Geology From 1991

Plainview Prospect T2S R70W

Jefferson Co., Colorado

February 25, 1991 . R. Randy Ray Geologist/Geophysicist Copy No. 10

1

Table of Contents Page Executive Summary

.

4

Introduction

.

4

Regional Structure

.

5

Golden Thrust Fault

.

5

Lyons Sandstone

.

7

.

8

Niobrara Chalk

.

9

Thermal Maturity

. 10

Conclusions

.

Dakota and Muddy

References

"J" Sandstones

.......................................................

Appendix I - Summary of P-Lyons Fields Appendix

II - Oil Seeps

2

10

11

.

15

.

16

Illustrations List of Fi2;ures Denver Basin after Tainter, 1984 Generalized stratigraphic column after Leroy, 1955 Generalized tectonic map after Warner, 1980 Golden Fault Structural Models after Domoracki, 1986 Geologic cross-section at Soda Lakes, Berg, 1962 Golden Fault Seismic Line - Final Stack, Domoracki, 1986 Interpreted Golden Fault Seismic Line - Migrated Modified from Domoracki, 1986, Interpreted by R.R. Ray State Highway 72 - Seismic Line - Final Stack from Domoracki, 1986 Interpreted State Highway 72 - Seismic Line - Final Stack from Domoracki, 1986, Interpreted by R.R. Ray Typical electric log Pierce Field Area and geologic cross-section after Sonnenberg, 1984 "Pierce-Black Hollow" right-wrench zone after Stone, 1985 Seismic structure map on the Lyons Formation of the Pierce-Black Hollow-New Windsor oil field complex, Weld Co., Colorado after Stone, 1985 East-West electric log section from Eldorado Springs outcrop to east Side of Wattenberg Field after Weimer & Sonnenberg, 1989 Index map of thermally mature and oil productive Niobrara formation after Rice, 1984 Geothermal gradients in the northern portion of Denver Basin after Weimer & Sonnenberg, 1989 Photograph of fractured Ft. Hayes Limestone in outcrop north of Morrison, Co.

1) 2)

3) 4) 5) 6)

7) 8)

9) 10) 11) 12)

13) 14) 15) 16)

Plates Plate Plate Plate Plate Plate Plate

1 - Structural Cross-section A-A' 2 - Geologic Map, I" = 2000' 3 - Stratigraphic Well-log Cross-section E-E' 4 - Muddy "J" Structure Map, 1:100,000 5 - Fox Hills Structure Map, 1:100,000 6 - Prospect Leases, I" = 2000' showing pipelines and proposed seismic program

3

Plainview Prospect T2S R70W

Jefferson County, Colorado

Executive Summary Plainview Oil and Gas holds leases on a prospect 15 miles west of the center of downtown Denver. It is a combination gas and oil prospect located very close to market. An 8 inch intrastate pipeline passes across the lease. Plainview Prospect is a structural trap formed at the intersection of regional fault trends along the Front Range. The eastward thrusted Golden Fault is the dominant structural element and hides the underlying basinal structure. It overlaps the Idaho Springs-Ralston shear zone which formed the Colorado Mineral belt and creates a regional fracture trend in the Denver Basin. Potential primary productive zones include fractured Niobrara chalks, Dakota Sandstones and Lyons Sandstones. Secondary productive zones may include the Terry, Hygiene and Muddy-J Sandstones. Potential reserves of up to 10 million barrels of oil are possible based on analog fields. Further seismic definition of the prospect will be needed to confirm the presence and size of a structure underneath the northern extension of the Golden Fault. An acreage block of 3088 acres is presently held over the prospect and could be enlarged after seismic definition. Introduction Plainview Oil and Gas acquired leases over an area that is attractive for oil and gas exploration. The acreage is located northwest of Denver, between the towns of Golden and Boulder, along the Colorado Front Range (figs. 1 & 3). The acreage lies at the western margin of the Denver Basin as it abutts the structurally uplifted Front Range. The Denver Basin covers most of the eastern half of Colorado with the deepest part of the basin lying next to the mountains near Denver (fig. 1). Because of its long producing history, the stratigraphy of the basin is well known, both from subsurface and outcrop control. A diagrammatic, generalized stratigraphic section prepared by Leroy, 1955, is shown in figure 2. Additional information has been added which helps clarify the following discussions.

4

the

The northern extent of the Golden Fault is unclear from outcrop information. In outcrop, the Paleozoic and Mesozoic rocks continue to have steep east dip all along the mountain front. However, at Superior the vertical to 60° E dipping beds at the Fox Hills sandstone flatten out and head off to the northeast. The change in trend is coincident with the projection of the Idaho Springs-Ralston shear zone as it emerges from the mountain front. The Superior area has several NE trending faults exposed in outcrop. The area has been mined for coal in the Laramie and Fox Hills zones since the late 1800's. The faulting has been interpreted to be listric normal faults caused by sediment loading associated with prograding Fox Hills deltas (Weimer, 1973; Davis, 1974; Davis, 1985). This is probably a secondary structure created by the underlying wrenching associated with the Idaho Springs-Ralston shear zone. New seismic data acquired by the Colorado School of Mines (Domoracki, 1986) helps to illustrate the geometry of the Golden fault as a low angle (30°) thrust fault (fig. 5). Displacement on the Precambrian surface is about 10,000 ft. Using this new model of the faulting, it becomes clear that the Golden Thrust Fault is a low angle thrust which is losing throw and dying out to the north where it is overtaken by the wrenching associated with the Idaho Springs-Ralston shear zone. The intersection of these trends is an excellent area to generate structural folding. faulting and fracturing. Even though the seismic evidence of the Golden fault zone is clear, the resolution of the footwall structure is more difficult (fig. 6). There is a large reflection time distortion caused by overthrusted, high velocity Precambrian rocks. This causes velocity pull-up which makes the reflections appear to be rising to the west. When properly corrected to depth, the basinal dips would be flat lying to slightly eastward dipping. With this new model in mind, the Colorado School of Mines seismic line down Highway 72 can be interpreted. This data was shot as 12 fold vibroseis in 1977 (Davis and Young, 1977), but has been reprocessed by Domoracki, 1986 (fig. 7 & 8). When a 30° thrust fault is placed on the section, it becomes clear that reflections underneath the fault are probably associated with fault blocks in the basin. Of particular interest is an arching reflection just underlying the leading edge of the thrust which appears to be a high fault block. At this position, there is not much velocity pull-up created since the thrust carries Pierre shale over the Pierre shale in the basin. Velocity pull-up will begin to increase west of SP 15 where the Niobrara limestone is present in the overthrust block (see Plate 1). Lvons Sandstone The Permian Lyons Sandstone is one of the primary objectives in the Plainview Prospect since it is an oil producing zone in several large fields. The outcrop of Lyons Sandstone in the Boulder to Morrison area has two major facies which interfinger with each other. The first is the white to red, fine to medium grained, cross-stratified, quartzose sandstone recognized as eolian dunes at the type section in Lyons, Colorado.

