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Owl
Creek Prospect
Noble Ridge Unit
Madden Field & Owl Creek Thrust Trend
Fremont County, Wyoming
Executive
Summary
The OCT, LLC has
assembled more than 23,000 gross/net acres along the Owl
Creek thrust trend and Madden Field areas of the
northeastern portion of the Wind River Basin, which are
being offered for sale as an exploration and development
opportunity.
The Noble Ridge Unit
consists of 23,682.31 acres adjacent to and north of the
Madden Unit. A 15,000' Lance test is proposed as the initial
required unit well to be located NENE-3-T39N-R90W. The
required Unit well will need to be drilled after July 16,
2006 and before November 15, 2006, as defined by current
lease and access road stipulations.
The circuit, arcing
geometry of the Owl creek thrust at the Noble Ridge,
combined with a thick, south dipping subthrust stratigraphic
section results in a potential Lower Ft. Union/Lance field
approximately 8-10 miles long by 3 miles wide.
Lance development
drilling potential could reach more than 500 wells, based
upon 40 ac spacing.
An additional 14,800'
Lance development well is proposed on a 386-acre fee lease
within the Madden Unit Boundary. The Philp-Knapp No. 1-18,
NWSW-18-T39N-R39W, targets 1090' feet of CNL-FDC gas pay
found in an offset well, the Shelter No. 1-19. Completion of
this development well will have an immediate economic
impact.
Air-mag and 2-D CDP
seismic data confirm the low angled nature of the thrust
which sets up a highly prospective subthrust fairway, which
is 12-18 miles wide by 50-60 miles long and has been
overlooked by previous exploration efforts.
The Lance Formation in
the northeast portion of the Wind River basin is
approximately 5000' gross thickness with up to 2000' net
sand. Both the upper and Lower Cretaceous section are
expected to be geopressured up to a gradient of 0.55
psi/ft.
Improvements in
drilling technologies have reduced overall costs, drilling
times, and reservoir damage, while the use of flow through
composite frac plugs results in higher initial flow rates
and ultimate gas reserves.
Multiple subthrust gas
prospect areas have been identified in this gas-rich, high
economic impact area. These prospects utilize the Madden and
Cave Gulch Fields as geologic analogs and could be further
delineated with 3-D seismic surveys. Burlington Resources is
presently permitting an approximate 60 square mile 3-D
survey covering much of the Noble Ridge Unit
Area.
The submitted leases
target exploratory potential for large subthrust anticlinal
structures with potential reserves ranging up to several
TCFG and multi-million barrels condensate from the Madison
Formation as well as the shallower pays of the Shannon,
Frontier, Mesaverde, Lance, and Ft. Union
Formations
Introduction
Oil and gas
exploration in the Madden and Cave Gulch Field areas of the
Wind River Basin dates back to the early 1950's. The Pure
Oil, Badwater No. 1, was drilled to 11,143' on what was then
termed the Badwater structure in 1949. The well was deepened
in 1957 to 16,869' and tested gas from 223' of pay in the
Lance Formation. The Field was later re-discovered in June
of 1968 by Wolf Exploration by the drilling of the Madden
Deep Unit No. 1, located NWSW-2-T38N-R90W. Madden Field is
characterized by thrust fault bounded anticlinal geometry
and gas production from multiple stratigraphic horizons of
the Lower Ft. Union, Lance, Mesaverde, Shannon sands, and
the Madison dolomite. The field covers more than 30 square
miles and is located about six miles south of the surface
trace of the north dipping Owl Creek Thrust. Severe seismic
velocity variations which masked the true structural relief
and formation damage caused by drilling and completion
fluids, slowed initial continuous development of the
field.
Burlington Resources
is the current operator of the Madden Field. Burlington has
focussed their efforts on the prolific Madison dolomite,
located at depths of 25,000'. Gas reserves for the Madison
Formation are estimated to range between 2.6 to 4 TCFG, with
net pay reaching 250' and a proven gas column of more than
1200'. Initial daily production rates per wellbore range
from 40-50 MMCFGPD. These rates have been constrained due to
processing capacity. These wells are capable of higher rates
as calculated AOF's of more than 150 MMCF have been
recorded. The Madison is currently producing 8-9 BCFG
per month from 7 wells. This is about 300 MMCFGPD gross
production from the Madison Formation., oran average 43
MMCFGPD per well.
