This article from Bloomberg delves into some detail on how the unconventional 
oil sector is actually based on unreliable numbers -- with reserve estimates 
and production curves that have proven to have been wildly overstated -- to the 
point of criminal conspiracy to defraud investors (I would argue)

http://www.bloomberg.com/news/2014-04-03/old-math-casts-doubt-on-accuracy-of-oil-reserve-estimates.html

Old Math Casts Doubt on Accuracy of Oil Reserve Estimates

Jan Arps is the most influential oilman you’ve never heard of.
In 1945, Arps, then a 33-year-old petroleum engineer for British-American Oil 
Producing Co., published a formula to predict how much crude a well will 
produce and when it will run dry. The Arps method has become one of the most 
widely used measures in the industry. Companies rely on it to predict the 
profitability of drilling, secure loans and report reserves to regulators. When 
Representative Ed Royce, a California Republican, said at a March 26 hearing in 
Washington that the U.S. should start exporting its oil to undermine Russian 
influence, his forecast of “increasing U.S. energy production” can be traced 
back to Arps.
The problem is the Arps equation has been twisted to apply to shale technology, 
which didn’t exist when Arps died in 1976. John Lee, a University of Houston 
engineering professor and an authority on estimating reserves, said billions of 
barrels of untapped shale oil in the U.S. are counted by companies relying on 
limited drilling history and tweaks to Arps’s formula that exaggerate future 
production. That casts doubt on how close the U.S. will get to energy 
independence, a goal that’s nearer than at any time since 1985, according to 
data from the U.S. Energy Information Administration.Photographer: Ken 
James/Bloomberg
To replace the Arps calculation, researchers are testing new formulas with 
names worthy... Read More
“Things could turn out more pessimistic than people project,” said Lee. “The 
long-term production of some of those oil-rich wells may be overstated.”
Calculate Reserves
Lee’s criticisms have opened a rift in the industry about how to measure the 
stores of crude trapped within rock formations thousands of feet below the 
earth’s surface. In a newsletter published this year by Houston-based Ryder 
Scott Co., which helps drillers calculate reserves, Lee called for an industry 
conference to address what he said are inconsistent approaches. The Arps method 
is particularly open to abuse, he said.
U.S. oil production has increased 40 percent since the end of 2011 as drillers 
target layers of oil-bearing rock such as the Bakken shale in North Dakota, the 
Eagle Ford in Texas, and the Mississippi Lime in Kansas andOklahoma, according 
to the EIA. The U.S. is on track to become the world’s largest oil producer by 
next year, according to the Paris-based International Energy Agency. A report 
from London-based consultants Wood Mackenzie said that by 2020 the Bakken’s 
output alone will be 1.7 million barrels a day, from 1.1 million 
now.Photographer: Matthew Staver/Bloomberg
U.S. oil production has increased 40 percent since the end of 2011 as drillers 
target... Read More
U.S. crude benchmark West Texas Intermediate fell 41 cents to $99.21 a barrel 
at 10:10 a.m London time in electronic trading on the New York Mercantile 
Exchange. It has risen 0.8 percent this year.
Inherently Uncertain
Predicting the future is an inherently uncertain business, and Arps’s method 
works as well as any other, said Scott Wilson, a senior vice president in Ryder 
Scott’s Denver office.
“No one method does it right every time,” Wilson said. “Arps is just a tool. If 
you blame Arps because a forecast turns out to be wrong, that’s like blaming 
the gun for shooting somebody. As far as Arps being old, the wheel was invented 
a long time ago too but it still comes in handy.”
Rising reserve estimates gives the U.S. a false sense of security, said Tad 
Patzek, chairman of the Department of Petroleum and Geosystems Engineering at 
the University of Texas at Austin.
“We have deceived ourselves into thinking that since we have an infinite 
resource, we don’t need to worry,” Patzek said. “We are stumbling like blind 
people into a future which is not as pretty as we think.”
The Arps formula is only as good as the assumptions a company puts into it, 
Patzek said. Estimates can be inflated when Arps is based on limited drilling 
history for data or on a few high-performing wells to predict performance 
across a wide swath of acreage. Forecasts can also be skewed higher by assuming 
slower production declines than Arps observed.
Reserves Cut
In November 2012, SandRidge Energy Inc. cut its reserve predictions to the 
equivalent of 422,000 barrels per well from 456,000. Five months later, the 
estimate was cut again, to 369,000 barrels, company records show. Oklahoma 
City-based SandRidge has since made an adjustment upward to 380,000 barrels per 
well.
The early, more optimistic forecasts were based on a small number of 
high-performing wells, which led the company to overestimate performance for 
its other acreage, said Duane Grubert, SandRidge’s executive vice president for 
investor relations and strategy. The company now has more than 1,100 wells and 
has improved its drilling. It is confident that current estimates are reliable, 
Grubert said.
“Nobody knew that until we actually ground-truthed the field by drilling it,” 
Grubert said. “What we came up was, hmm, that initial estimate was a little 
high.”
Future Production
SM Energy Co., a Denver-based producer, suffered a similar setback this year 
when its wells in the Eagle Ford shale in Texas fell short of forecasts. The 
company on Feb. 18 cut its prediction in one area to the equivalent of 475,000 
barrels per well from 602,000. Estimating future production from early data is 
a challenge for the industry, said Brent Collins, a spokesman for SM Energy.
“This is especially true when you are trying to estimate an average from a 
limited number of wells,” Collins said.
Both SandRidge and SM Energy use variations of the Arps method, company records 
show.
Tapping shale formations differs from the drilling in Arps’ day, said Dean 
Rietz, an executive vice president in charge of reservoir simulation at Ryder 
Scott. The first commercial shale well was drilled in 2004, 59 years after Arps 
published his method.
Gas Pockets
In 1945, oil production meant drilling straight down to hit pockets of oil and 
gas that had become trapped after migrating upward from deep layers of rock. 
Today’s drilling targets those deep layers, boring through thousands of feet of 
the earth’s crust, then turning sideways to chew for a mile or more through 
layers that are harder and less porous than a granite countertop. The rock is 
shattered by a high-pressure jet of water, sand, and chemicals to create a 
network of small cracks to allow the oil and gas to escape. The largest 
fissures are narrower than the width of a paper clip. The smallest are 
thousands of times thinner than a human hair.
On a graph, these fractured wells appear to follow a different trajectory of 
decline than the conventional wells Arps studied, said Lee.
To replace the Arps calculation, researchers are testing new formulas with 
names worthy of indie bands: Stretched Exponential, which Lee helped develop; 
the Duong Method, devised by Anh Duong, principal reservoir engineer for 
ConocoPhillips; and Simple Scaling Theory, which the University of Texas’s 
Patzek worked on.
Rietz has made a well simulation model to predict production.
“Come back to me in 10 years, and I’ll tell you how reliable it was,” he said.

-- 
You received this message because you are subscribed to the Google Groups 
"Everything List" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to everything-list+unsubscr...@googlegroups.com.
To post to this group, send email to everything-list@googlegroups.com.
Visit this group at http://groups.google.com/group/everything-list.
For more options, visit https://groups.google.com/d/optout.

Reply via email to