6

number

As previously discussed, the seismic indicates a basement fault block on the Plainview acreage. This basement structure could be created by the wrench faulting of the Idaho Springs-Ralston shear zone analogous to the Pierce or Black Hollow fields. Based on outcrop and subsurface control, the Lyons Sandstone is present and could be trapped in a low relief anticline under the leading edge of the Golden Fault. Dakota and Muddv "J" Sandstones Potential for an extension of the Superior Gas Field is possible in the prospect area. Production is primarily oil and wet gas-condensate from Dakota channel sandstones (see stratigraphic cross-section E-E'). The Muddy "J" Sandstone is generally thin and tight, but does produce in a couple of the wells. The Dakota interval is comprised of two to four channel sandstones in this area. Based on correlation to outcrop three miles to the west, the lower channel is Lytle Sandstone. It generally is not productive, testing wet. The middle channel is the Plainview Sandstone and it appears to be the most continuous channel across the prospect area. It is productive and reaches a maximum of over 60 feet thick in wells closest to the Plainview Prospect area. The upper most channel is the El Dorado Springs Sandstone and it is also productive. It appears to be pinching out to the south across the prospect area. Gas production from the Dakota channels is at a rate of 250-650 MCFPD per well. The sandstones completions generally include fracing and acidizing treatments. The wells closest to the prospect are all shut in and have no completion test information. The Muddy "J" Sandstone is productive to the north and south. Wattenberg Field with reserves in the order of 1 TCFG from the Muddy "J" Sandstone is about 15 miles to the northeast. To the southeast, the Teton Energy Co. Church Estate #22-1 well tested oil and gas from the "J", even though it is currently shut-in. Most Muddy "J" production is classed as from stratigraphic traps, but subtle paleo-structure and unconformities have also controlled the petroleum accumulations (Weimer and Sonnenberg, 1989). A structure map on the Muddy "J" Sandstone (Plate 4) indicates a prominent NW-SE trending nose on the south end of Superior Field. The nosing may be related to a NWSE trending fault as seen in the Precambrian outcrop. The structural discontinuity is shown in the shallow Fox Hills structure map also (Plate 5). A second NW-SE trending structural nose is also contoured by Van Horn, 1976, through the Teton Energy Church Estate #22-1 well. This structural trend could be part of the trapping mechanism for "J" in the well, even though it is structurally much lower than wells in the Superior Field. This structural trend may also be indicating a basement flexural trend that would create closure under the Golden Thrust.

8

Niobrara Chalk The Cretaceous age Niobrara Chalk interval is the other primary objective in the Plainview Prospect. It is an attractive oil and gas producing target when developed using horizontal drill holes to intersect vertical fractures. The brittle chalks in the Niobrara have a tendency to naturally fracture due to compaction and burial, as well as local tectonics. As articulated in the Ree:ional Structure and Golden Thrust Fault sections, preceding, the Idaho Springs-Ralston SW-NE trending basement shear zone intersects the north-south trending Golden Thrust Fault underneath the Plainview Prospect acreage block. This should enhance the fracturing at depth. Figure 16 illustrates the intersecting vertical fracture pattern of the Fort Hayes Limestone member of the Niobrara as exposed in outcrop north of Morrison (Sec. 26, T4S, R70W). The outcrop dips about 45° east and shows prominent north trending fractures spaced on average about one foot apart. These are intersected by cross fractures trending NW-SE spaced every 2-6 feet apart. Oil produced from the Niobrara chalks is sourced from the surrounding organicallyrich shales. The shales, like the chalks, were deposited in shallow to deep marine environments. When thermally mature, the Niobrara shales generate hydrocarbons that migrate into the fractured chalks. The Plainview prospect is in the thermally mature, oil-generating part of the Denver Basin (Tainter, 1982) and is in the area where wells produce oil and wet gas condensate from the Niobrara (Rice, 1985). (see fig. 14) Weimer and Sonnenberg, 1989, has noted higher geothermal gradients associated with an extension of the Colorado Mineral Belt trend (fig. 15). The deep burial depths and higher heat flow associated with the Idaho Springs-Ralston shear zone create thermally mature rocks in the Niobrara. The Soda Lakes oil field produced 13,000 BO and flared untold quantities of associated gas after its discovery in 1955. It was trapped in a structure along the Golden Thrust similar to the Plainview Prospect. The S.D. Johnson #' Lillie Pallaoro well (see Plate 3) indicates the production was from the Fort Haves Limestone interval in the basal Niobrara chalk formation. Immediately adjacent to the Plainview Prospect, the vertically drilled Martin Exploration Carrucci #1-33 well blew out three times; twice while drilling the top 120 feet interval in the Niobrara and once while drilling the basal Fort Hayes member. In addition, several wells (Sec. 13 & 25), in the Superior Field, produce from the Codell interval immediately underlying the Ft. Hayes Limestone. Electric logs run on wells in the vicinity show high electrical resistivities through a large part of the Niobrara formation. High resistivity readings like these correspond to producing areas in the Austin Chalk trend of south-central Texas (Hinds & Berg, 1990) and in the Silo Field of southwest Wyomine:.