Produced gas from the
Madison contains about 12% H2S and about 21% CO2. The
remaining hydrocarbon content is essentially methane.
Burlington has recently doubled the plant's gross inlet
capacity from the 130 MMCFD to 310 MMCFD. The plant is
presently in operation.
Burlington Resources
has improved Lower Ft. Union economics by employing a 100
well slim hole drilling program, targeting the uppermost
500' of the Lower Ft. Union formation. Utilizing a rig
dedicated to slim hole technology, Burlington has realized
cost reductions a now drills these wells in less than 7
days.
Burlington has
additionally focused their efforts on the Frontier formation
and plans a pilot coalbed methane program in the Lower Ft.
Union.
The Lance has produced
approximately 40 BCFG in the Madden Unit Area. The
productive potential of the Upper Cretaceous was only in
part understood. The Cody Formation was generally the target
of earlier wells, and the Lance Formation was rarely tested.
Fieldwide downdip limits have not been identified in the
Cretaceous reservoirs. Presently, these sands have been the
subjects of improved drilling and completion technologies as
well as the advances in 3-D seismic acquisition and
interpretation. Improved transportation out of the area has
resulted in continued activity.
The Bullfrog, Waltman,
and Cave Gulch areas followed a similar development history.
The Chevron Waltman No. 1 was drilled during 1959 to a total
depth of 11,899' in the Cody Shale. Both the Lance and the
Fort Union were found to be productive. Subsequent
development drilling sporadically continued over the next 40
years continuing with the Barrett Resources Cave Gulch No. 1
discovery in December 1994. The discovery of the Cave Gulch
Field has sparked a re-newed interest for Cretaceous
subthrust targets along the footwall of the Owl Creek
Thrust.
Regional
Setting
The assembled acreage
is located on the northeast flank of the Wind River Basin in
central Wyoming, approximately 90 miles northwest of Casper.
It is located along the Owl Creek thrust on trend with Cave
Gulch Field and within the boundary of the Madden Unit. The
northeast flank of the Wind River Basin was also the
depocenter for both the Fort Union and Lance
Formations.
Cave Gulch
Field
The Cave Gulch Field
was discovered by Barrett Resources by the drilling of the
Cave Gulch Federal No. 1 located NENE-31-T37N-R86W in
Natrona County, Wyoming. The prospect was based upon the
realization that the Waltman No. 1, SW/4-31-T37N-R86W, had
produced more than 18 BCFG, but had never been offset to the
northeast. The well was drilled north of the Waltman Field
through the Owl Creek thrust into the Upper Lance Formation.
The well encountered 481' net pay in a 2200' interval of the
Lance and the Fort Union Formations. This well flowed 10
MMCFGD and has produced about 17.1 BCFG and 73.6 MBC from
perforations in just 246' of pay between 5742 and 6811'
through March 2002. Gas production for the Cave Gulch
Federal No. 1 averaged about 900 MCFD during 2005
The Cave Gulch Unit
encompasses just 440 acres.
Continued development
at Cave Gulch has resulted in successful completions in the
deeper pays, including the Frontier, Muddy, Dakota, and
Lakota Formations. The Muddy has huge potential as evidenced
by the Cave Gulch No. 1-29, which blew out and produced up
to 100 MMCFGPD through drillpipe to the sales line.
Cumulative production has reached 13.6 BCFG from Muddy
perforations at 18,154' to 18,204'. The offset, the Cave
Gulch No. 3-29 tested up to 61 MMCFGPD from perforations at
about 16,750' to 18,148' and production has totaled 14.3
BCFG. Moncrief has recompleted the No. 16-1 Teepee Flats,
NESW-16-T37N-R86W for 8 MMCFGPD from the Muddy.
