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Baker Oil
Tools' Coiled Tubing Solutions Handbook
Baker Oil Tools (Baker) recently released a
Coiled Tubing Solutions Handbook, which can be downloaded at
no charge in pdf format (www.bakerhughes.com/
bot/coiled_tubing/pdfs/coiled
_tubing_handbook.pdf).
Baker designed the handbook to highlight system capabilities
within eight distinct intervention areas where coiled tubing
can offer a highly effective and cost-efficient alternative.
The eight categories in the CT Solutions Handbook are: Well
Cleaning, Fishing and Milling, Zone Isolation, Stimulation and
Fracturing, Sand Control Completions, Flow Management, Plug
and Abandonment, and Sidetracking and Re-entry.
AAPG's
Winter Education Conference, February
14-18 in Houston
AAPG's second annual winter education conference in Houston
offers 11 different courses. There will be four concurrent
sessions going each day, and course timing is staggered
throughout the week so attendees can attend from two to four
courses. Courses range from one to three days in length.
New topics this year include, among others:
- Assessment, Classification and Reporting
of Reserves
- Characterization of Tight Gas Reservoirs
- Geochemical Exploration for Oil and Gas,
Strategies for Success
The full-week registration fee for AAPG
members is $1,095, or courses are priced individually.
For full course listing and more information visit AAPG's
website (www.aapg.
org/education/wec/index.cfm).
Stimulating Bakken Horizontal Wells, A Montana Case Study
In this SPE paper Wiley et al describe the
evolution of completion/ stimulation practices of horizontal
wells in the Bakken formation in a project in Richland
County, Montana. Here horizontals are oriented in the
direction of maximum principal stress (340°) to foster
longitudinal fracture growth. |
Early on, to control fracture initiation at
specific points, cemented liners and limited-entry perforating
were used to control fracture initiation and distribution of
the stimulation along the lateral. To reduce the probability
of vertical growth with little stress contrast between the
Bakken and overlying Lodgepole, wells were produced to create
some drawdown (increasing stress contrast) before hydraulic
fracturing. Although wells exhibited good productivity,
analysis of radioactive tracers showed the toe would
preferentially treat. Since cemented liners with limited-entry
perforating was not ensuring the entire lateral was being
treated, the completion/stimulation practice was switched,
evolving to current practice of non-cemented, pre-perforated
liners with a modified fracture treatment with diverter
stages. Four main changes
(non-cemented liners and longer laterals, staged treatment and
diversion, cleaner fracturing fluid with a more aggressive
breaker, more proppant per foot of lateral), which were made
simultaneously, resulted in a 30% production improvement and
reduced well costs.
Summarized from SPE 90697(Improved
Horizontal-Well Stimulations in the Bakken Formation,
Williston Basin, Montana; 2004 Annual Technical Conference)
available from
www.spe.org.
Completion
Engineering
Association The
Completion Engineering Association (CEA), which has been
active for almost 18 years, is an industry group created to
facilitate problem solving Joint Industry Projects (JIPs) in
the completions part of well construction. It provides a forum
for:
- Presentation of proposals for
completion-related projects sponsored by members for
participation by members and non-members alike
- Exploring member interest levels in
potential completion-related problems to aid in developing
future industry-sponsored projects
- Advising academic organizations and other
industry groups of the needs and interests of members
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Initial fee for full-voting members and
associate non-voting members is $500 and $250, respectively.
TheCEA awards a $1000 scholarship each year to a junior or
senior with a petroleum related major and an interest in
completions.
For more information visit
www.
completionengineeringassoc
iation.org.
Frac
Packing
Near Water Contacts Frac-packing
has become the preferred completion for Gulf of Mexico (GOM)
wells, but there are challenges for wells that have water
contacts within the production zones. However industry is
addressing the challenge. This article reports field
experience in 12 frac-packed GOM completions (five gas, seven
oil) in intervals having water contacts. Three of the 12 wells
had less than 10 ft of separation between the perforated
intervals and the water contacts, with separation in one well
being only four feet. Gas wells
responded more favorably with four of five being successful.
With one exception, all the oil wells reported low initial
water production—but in a couple wells with the water contacts
only four to six ft away, water production increased within
three months. The authors (Bruce Comeaux, Tim Landry and Marty
Usie of BJ Services and Guy Navaira of ChevronTexaco)
ultimately advised caution in gas wells with less than 10 ft
of separation, and in oil wells with less than 20 ft of
separation.
Candidate selection starts with evaluating
zonal isolation during primary cementing. Fracture modeling
using well information is done. If cross-linked fluid causes
excessive growth towards the water contact, linear gel fluid
can be used. In the field work most wells were frac-packed
using cross-linked gels. Treating volumes were reduced to
restrict growth into the water zone. Crossed-linked fluid
treatments were ramped quickly to achieve maximum proppant
concentrations of 10 to 12 ppg (pounds proppant per gallon of
fluid). Linear gel fluid treatments were limited to 4 to 8 ppg.
Future treatment fluids may include relative permeability
modifiers.
Excerpted from "Experience Ensures Sand
Control Success," Hart's E&P, October 2004, pp. 77-78. |
Tech
Transfer Track