9

Thermal Maturity The Plainview Prospect is located in a part of the Denver Basin which has oil and gas generating source rocks present (fig. 14). The mountain front between Boulder, Golden and Morrison lies juxtaposed to the deepest part of the Denver Basin (Tainter, 1982, fig.1). Marine shales of the Benton, Niobrara and Pierre formations are thermally mature and source hydrocarbons for oil production in the Denver Basin. Numerous oil seeps and shows have been reported (Stewart, 1955, see Appendix 11) along the Front Range. These are undoubtedly sourced from the shales underlying the Golden fault. The geometrical gradients mapped by Weimer and Sonnenberg, 1989 (fig. 15), indicate an extension of the Colorado Mineral Belt (Idaho Springs-Ralston Creek) trend into the basin across the Plainview Prospect. This should enhance oil generation and fracturing over the prospect. Conclusions The Plainview Prospect is a potential structural and stratigraphic trap in the deep portion of the Denver Basin. A review of available surface geology, well control, seismic and published articles shows it has potential for trapping petroleum in multiple reservoirs. It will require further seismic definition using modern high fold Vibroseis data. A program of about 13 miles should be acquired to detail the structural strike and dip orientations (see Plate 6). The lines should be designed to accommodate the expected structural complexity and still be able to get good data.

10

References Geologic Maps LeRoy, L.W., 1955, Summary of Surface Stratigraphy: in Field Conference on Geology of Front Range Foothills West of Denver; Rocky Mountain Association of Geologists, p. 15-24. Scott, G.R. and Cobban, W.A., 1965, Geologic and Biostratigraphic Map of the Pierre Shale Between Jarre Creek and Loveland, Colorado: U.S. Geol. Survey Map 1-439 Scott, G.R., 1972, Geologic Map of the Morrison Quadrangle, Jefferson County, Colorado: United States Geological Survey Map 1-790A, Scale 1:24,000 Sheridan, D.M., Maxwell, CH. And Albee, A.L., 1967, Geology and Uranium Deposits of the Ralston Buttes District, Jefferson County, Colorado: U.S. Geological Survey Prof. Paper Stewart, W.A., 1953, Structure and oil possibilities of the west flank of the Denver Basin north-central, Colorado: PhD thesis, Colorado School of Mines, T-777,121p. Stewart, W.A., 1955, Structure of the Foothills Area West of Denver, Colorado; in Field Conference Guidebook: Rocky Mountain Association of Geologists, p. 25-30. Van Horn, R., 1957, Bedrock Geology of the Golden Quadrangle, Colorado: U.S. Geological Survey Map GQ 103. Van Horn, R., 1972, Surfical and Bedrock Geologic Map of the Golden Quadrangle, Jefferson County, Colorado: U.S. Geological Survey Map 1-761-A Structure Berg, R.R., 1962a, Subsurface Interpretation of the Golden Fault at Soda Lakes, Jefferson County, Colorado: Am. Assoc. Petroleum Geologists Bull., v. 46, p. 704-707. Berg, R.R., 1962b, Mountain Flank Thrusting in Rocky Mountain Foreland, Wyoming and Colorado: Am. Assoc. Petroleum Geologists Bull., v. 46, n. 11, p. 2019-2032.

11

Davis, T.L., and Young, T.K., 1977, Seismic Investigation of the Colorado Front Range Zone of Flank Deformation Immediately North of Golden, Colorado; in Veal, H.K., ed., Exploration Frontiers in the Central and Southern Rockies: Rocky Mountain Association of Geologists, p. 77-88. Davis, T.L., 1985, Seismic Evidence of Tectonic Influence on Development of Cretaceous Listric Normal Faults, Boulder-Wattenberg-Greeley Area, Denver Basin, Colorado: The Mountain Geologist, v. 22, n. 2, p. 47-53. Gries, R, 1983, Oil and Gas Prospecting Beneath Precambrian Foreland Thrust Plates in Rocky Mountains: Am. Assoc. Petroleum Geologists Bull., v. 67, n. 1, p. 1-28. Stone, D.S., 1969, Wrench Faulting and Rocky Mountain Tectonics: The Mountain Geologist, v. 6, n. 2, p.67-79. Stone, D.S., 1985, Seismic profiles in the area of the Pierce and Black Hollow fields, Weld Co., Colorado: Seismic Exploration of the Rocky Mountain Region, RMAG & DGS 1985 Atlas, p. 79-87. Warner, L.A., 1980, The Colorado Lineament; in Kent, H.C. and Porter, K.W. eds., Colorado Geology: Rocky Mountain Association of Geologists, p. 11-21. Weimer, RJ., and Davis, T.L., 1977, Stratigraphic and Seismic Evidence for Late Cretaceous Growth Faulting, Denver Basin, Colorado; in Payton, C.E. ed., Seismic Stratigraphy - Applications to Hydrocarbon Exploration: American Association of Petroleum Geologists, Memoir 26, p. 277-300. Lyons Sandstone Blood, W.A., 1970, Upper Portion of the Fountain Formation and the Lyons Formation at Morrison, Colorado: Mtn. Geol., v. 7, no. 1, p.33-48. Dimelow, T.E., 1972, Stratigraphy and petrology, Lyons Sandstone, northeastern Colorado: Colo. Sch. Of Mines, unpub. M.S. thesis #1158. Levandowski, D.W., Kaley, M.E., Silverman, S.R, and Smalley, RG., 1973, Cementation in 'Lyons Sandstone and its role in oil accumulation, Denver, Basin, Colorado: Am. Assoc. Petroleum Geologists Bull., v. 57, p. 2217-2244.

12

Momper, J.A., 1963, Nomenclature, Lithofacies and Genesis of PermoPennsylvanian Rocks, Northern Denver Basin: Rocky Mountain Association Geologists Guidebook, 14th Ann. Field Conf., p. 41-67. Sonnenberg, S.A., 1984, The Pierce Field Structure: The Mtn. Geologist, v. 21, no. 1, Jan., 1984, p. 1-4. Thompson, W.O., 1949, Lyons Sandstone of Colorado Front Range: Am. Assoc. Petroleum Geologists Bull., v. 33, p. 52-72. Weimer, RJ., and Land, c.B., 1973, Lyons Formation (Permain), Jefferson County, Colorado: A Fluvial deposit: The Mountain Geologist, v. 9, Nos. 2-3, p. 289-297. Muddy J. Sandstone and Dakota Sandstone Weimer, RJ., and Sonnenberg, S.A., 1989, Sequence Stratigraphic Analysis of Muddy (J) Sandstone Reservoir, Wattenberg Field, Denver Basin, Colorado: Rocky Mountain Association of Geologists, 1989 Guidebook, p. 197-220. Niobrara Formation Smagala, T.M., Brown, C.A. and Nydegger, G.L., 1984, Log-derived indicator of thermal maturity, Niobrara Formation, Denver Basin, Colorado, Nebraska, Wyoming: Hydrocarbon Source Rocks of the Greater Rocky Mtn. Region, RMAG 1984 Guidebook, p. 355-363. Upper Cretaceous Weimer, RJ., 1973, Guide to Uppermost Cretaceous Stratigraphy, Central Front Range, Colorado: Deltaic Sedimentation, Growth Faulting and Early Laramie Crustal Movement: The Mountain Geologist, v. 10, no. 3, p. 53-97. Hinds, G.S. and Berg, RR, 1990, Estimating organic maturity from well logs, upper Cretaceous Austin Chalk, Texas Gulf Coast: Gulf Coast Assoc. Geol. Soc. Trans. - 40th Annual Mtg., p. 295-300.

13

Rice, D.D., 1989, Relation of hydrocarbon occurrence to thermal maturity of Organic matter in the Upper Cretaceous Niobrara Formation, eastern Denver Basin: Evidence of biogenic versus thermogenic origin of Hydrocarbons; in J. Woodward, F.F. Meissner and J.L. Clayton, eds., Hydrocarbon Source Rocks of the Greater Rocky Mountain Region, RMAG 1984 Guidebook, p. 365-368. Tainter, P.A., 1984, Stratigraphic and Paleostructural Controls on Hydrocarbon Migration in Cretaceous D and J Sandstones of the Denver Basin; in J. Woodward, F.F. Meissner and J.L. Clayton, eds., Hydrocarbon Source Rocks of the Greater Rocky Mountain Region, RMAG: p.330-354. Seismic Data Davis, T.L., 1974, Seismic Investigation of Late Cretaceous Faulting Along the East Flank of the Central Front Range, Colorado: Ph.D. thesis, Colorado School of Mines, T-1681, p. 65. Money, N.R, 1977, A Seismic Investigation of the North Golden Area, Jefferson County, Colorado: M.S. thesis, Colorado School of Mines, T-1849, p. 56. Nelson, K.J., 1977, A Reflection Seismic Investigation of the Golden Quadrangle Area, Jefferson County, Colorado: M.S. thesis, Colorado School of Mines, T-1990, p. 55. Ray, RR, Gries, R, and Babcock, J,W., 1983, Acoustic Velocities, Synthetic Seismograms, and Lithologies of Thrusted Precambrian Rocks, Rocky Mountain Foreland; in Lowell, J.D., ed., Conference on Rocky Mountain Foreland Basins and Uplifts: Rocky Mountain Association of Geologists, p. 125-135, Shuck, E.L., 1976, A Seismic Survey of the Ralston Area, Jefferson County, Colorado: M.S. thesis, Colorado School of Mines, T-1835, p. 45. Young, T.K., 1977, A Seismic Investigation of North and South Table Mountains Near Golden, Jefferson County, Colorado: M.S. thesis, Colorado School Of Mines, T-1947, p. 54.

14

43306,820 Cum. 11 15 141 316 Prod. No. Wells 23,421,112 10,648,846 11,207,343 896,621 327,321 12,816 2,717 5,939 12,548

Allliendix I

Field Nameof P-Lvons Fields Summary Status of Wells 11 PR

1 PR 14PR 1 PR o PR

1 S.I.

o PR o

PR

o PR

3 PR o PR

1 S.I.

30 PR, 2 S.I., 11 P&A All Wells Avg. Summary

535,092 BOIW ell

(Prod. Wells)

Field Name 3 15 1 3111 Black Hollow New Windsor Pierce Fort Collins Berthoud

No. Wells

Cum. Prod. 11,207,343 896,621 306,820 6,718 23,066,348 10,648,846

TOTALS

Producing Wells Avg.

752,944 BOIWELL

The two largest fields only Black Hollow & Pierce

25

21,856,186

Best Wells Avg. 874,971 BOIWELL

15

Appendix NOTE:

II This is a list of the oil seeps compiled by W. Alan Stewart, 1953, Structure and Oil Possibilities of the West Flank of the Denver Basin NorthCentral, Colorado: Colo. Sch. Mines Ph.D. Thesis #777, 121 p. My comments are added in brackets {*}. Oil seeps are plotted on Plate 5. Direct Indications

of Natural Hvdrocarbons

There are at least nine known occurrences of bituminous material in the foothills belt between the Ralston Reservoir and Dutch Creek. They consist of live oil seeps, dead oil residues, asphaltic sandstones, solid, brittle bitumens and shows in oil and water wells. An index map recording these localities is shown in Figure 19. The nature of the individual occurrences is discussed by index number below: Locality 1)

This locality is a live oil seep occurring in a gulch emptying into Golden Gate Canyon about 1-112 miles northwest of Golden. The seep occurs in metamorphic rocks and is located one-half mile west of the crystalline-sedimentary contact. The stream gravels in the bottom of the gulch are locally cemented by asphaltic residue. In summer, when the stream has nearly dried up, pockets of live, green, high-gravity oil accumulate in the gravels. It is believed that this oil rises through fractures in the crystallines from sedimentary rocks underthrust below them in the crystallines from sedimentary rocks underthrust below them in the footwall of the Golden Fault. {* Probably sourced from Cretaceous age rocks. Cretaceous oil is generally green, 44-48° F pour point.} 2) About 1-1/4 miles northeast of the locality, a live green oil seep was encountered when the Denver Fire Clay Company drove an adit into the Dakota sandstones to open up a fire clay seam (Van Tuyl, p. 744, 1932). 3) Van Tuyl (oral communication) reports an occurrence of high gravity petroleum in a water well drilled near the Fountain-Basement contact, west of Morrison and south of Red Rocks Park. 4) An oil show in the Dakota sandstone is recorded inn the driller's log of the Midas Oil and Gas Company, No.2 well, near Morrison in T5S, R69W (Barb, p. 134, 1946).

16

5)

Van Tuyl oral communication) states that a construction crew driving the pilot tunnel for the first tunnel on U.S. Highway 40 in Clear Creek Canyon, encountered a pocket of heavy, black, dead oil in the joints of the metamorphic rocks. This locality is about three-fourths of a mile west of the Fountain-Basement contact. {*Probably sourced by Paleozoic rocks. Paleozoic oil is generally black, 36-410 API gravity, paraffinic, 00 F pour point.} 6)

LeRoy (p. 31, 1946) describes occurrences of a black, brittle, bituminous substance in the shales and limestones of the basal Lykins formation in Glennon Canyon south of Morrison. 7)

LeRoy (p. 31, 1946) reports a similar occurrence in a limestone, 15 feet above the Lyons-Lykins contact on Ralston Creek. 8)

Heavy, black, brittle bituminous material was observed by Van Tuyl (personal communication) in a road cut near the parking lot behind the amphitheater at Red Rocks Park. This material was found in the four to five feet of the basal Fountain and in joints of the underlying crystallines. 9)

South of the Turkey Creek water gap in the Dakota hogback, there is an old quarry developed in an occurrence of bituminous sandstone at the top of the Dakota formation. An attempt was made once to extract the bitumen by a hot water or steam process. All of the foregoing occurrences are located in the hanging wall of the Golden Fault. The source of many of these hydrocarbons could be the 9,000 foot section of marine limestones and shales of the Benton, Niobrara and Pierce formations in the footwall of the fault. Trap possibilities are almost negligible in the upthrown block and commercial accumulations, if present, are expected on the downthrown side of the fault.

17

Oil and Gas ProspeCt

Plainview

Multiple Reservoirs) Nahlral F:ractured Setting

Denver Basin T2S R70W Jefferson CountY, Colorado The Plainview 17,18,

Oil and Gas Prospect

and 20 of Township

of 2,123 acres located

is comprised

2 South Range 70 West Jefferson

in Sections

County, Colorado.

The prospect

.

on the very Western Edge of the Denver Basin near the upJift of the Rocky Mountains. ' Basin has been and continues reservoirs.

The potential

Denver Basin.

to be a high!y productive

reservoirs

These reservoirs

age are also productive. encountering

are primarily

This prospect,

oil and gas reservoirs

fractures

greatly enhance

prospect

are based upon seismk

a1id then completed

reservoirs

reservoirs , locattd

only

:2

Cretaceous-age

1983.

high concentrations,

The seismic

data 'indi'cates

reservoirs

The Denver

that produce in the

but, reservoirs

of Permian

has a high probability

of natural

of the Church

c1osure, whereas

to other productive

miles southeast

~ndstones

C
and deeper structural

comparable

are ,simil,ar to the reservoirs

data and the location

lies

basin for both oil and gas iTom numerous

beC<.use of its ideal location,

with

the producing

in, January,

,

fractured

for thls prospect

8, 16,

fi-actures.

of

The natural

The key essentials

for this

#22;.1 well which was drilled structural

potential

the Church wen shows

in the Denver

Basin.

for highly

the presence

The Church

of

we\! is

of the prospect.

GEOLOGY The prospect

is locat~

city of Denver (Figure reservoirs

on the very western

1). The location of the prospect

are void of mobile water.

from the nearby giant Wattenberg will contain' hydrocarbons Structurally, Fault Denver

Basin.

without

this prospect

is a north-south

trending

The vertical

major fault 20ne is the Idaho zone.

The intersection

edge of the Denver Basi n, just northwest

is in an area of the basin where the deeper

It is a basin.centeredhydroC
Field.

Arty reservoir

significant

quantities

accumulation

that has sufficient

porosity

based on data and permeability

of water

Jies near the intersection thrust fault tha.~ separates

displacement

of two major fault trends. the Rocky

Mountain

Shear zone, a northeast

of these two faults is an idea! location

to generate

trending structural

The Golden

Uplift

of this fault is on the order of 6,000 feet.

Springs-Ra!ston

of the

&om the

The second

high angle shear folding, faulting

Plainview Oil and Gas ProspeCt Multiple Reservoirs, Natural ~ractured Setting Denver Basin T2S R70W Jefferson CountY, Colorado The Pla.inview Oil and G3s Prospect is comprised of 2,123 acres located in Sec~ioos 8, 16, 17, 18, and :2.0of Township 2 South Range 70 West Jefferson County, Colorado.

The prospect lies

.

on the very Western Edge of the Denver Basin near the uplift of the Rocky Mountains. '

The Denver

Basin has been and continues to be a highly productiye basin for both oil and gas from numerous reservoirs.

The potential reservoirs for this prospect are ,similar to the reservoirs that produce in the

Denver Basin. These reservoirs are primarily Cretaceous-age sandstones but, reserY'oirs of Permian age are also productive. encountering

This prospect, because of its ideal 1ocation, has a high probability of

oil and, gas reserY'oirs with high concentrations

of natural fractures.

fra.ctures greatly enhance the producing capabilities of the reservoirs.

The natural

The key essentials for this

prospect are based upon seismic data and the Iocation of the ,Church #22-1 weB which was drilled and then completed in January, 1983.

The seismic data'indi'cates

structural potential for highly

fractured reservoirs and deeper structural closure, whereas the Church wel1 shows the presence of reservoirs comparable to other productive reservoirs in the Denver Basin.

The Church well is

located only 2 miles southeast of the prospect. ,GEOLOGY The prospect is located on the very western edge of the Denver Basin, just northwest of the city of Denver (FigUre 1). The location of the prospect is in an area of the basin where the deeper reservoirs are void of mobile water. It is a basin~centeredhydrocarbon

accumulation based on data

from the nearby giant Wattenberg Field. My reservoir that has sufficient porosity and permeability

-

....

will contain' hydrocarbons without significant quantities of water StruCturally, this prospect lies near the intersection of two major fault trends.

The Golden

Fault is a north-south trending thrust fault that, separates the Rocky Mountain Uplift from the Denver Basin.

The vertical displacement of this fault is on the order of 6,000 feet.

major fault zone is the Idaho Springs-Ralston

The second

Shear zone, a northeast trending high angle shear

zone. The intersection of these two faults is an ideal1ocation to generate structural folding, faulting

and fracturing.

Figure 2 is a schematic of the location of these two faults along with other regional

features.

Figure 3 is a seismic line which shows the structure and potential reservoirs for this

prospect.

The deeper Cretaceous reservoirs in the footwall (subthrust block of the Golden fault)

demonstrate

dip reversal against ·the fault, which may form structl.1ral or structural-stratigraphic

traps. However, structural closure is not necessary for the Cretaceous reservoirs to be productive. Also shown is a "triangular"

zone that is believed to be highly fractured and could c.ontain an

unusually large amount of hydrocarbons.

This zone is comprised of Pierre Shale, which is the

major source bed for the deeper Cretaceous reservoirs, and it is oil productive in several areas of the basin.

RESER YOIRS Lvons Sandstone The Lyons Sandstone is the deepest potential reservoir. hydrocarbons

This reservoir has produced

from several anticlinal structures along the west flank of the basin.

The geologic

setting of this prospect is very simila.r to that at Black Hollow Field. To date the Lyons has not been a large contributor to the overall hydrocarbon production in the Denver Basin, however, the Black Hallow and Pierce Fields to the north in T8N and R66W have cumulative production of slightly less than 1,000,000 barrels of oil per well. If structural closure is present in the subthrust fault block of this prospect, the Lyons Sandstone could be a significant reservoir. Dakota Sandstones The Dakota begins just below the base of the J formation.

In the Church wel1 the first

Dakota Sandstone reservoir penetrated below the J Sandstone is the Plainview Sandstone (See Figure 4a). The Plainview Sandstone is approximately 2~one should be productive Sandstone.

in the Church well.

60 feet thick. Log analysis indicated this

Below the Plainview Sandstone

The Lytle Sandston~ is not considered productive in the Church well.

sandstone reservoirs are interpreted to be channel sandstone deposits.

is the Lytle Both of these

A third reservoir known in

the area as the El Dorado Springs Sandstone, which is above the Plainview Sandstone, is not present in the Church well. It has been interpreted that the El Dorado Springs Sandstone has been faulted out in the Church well but it should be present in most other locations in the prospect. The mudlog ITam the Church well had oil shows within the Plainview Sandstone. There were no drill-stem or· production tests of the Dakota reservoirs in the Church well.

The Dakota well.

According

interval was proven productive

to the Colorado

in the Superior Field 6 miles north of the Church

Oil and Gas Conservation

Commission

(COGCC)

records

a total

of 6 wells in the Superior

Field were completed

These

an average of only 1,100 barrels of oil and 79.0 mil1ion cubic feet of ga$

six wells produced

due to inadequate

fracture

treatments

1980' s. The log characteristics

in the early

are similar

to the wells in the Superior

producing

hydrocarbons,

completion

pra.ctices currently

especially

Field, and therefore, considering

utilized.

and rracture

only in the Dakota interval during the early 1980' s.

resistivity

profiles,

computed

porosity and water saturation

the

In addition

indications)

of the Church well

the Church well should

advancement

to comparing

of the Church

of fracture

be capabJe of

technoJogy

the log characteristics

and

(thickness,

well with welts in the Superior

Field,

values ITom log data displayed very similar results.

"J" Sandstone The J Sandstone

is the most prolific

Sandstone

reservoirs

formation

(See Figures 4a and 4b).

indicated

are at a depth ,of approximately

32 Teet of hydrocarbon

can have three producing channel

intervals,

bearing

shaly deltaic sandstone,

sandstones.

known

in the Denver

exceeds 50 feet of thickness.

as the J1, J2 and J3 reservoirs,

The J

Log analysis

as a valley fill channel

is the poorer of the three reservoirs.

interval

The J1 is generally sandstone.

within the 11 and 12 sections.

are located

Basin.

In the Denver Basin the J Sandstone

The 12 is identified

sandstones

formation

9,500 feet or about 400 feet below the Codell

The gross interval

bearing

or barrier bar sandstone.

of hydrocarbon

producing

a

The 32 feet

The 13 reservoir,

The J3 is not present

a

in the Church

#22-1 well. The J1 Sandstone The Monaghan property,

is credited

with having

State #1-16 well located within the boundary

approximately

30 miles east of this prospect,

and 12 billion cubic feet of gas.

More recently

wells

boundary.

drilled

established

within

the airport

by earlier fields, such as Radar,

onto the DIA property. .prospect

From

of Denver International

produced

more than 250,000

Basin.

Airport (DlA) barrels of oil

the J2 interval has also been a primary reservoir

These

newer

on the eastern

DlA the J2 val1ey-fill

wells

continued

boundary

sequence

a development

of DIA extending

continues

westward

in

trend

westward through

the

area, Shown

Ambush

the most prolific gas well in the Denver

in Figure

5 is a well Jog cross~section

#23-11 weJllocated

wi"thi'n the boundary

ofDIA.

from the Church This ~ew.DIA

#22-1 weB to the West well, completed

in 1998,

>.>

has a comparable 11 and J2 section. This new Ambush #23·11 well has already produced more than 60,000 barrels of oil and 400 million cubic feet of gas. The Church #22-1 well was originally completed in January 1983. A gross interval of 48 feet was perforated with a total of 11 perforations in the J1 and J2 reservoirs. By today' s standards t~is was an inadequate

number of perforations

to cover an interval of this thickness.

perforations were fracture treated with 45,00 gallons of 2% KCL water. not reflect the amount of sand used in the fracture treatment.

The

The COGCC records do

The well produced at a rate of 326

thousand cubic feet of gas per day, 10 barrels of oi] per day, and a water production rate of 75 barrels per day. The water production is believed to be fluid used in the fracture treatment. >This wel1 is located in an area of the Denver Basin where free water production does not exist.

The

records indicate the well was shut-in and was never connected to a gas sales Jine. In August 1984 a bottom-hole

pressure bomb was run in the well to a depth of 9,500 feet.

The pressure bomb

indicated a reservoir pressure of approximately 3,360 psig. A fluid level was indicated at a depth of approximately

8,850 feet (658 feet above the upper-most perforation).

The gradient of the fluid

appears to be that of oil and not of water. Considering the advancements of fracture technology and completion techniques used today versus the 1983 practices, it is highly likely tha.t the well could have produced at much higher rates. The J1 and J2 reservoirs should be low risk at the prospect location. Due to its location in the basin there should only be hydrocarbons if sufficient reservoir quality is found.

Also there is a

high probability of natural fractures at this location which would greatly enhance productivity. the prospect location the J is likely to have two benches.

At

The Jl and J2 reservoirs in the prospect

area should encounter a net thickness of approximately 20 feet for the 11 and J2 reservoirs. Niobrara.. F~.Hayes~and CodeJl The Niobrara/Ft. Hayes/Codell interval is approximately 340 feet thick, and it lies at a depth of approximately 8,800 feet. Of this total section the Niobrara is approximately 280 feet thick, the Ft. Hayes limestone is approximately 30 feet thick, and the Cadell is approximately 30 feet thick. The Niobrara formation is comprised mainly of brittle chalky limestone that has a tendency to fracture. This prospect is located in an area of high tectonic activity, and therefore, the Niobrara has :ahigh probability of being naturally fractured. The Ft. Hayes is a limest~ne that is usually natura,l[y> >fTactured, and numerous wells dri11ed in the Denver Basin have recorded oil shows iTom this formation. The Codell reservoir located just below the F( Hayes limestone is a shaly sandstone that

generally requires hydraulic fracture treatments in order to produce. Figure 4b shows a log section over this interval.

It is quite common for wens to be completed in all three intervals with the

production commingled. The combination of these reservoirs is very prolific in the Denver Basin.

The Wattenberg

Field located in the vicinity of the city of Greeley, Colorado and northeast of the Church #22-1 well, has produced ITom these zones in 100's of we!1s. Also, these reservoirs have produced in the Superior Field approximately 6 miles north of the Church well location In southeast

Wyoming

the Silo Field produ'ces. from t~e Niobrara

horizontal and vertical weIls were utilized in completions.

formation.

Both

This prospect location is in an idea!

location for natural fractures to occur within this zone, which would greatly enhance production , capability. At the base of the Niobrara is the 30 foot thick Ft. Hayes limestone. has not been a large contributor to the regions' oil and gas production.

To date the Ft. Hayes

But the geologic setting of

th1S prospect is ,similar to the structural trap found in the Lillie Pal1aoro #1 well in Section 6 T5S R69W.

This wen, disco~ered in 1955, produced more than 13,000 barrels of

011

and a significant

but unknown amount of associated gas. ' The Codel1 sandstone is located just below the Ft. Hayes limestone. thick sandstone that generally requires hydrauJic fracturing to produce.

It is a shaley 30 foot

The Codell has been the

main recompletion candidate for"many of th,e J wells dri!1ed in the Denver Basin. For this prospect these zones are considered secondary objec.tives but should provide supplemental reserves. The Church #22-1 well has comparable reservoir characteristics in this interval compared to ,

other wells in the area that have produced iTom these reservoirs. Also, it is in an area very favorable' for natural fracturing, which would enhance production ca.pability. Pierre Shale The Pierre Shale is a.n organically rich shaie that is thought to be the main source rock of hydroc.3rbons fot'the deeper Cretaceous reservoirs. conventional hydr0c.:u:bon res~oir

The Pierre Shale is not normally considered a

.. However, the unique location of this prospect has enhanced

the possibility of a very thick., natural1y fractured section of the Pierre Shale.

If this formation

proves to be highly tracrured as indicated by seismic data, trapped hydrocarbon reserves could be more than 75 million barrels of oil under the prospect area. Even though the probability for this large reserve is not certain, it is a very attractive section that must be driHed prior to reaching the

deeper

CretaC-..""0us reservoirs.

immediate

It is a zone

with

an

extremely

hig~

which

deserv'es

reserves

and cash

potentia.l

attention.

ECONOJv11CS Three economic Oow from al1 potential reserves

and cash

productive

Dakota

reservoirs

flows

area.

Case

reservoirs,

following

scenarios

were run for this prospect. for 50 productive

from the J, Dakota C projected

The economic

table summarizes

wells within the prospect

and Lyons

reserves

Ca.se A projected

reservoirs

and cash £lows

ana.

for 2S productive

for a single

Case B projected wells

well completed

wltrun in the

J

the and

output for the tnree cases is sr.o'Wn in Fig\li'es 6a, 6b, and 6c.· The

the economic

proje.ctions

for the 3 cases.

.

I. 1 59 200 2 97 Reservoirs 14,700 575 850 Reserves Cash 25 Reserves· Flow OfWe11s 42.000 Code!lINiobrara 50 Gross 98,700 Dollars) 25 I Lvons, JG2..s Dakota., Lyons 36,800 I Pierre., 258,300 25.500 (Thousand .131.600 (Thousand (Million (Thousand Barrels) J, Dakota, Do11ars) J,Discounted Dakota SCFJ

Gross

I I

Oil

MARKETS When the Church the gas production.

Currently,

natura! gas and is therefore market

remains

strong

#22-1 weB was dri!1ed an electrical

a r~dy

market

due to the refineries

there was no convenient

generating

pipeline

at that time for

plant is being built nearby which will burn

for the ga.s production

from the prospect we!!.

loc.ated just north of the city of Denver.

Authored by: Van Kirk & Associates' November,

2001

The

oil

Plainview Oil & Gas Inc. 8134 Logan Street

Phone: 303-289-6300

Denver, CO 80229..5840

E-mail:

L<;:.~[[email protected]!

December 30, 2005 POTENTIAL

IDGH PROBABILITY MJNIMUM RES.ERVES AND ECONOMICS ROCKY FLATS VENTURE JEFFERSON

COUNIT,

COLORADO

INTRODUCTION: Plainview Oil & Gas, Inc, (pOG!), has an acreage block in the Front Range Zone of Flank Deformation _.<\rea,located generally in the westerly portion ofT2S-R70 \V, 6th PM, Jefferson County, Colorado, that has the potential of encountering commercial accumulations of hydrocarbon liquids in up to seven (7) intervals from in the Pierre shale formation, down through the Lyons sandstone formation. This "Critique" only covers the possibility of a high probability occurrence of the basal Crmceous interval, known to be present in the subsurface under POGI's #1 State 16-4 suspended test we\!, located 460 feet snl and 460 feet ewl of Sec. 16, T2S-R70W, 6th P:M, Jefferson County, Colorado, from a depth of approximately 8,600 feet below ground level to a depth of approximately 9,550 feet below ground leveL

LOGIC: The "Logic" developed for use in this "Critique" contains two (2) components; the probabil1ty of the actual occurrence of the projected intervals in question in the basal Cretaceous formation (the subsurface rocks under the well site) and the probability of what kinds-offluid(s) may be in the potential void space that will be found within these reservoir intervals. An ancillary component in this discussion will be "how" these potential hydrocarbon reservoir fluids will react to depletion mechanisms involved in their subsequent production histories. POTENTIAL

FORMATION

AND RESERVOIR

INTERVAL

OCCURRENCES:

It is logical to predict, before the fact, that the gross, approximately one-thousand (1,000) .foot thick, basal Cretaceous formation, with up to five (5), projected void space hydrocarbon intervals, is present, based on the following three (3) bits of information: 1. An approximate thirty (30) mile long Electric Log Cross Section, from the Southwest portion of the Wattenberg Field, under the Rocky Flats Area in question and on to the Soda Lakes Field (discovered in 1952 - now abandoned), located southeast of Morrison, Colorado. 2. The physical, surface presence of this Formation, occurring in the"Hogback" outcrop, located about two (2) miles West of the POGI block of acreage. 3.. The reflective presence of this FOffilation in the DOE's, 2-D, dip-configured Seismic Line, traced in a southwest-northeast azimuth, directly across the POGI block of acreage. 1

..