Regional
Structure
The Owl Creek thrust
is an east-west trending low angle thrust fault that
overrides the north flank of the Wind River Basin. The Owl
Creek thrust fault and it's associated faults and en echelon
folds dominate the prospect area. Detailed surface mapping
indicates at least two periods of activity along the thrust.
Northwest trending structures, which can be 6-10 miles long,
predate a younger east-west trend. Northwest trending
structures were uplifted during late Cretaceous and
Paleocene time, while the east-west system was uplifted
during the early-middle Eocene. The Owl Creek Range was
uplifted and thrusted over the subsiding Wind River Basin
during the Eocene and truncated the previously existing
northwest trending structures, similar to features along the
Casper arch. Horizontal displacement along the fault trend
ranges from 12 to 18 miles
Exploration efforts
have previously focused upon anticlinal structures located
in front of the surface trace of the Owl Creek Thrust, such
as the Madden anticline. To date, there exists a 12-18 mile
fairway beneath the thrust, which is 50-60 miles long and is
virtually unexplored. Established gas production from the
Fort Union, Lance, Frontier, and Muddy Formations at Cave
Gulch, and from the Frontier and Muddy Formations at Tepee
Flats prove the extraordinary potential of this prolific
trend.
Stratigraphy
The Tertiary Lower Ft.
Union, the Cretaceous Lance, Mesaverde, Frontier, Muddy and
Mississippian Madison Formation are the primary targets in
the project area. The NE portion of the Wind River Basins
contains more than 26,000' of sedimentary
section.
Sandstone reservoirs
of the Lower Ft. Union and Lance Formations are gas
saturated throughout the Project area. The stacked fluvial
sequences of the Lance and Lower Ft. Union are approximately
8400' thick where preserved and have an east-west trend.
Lower Ft. Union sands immediately underlying the Waltman
shale have been an important target in both the Madden and
Frenchie Draw areas. The lower part of the Lower Ft. Union
and Lance are described as interbedded lenticular sandstones
and shales, ranging from 10-50' thick. These units generally
exhibit gas effect on CNL-FDC logs. Log calculated
porosities may reach 20% in the better-developed sands and
natural fractures enhance reservoir permeability. X-ray
diffraction analyses of the Lance at Cave Gulch field
indicate the presence of kaolinite (31-55%), illite/smectite
(10-49%), chlorite (13-28%), and smectite
(8-14%).
The Meeteetse
Formation and the Lewis consist of interbedded sands, coals,
and shales throughout the project area. These sands
generally exhibit CNL-FDC gas effect where log porosity
exceeds 8%.
The Mesaverde is
approximately 1200' thick at Madden and can be divided into
three members. The uppermost unit is the Teapot sandstone.
The middle member is usually non-productive and is a series
of non-marine sands, shales and coals. The lowermost unit,
informally named the Fales sand, is about 200' thick and is
productive throughout the Madden area. The Fales sand is
described as very fine to fine grained, calcareous, well
sorted, and contains variable clay content. The Fales is
interpreted to represent sands deposited in a prograding
barrier bar environment. The original pressure gradient in
the Mesaverde is 0.73 psi/ft.
The Cody shale
contains the Sussex and Shannon sands. The Shannon sands are
described as two coarsening upward bar sands that range in
thickness from 10-60'. Shannon reservoirs are geopressured
to a gradient of 0.76 psi/ft. at Madden. Although many
Shannon reservoirs appear to be tight based upon log
analysis, the zones have produced significant volumes of gas
due to reservoir enhancement due to naturally occurring
fractures.
The Upper Cretaceous
Frontier consists of a series of coarsening upward,
lenticular sequences ranging up to 20' thick. Log porosities
can be 15%. Mudlog gas shows are common in the Frontier at
Madden.
The Muddy sand has
been a very important producer at Cave Gulch Field, and flow
tested gas at Hells Half Acre. It is believed that a Muddy
thick extends across the northeastern area of the Wind River
Basin.
