gas Journal" ("Unconventional
drilling requires managing transportation logistics" June 4).
"A typical development in the Marcellus region can result in
20,000 to 30,000 truckload movements per (drilling) rig per
year. Compound these requirements by the fact that there are a
total of 138 rigs operating in Marcellus and it becomes easy to
understand how transportation is such a concern. Similarly, an
estimated 270 rigs are now active in the Eagle Ford, and
capacity constraints are becoming a concern" they write.
Carr and Pearson emphasise the importance of careful
logistics management to minimise disruption and reduce costs.
According to Deloitte's Wellsite Logistics Model, four wells
drilled from a single pad can involve 1,200 truckloads of water
for the fracturing and over 800 truckloads of gravel, with more
truck movements for equipment and other supplies.
Moving a single rig can involve "50-60 truckloads of large,
heavy equipment over a 10-mile distance over a six-day period,
while fluid hauls involve the constant movement of more than 200
loads of fresh and produced water each day".
Careful management can minimise traffic, but the most
effective way to cut costs and disruption is to avoid drilling
unnecessary wells in low productivity areas, and avoid
unnecessary fracturing stages in parts of laterals that have
little or no chance of yielding gas, condensates or crude.
"The combination of optimised well location, well path and
completion design is the key in achieving more with less, in
terms of production, recovery and costs" according to
Schlumberger cites one completion in the Marcellus where the
client achieved 40 percent higher production, in part by
fracking only the intervals around the best quality shale rather
than spreading them evenly over the horizontal length.
Schlumberger hopes its UniQ seismic surveying system, with
improved imaging quality, "will help better predict the
variations in shale reservoir quality" and permit better
Rather than be in the business of providing vast amounts of
horsepower, which Schlumberger sees becoming commoditised, the
firm wants to focus on technology like imaging and specialist
fracking fluids, where it will continue to have more market
With natural gas prices under intense pressure in North
America, and at least some analysts predicting oil prices have
peaked for the time being, other production and services
companies seem set to follow Schlumberger in following a more
The focus is shifting from brute-forcing fracking to a more
targeted and technology-intensive approach that seeks to
minimise waste and costs, while boosting output per well,
thereby doing more with less, and reducing the damaging effects
on the environment and local residents.
(1) "Kibsgaard speaks at 40th annual Howard Weil energy
conference" March 26, 2012:
(2) "Variability of distributions of well-scale estimated
ultimate recovery for continuous (unconventional) oil and gas
resources in the United States" USGS, 2012: