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Horizontal
Barnett Shale Wells, To Cement or Not
Horizontal drilling is now commonly used in
the Barnett Shale. Pinnacle Technologies looked at Devon
Energy's first 23 horizontal wells in the "Core" area. All
horizontal pilot wells were cased for borehole stability and,
by number were about equally cemented and un-cemented. The
laterals were 1,000-4,000 ft in length. Current waterfracs are
large, and with longer horizontals, multiple stage fracs are
required.
Pinnacle noted that, "while cemented
horizontal wells allow for more control of fracture initiation
locations, problems are often encountered in achieving
fracture initiation. Excessive near wellbore pressure losses
with accompanying low injection rates and high treating
pressures are often observed in cemented wells. Procedures to
alleviate the problem including re-perforating, jet cutting
holes, acidizing, and pumping gel and sand slugs are not 100%
successful. These steps add time and cost compared with a
problem-free treatment." The logical
question then becomes, to cement or not. Pinnacle evaluated
production data, on a MMCFD/1000 ft of horizontal lateral
length basis, for "cemented" versus "uncemented" wells. There
is a compelling graph (Fig. 4) in their newsletter that
reveals that uncemented completions have a statistical
production advantage over cemented completions in the pilot
area.
The article is an interesting read. Those
playing the Barnett are urged to read the entire article.
Excerpted from Pinnacle Technologies, Inc. Winter 2005
newsletter, which can be viewed online at
www.pinntech.
com/subs/newsletters_list.html.
Missed
the CO2 Conference in Midland?
The annual CO2 Conference in Midland has become the
premier CO2 flooding event in the industry. Those
of you with an interest in CO2 flooding who were
unable to attend last December's event are encouraged to read
an extended |
summary published in the American Oil and Gas Reporter's
February 2005 issue. Developed by Steve Melzer, director of
the Conference, the article briefly summarizes several case
studies from fields in several states and the interplay of
CO2 flooding with the growing carbon
sequestration movement.
USGS
Yukon Flats (Alaska) O&G Potential
Yukon Flats is a region of low, forested
hills and flatlands with numerous streams and lakes,
situated generally to the east of the Trans-Alaska Pipeline
System in east-central Alaska. U.S. Geological Survey (USGS)
scientists recently finished their first detailed assessment
of the undiscovered oil and gas potential of the Yukon Flats
Tertiary Composite Total Petroleum System.
The assessment indicates the probable
existence of technically recoverable oil and gas resources,
with mean estimates of about 5.5 trillion cubic feet of
undiscovered natural gas, 173 million barrels of
undiscovered oil, and 127 million barrels of natural-gas
liquids in conventional accumulations. These volumes are
those that are technically recoverable using current
technology and that have the potential to be added to
reserves in a 30-year forecast span. The assessment was
based on a comprehensive review of available information,
including new data from USGS field and laboratory studies.
No petroleum production has been obtained
from Yukon Flats, with the one exploratory well finding
small quantities of natural gas.
The Yukon Flats National O&G Assessment
Fact Sheet 20045-3121 is available at
http://pubs.usgs.gov/
fs/2004/3121.
Generating Pipeline-Ready Natural Gas From Abandoned Coal
Mines TA unique
technology developed by Engelhard Corporation is enabling a
Southern Illinois gas producer to treat and sell gas from |
abandoned coal mines and
contaminated natural gas that would otherwise remain
unrecovered in shut-in wells. By implementing Engelhard
Molecular Gate adsorbent-based technology, Grayson Hills
Energy, LLC is removing water, nitrogen (N2) and
carbon dioxide (CO2) from gas produced from its
coal mines and natural gas wells.
A system is offered as a
prefabricated, modular plant based on patented Molecular Gate
adsorbent materials and separation process. It is generating
significant interest among gas producers due to its economical
processing cost, easy start-up and operation, and
environmental friendliness.
he Engelhard technology enables
Grayson Hills Energy to treat up to 2.5 MMscfd. The system is
located at the wellhead and is powered by an on-site
gas-driven generator that uses tail gas from the Molecular
Gate adsorbent-based process as fuel. The facility includes an
integrated dehydration unit to remove water and simultaneously
removes about 7% carbon dioxide and 12% nitrogen while
delivering product with less than 4% nitrogen; as required by
the interstate pipeline. The process operates by adsorbing
contaminants at high feed pressure while delivering the
product sales gas with minimal loss of pressure. This ability
to deliver methane at near feed pressure minimizes compression
requirements. The technology is offered as a modular packaged
plant through an engineering and fabrication partner.
For more information, visit Engelhard's
website
www.engelhard.
com/Lang1/xDocID54651F74B
5FA4F78B7454D4E19D0CDF8/
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view/MarketID54651F74B5FA
4F78B7454D4E19D0CDF8. |
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