The Mississippian
Madison Limestone was deposited on a broad shelf and is
about 400' thick. It consists of interbedded limestones and
dolomites with occasional ooilitic grainstones. Net pay can
reach 250'.The Madison is more dolomitic eastward along the
Owl Creek Mountains. The Madison dolomites at Madden are
found at 25,000' drill depths and display porosity up to
15%.
Noble
Ridge Unit Area
The Noble Ridge Unit
contains 23,682.31 acres. The proposed well will play off
the structural style of the Owl Creek thrust system where
the primary thrust has overridden the northwestward
continuation of the Badwater anticline. The relatively low
angle of the Owl Creek thrust fault leaves room for both
Upper & Lower Cretaceous strata through the Madison
underlying the thrust. The initial required test well is
located along the leading edge of the Owl Creek thrust,
analogous to the Cave Gulch Field.
A 15,000' Lance test
is proposed for the NENE-3-T39-R90W. The location will test
an approximate 7500' thick series of Lower Ft. Union and
Lance sands, which dip south and flatten into the leading
edge of the Owl Creek thrust. This section should be as
complete as the Lower Ft. Union and Lance sections located
at the Madden Field. This is analogous to the published 2-D
seismic lines that were utilized in the original Cave Gulch
field seismic interpretation.
Philp-Knapp
No. 1-18 Proposal
The Philp-Knapp lease
is located in Sections 7, 13, &18-T39N-R90-91W within
the Madden Unit Area. Structural mapping utilizing
subsurface data at the top of the Lance indicates that the
proposed location will test a series of Lower Ft. Union and
Lance sands on the north flank of the Madden Unit. The Lower
Ft. Union and Lance Formations are gas saturated yet only
sparsely tested in this area of the unit. Review of the
available seismic data in the area indicates the presence of
possible deep-seated faulting en echelon to the Madden
anticline and primary Owl Creek thrust fault. Review of
aerial photomap data indicates a deep-seated structural
feature north of the Shelter No. 1-19.
Correlation of
individual sands in the fluvial section of the Lower Ft.
Union and Lance is impossible even at 40-acre spacing. Gas
recoveries indicate the presence of a much larger gas
reservoir. Natural fractures associated with east-west
trending faults and vertical and lateral variations in
sandstone deposition have compartmentalized a large gas
accumulation along the north flank of the Madden
anticline.
Monsanto drilled the
Shelter 1-19, NWNW-19-T39N-R90W, on February 5, 1979 and
completed the test March 31, 1980 from perforations in the
Shannon at 18,790-19,253'. The well was fraced with
229,000 gal water, 250,000 # sand, and flowed 1,200 MCFGPD
and produced 56,680 MCFG + 7,881 BW. Last production from
the well occurred in 1980.
During the late 1970's
and early 1980's the Shannon sands of the Cody Formation
were the primary targets at Madden. Over the past several
years, the emphasis has focused more on the Lower Ft. Union
sands, the Lance, and the deeper Madison
Formation.
Analysis of the
Density-Neutron log indicates that numerous gas-saturated
sands are behind pipe. The Shelter No. 1-19 logged 61 pay
sands in the Lower Ft. Union and Lance identified by gas
effect occurring on the Density-Neutron log combined with an
8% porosity cut-off. Thickness of net pay sands in the
wellbore totaled 1090'. Thickness of individual sand bodies
ranged from 4-54' and averaged almost 18' per unit. Porosity
in the sands ranged from 8-13%, with a few sands in the
14-16% range. Mud log gas shows over these same intervals
indicate a gas saturated section.
Drilling of the
Shelter No. 1-19 took more than a year to reach total depth.
Sands of the Lower Ft. Union and Lance Formations were
likely damaged by the length of time the drilling fluids
were on the formation. Wells were completed with sand and
water fracs during this era resulting in additional damage
to the reservoir. Today, wells are drilled in 3-4 weeks and
completed with inert gas foam fracs and sand.
Burlington Resources
has completed the MDU No. 8-23, SWNE-23-T39N-R91W, in June
2003, flowing naturally at 3.3 MMCFGPD from perforations at
6882-90', 6908-12', and 6926-30'. These sands directly
underlie the Waltman shale that has been the target of
Burlington's most recent activity. Log calculated porosities
are in the 14-16% range. This well is arguably the best well
in Burlington's 50 well shallow Madden Unit drilling
program.
Burlington Resources
recompleted the Mesa-Federal No. 1-14, SWNW-14-T39N-R91W in
several zones within the Lance below 15,000'. The well
flowed 1060 MCFGPD + 53 BWPD from Lance perforations at
15,010-020', 15,072-082', 15,168-180', 15,250-282'. This
well is about one mile west, and it is approximately 1000'
structurally low to our proposed location. The Mesa Federal
was originally drilled to the Cody in November 1980 and
completed for 60 MCFGPD from perforations at 20,048-20,212'.
There was no known production reported from the Cody.
Petrophysical analysis of the Density-Neutron log indicate
978' gas pay in 55 zones in the Lower Ft. Union and Lance
Formations.
Double Eagle Petroleum
has completed their Allen Deep No. 1, located
SENW-26-T39N-R90W, for 3.5 MMCFGPD from the Lower Ft. Union
Formation. The well was drilled to a total depth of 12,150'.
High pipeline pressures of over 1,100 psi had initially
restricted production rates. Cumulative production has
totaled about 500 MMCFG from perforations in thin Lance
sands. This extends the Lower Fort Union production
one mile north of Madden Fields previously known
limits.
Double Eagle has
offset the Allen Deep No. 1 with the Lloyd No. 1-26,
NWNE-26-T39N-R90W, drilled to total depth of 7225' on August
5, 2000. Mud log shows in sands of the Lower Ft. Union
immediately underlying the base of the Waltman shale
indicate productive potential. This well is waiting on a
frac.
The Barrick No. 1-24
Leonard, located NWNW-24-39N-90W, was completed in January
1984 flowing 3881 MCFGPD from perforations at
14,628-14,688'. Cumulative production totaled 867 BO +
538,156 MCFG + 2,987 BW. Date of last production was
mid-1997 while the well was being operated by KCS Mountain
resources. This well had numerous mud log gas shows, flowed
gas during drillstem testing, and exhibited Density-Neutron
log gas effect throughout several zones in the Lance and
Fort Union Formations. It is important to note that this
test, if drilled using current drilling and mud engineering
technologies, could be drilled in less time than the 110
days required in 1984. The numerous zones having similar
petrophysical characteristics as the Barrett Resources Cave
Gulch discovery could be completed using state of the art
frac technologies resulting in large volume gas production.
Double Eagle acquired the Leonard No. 1-24 and flowed gas at
rates of more than 2 MMCFGPD from 13,300' during June 2000
workover.
A drillstem test of
the Lower Ft. Union in the Leonard No. 1-24 from
7,128-7,229' flowed gas at a rate of 2,272 MCFGPD. This
indicates a gas column of more than 1500' ranging more than
8 miles long, at least as far west as the Mesa-Federal No.
1-14, and without an identifiable gas-water
contact.
Several key wells also
indicate the potential of the Madden anticline off what is
believed to be the anticlinal axis.
The Pure Oil, Badwater
Unit No. 1, located NENW-35-39N-89W was completed in
November 1957 flowing 5500 MCFGPD on 1/2" choke from
perforations at 15,216-16,472'. Unocal relogged the well
with a TDT tool 20 years after the initial test. The TDT
tool logged 22 zones displaying gas effect between
12,300-14,150'.
The Moncrief Badwater
Creek No. 1, located SWNE-12-38N-89W, drilled by Moncrief in
1991, was originally set up as a 24,500' Madison test. This
test is located about 12 miles east of our proposed location
on the easterly plunging nose of the Madden anticline. Due
to the unexpected thickening of the upper formations,
drilling operations ceased at 20,080' in the Cody Shale.
Production casing was run to a plug back depth of 14,600'.
Completion data from March 30, 1991 reports an IP of 1,790
MCFGPD from perforations at 13,926-14,022. No frac treatment
has been reported. This well is reported to have had 26
zones exhibiting gas effect on the Density-Neutron log
between the depths of 11,150 and 14, 050'.
Birdseye
Creek Prospect
The Birdseye Creek
Prospect is characterized as a subthrust Lower Cretaceous
and Mississippian Madison plays. The play is set up by the
CIG Exploration No. 1-4-39-94, located NWNE-4-T39N-R94W. The
well was spudded October 1978 and drilled to a total depth
of 17,550' in the Cody. A drillstem test from 15,575-886'
flowed gas to surface in 206 minutes at 1300 MCFGPD. Times
and pressures are described as: op 426, SI 137, op 71, SI
361, 1200' WC, FP: 9,146-11,326, 5557-5209, SIP: 8254-8254,
HP: 12,252-12,380. A drillstem test from 15,637-886'
flowed gas to surface at 1,100 MCFGPD. Dipmeter analysis of
this well indicates 45-50 degree south dip beneath the
thrust cut at about 6140'. The play is fortuitously
located in a crestal position on an anticlinal feature
bounded by the CIG well on the south flank and postulated
rollover in the Owl Creek thrust. Mapping of the air-mag
indicates a basement structure approximately 2 miles wide by
four miles long. Total depth for a Mississippian test will
be in the 17,500' range. The Birdseye Creek area has
multi-TCF Madison potential at moderate drilling
depths.
Gas
Marketing
Lost Creek Gathering
Co., L.L.C., formed by Burlington Resources, Inc. has
completed construction a 127-mile, 24-inch diameter natural
gas gathering system. The pipeline is expected to be able to
deliver an additional 120 MMCFGPD from the Madden Field area
into the Colorado Interstate GasCo and Wyoming Interstate
GasCo pipelines without compression and approximately 275
MMCFGPD with compression. The completion of these facilities
has enhanced gas-marketing capabilities out of the
area. The completion of the Kern River expansion and
the approval of the Cheyenne Plains project to move gas
eastward has resulted in a closure of the Rockies basis
differential and overall higher gas prices.
Summary
Improvements in
drilling and completion technologies have been the primary
reason Burlington Resources and Barrett Resources has been
successful in the prospect area. The universal use of
downhole motors has been a major advantage. The current
drilling plan drills to total depth at 15.000' in the Lance
in 65 days, where in the past, the Lance was subjected to
drilling fluids for 3 to 4 months during the drilling of a
deeper test, causing almost irreversible formation damage.
The use of flow through composite plugs allows gas to flow
up the wellbore while testing additional zones without
having to kill the well with water. These plugs are set with
wireline resulting in rigless completions, further reducing
costs.
Earlier 2-D seismic
surveys across the Madden anticline and the Owl Creek thrust
trend were next to impossible to accurately interpret due to
extreme velocity problems caused by thousands of feet of gas
saturated Upper Cretaceous and Tertiary Formations and by
velocity variations in the Waltman shale. The current state
of 3-D seismic technology has led to drilling successes in
this structural and stratigraphically complex area.
Burlington Resources has completed a 68 square mile 3-D
survey over the prospect area.
Development drilling
in the Madden Field continues to target potential pays from
6000' to the Madison at 25,000'. Advances in drilling
technologies have reduced well costs. Modern 3-D seismic
enhances reliability of interpretation resulting in
increased exploratory success. These factors make the area
an attractive development play with ultimate reserves
ranging to 220.4 BCFG and 1 MMB condensate.
Formation of
the Noble Ridge Unit is a key strategy as it allows us
to:
1) Manage and
ultimately maintain our lease position
2) Control the pace of
Lance development drilling as Unit operator
3) Acquire appropriate
velocity, geological, and geophysical data to further define
a subthrust Madison drilling location.
Prospects
Click
Baxter to see - Baxter
Ranch - San Joaquin Basin, Kings County, California
Click
Bluff Bench to see - Southern
Paradox Basin - Bluff Bench - Aneth Area, San Juan County,
Utah
Click
Madden to see - Philp
- Knapp Lease Madden Unit, Fremont County,
Wyoming
Click Owl
Creek to see - Owl
Creek Thrust Trend - Wind River Basin, Fremont County,
Wyoming
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