The five (5), potential, high degree of occuning, reservoir intervals, within the basal Cretaceous formation and their projected gross ultimate hydrocarbon reserve, are as [ollows: Basal Cretaceous

Formation

(40 Acre Spacing)

Est. Oil Rec.

Zone Niobrara

chalk

Ft. Hays Is/Coden 55.

'T' sand Dakota (Plainview) ss. Lakota (Lytle) ss. Morrison formation

Est. Gas Rec.

(gr. bbls.)

(gr. mcf)

150,000 , .. 25,000 50,000 25,000

150,000 225,000 750,000 1,500,000 750,000

257,500

3,375,000

7,500

RTMD Totals

Est. Depth

"Footprint"

(GL meas.- ft.) . Silo Field, WY 8,600 Wattenberg Field 8,850

9,200 9,350 9,500 9,550 9,600

"

" "

NATURAL FRACTURING EFFECT(S) ON RESERVOlR PERFORMANCE: The POGI acreage block is located in the Front Range Zone of Flank. Deformation Area, at the intersection ofthe Golden Thrust Fault Complex with the Idaho Springs ~ Ralston Shear Zone (the Colorado Mineral Belt Trend). The Golden Thrust Fault Complex, primarily resulted from the tectonics involved with the Laramide Orogeny; ie; the Rocky Mountains, mountainbuilding process. At the approximate same time, the deeper, pre-Cambrian, Idaho Springs Ralston Shear Zone Feature was "r~uvenated", resulting in massive crustal movement in this

general Area., in three dimensions (lengthlwidthlheight).

This resulted in a well defined, fracture

zone trend area, in a "fairway" con:figuratio~ trending almost straight North-South, paralleling the ''toe''ofthe Mountain Front; a fTacture "location luxury", not often found in the "Oil Patch" in general! This directed, massive, natural fracture Continental Event, with attendant pattern, win have great positive effect on reservoir performance in. aJl of the potenttaJ hydrocarbon intervals expected to be penetrated in the deepening operation in POGI's #1 State 16-4 suspended test wel!. This massive and eX1ensive, natural fracturing will create, by its' very nature, permeabiJities that will be in the d 'Any's, with reservoir aniostropy's of considerably < J. This will advantageously affect gross ultimate recoveries and aHow for high, "steady state" hydrocarbon production rates for wells completed in these intervals. The reservoir mechanisms will be gas cap e.xpansion, gravity and solution gas drive(s). In this Area of the D/J Basin, there will be no free water productiqn_ Therefor, the productive scenario will allow for depletion of these hydrocarbon reserves to be programmed to a twenty (20) year productive life. 2

GENERAL ECONOMICS: All ofPOGl's properties are eighty (80)% NRI leases. POGI prescntly owns or controls 2,123.04 acres, more or less, in the Area. The Venture Property will be developed on forty (40) acre spacing. The mixed, associated and free gas production, will have ,an heating value ~hat will vary from 1100 to 1300 btu's.lst'd. cu. ft. and contain four point five (4.5) gpm of LPG products. In order to produce free hydrocarbon liquids from this Property win require the construction and installation of a cryogenic gasoline plant to produce a required "tailgate" product with a heating value of865 btu's/st'd. cu. ft., to be fungible with the gas in Xcel's, 6", town gas line market outlet. The "shrinkage factor" through the gasoline plant process will be fifteen (15) %. The gravity of the produced, free hydrocarbon liquids recovered at atmospheric conditions from the wells in this Project, will be 44° API, at sf d. condo Therefor: 2.123.04 40

=

53,075 productive forty (40) acre locations

all Recoveries: 257,500

=

(0.80) (53)

10,918,000

net gross bbls.

Plant "Tai1gate" Gas Recoveries: 3,375,000

(0.80) (0.85) (53)

= ·121,635,000

net gross mef.

LPG Product( s) Recoveries: 3,375,000

= 15,332,143

(0.80) (53) (4.5/42)

net gross bbls.

The net gross (to the WI) cash flow stream (assuming $60 oil and $) 0 gas, unescalated undiscounted and before all taxes and operating expenses), would be: Oil Revenues: 10,918,000

($60)

=

$

659,080,000

Plant "Tailgate Gas" Revenues: 12],635,000

1,2] 6,350,000

($10)

LPG Product(s) Revenues: 15,332,143

919.928.580

($60)

TOT ALS

=

The estimated gross capital costs to develop this total Venture Property may be: Gross Capital Costs of Producing Wens. complete: $1,500,000

=

(53)

$

79,500,000

Gross Capital Costs of Cryogenic Gasoline Plant: 6,000,000 Contingency

& Misc.

EXRenses (15%)::

TOTALS

$ 3

12.825.000 98,325,000

Therefor: Net Gross ROI;;;;;$ 2,795,358.580 $ 98,325,000

28.44/1

Assuming a twenty year productive life and "steady state" production rates, the net gross Pay-Out would be: $

= 255.94 days

98.325.000

Of

8.42 months

$ 2,795,358,580/7,305 The gross daily average production rates would be: Oil:

10.918.000/0.80 = 1,869 gr. bbls.lday 7,305 :Plant "Tailgate" Gas: = 20,814 gr. mcfi'day 12L635.000/0.80 7,305 LPG Products: 15,332.143/0.80 ~ 2,625 gr. bbls.lday 7,305 COMMENTS: It is interesting to note that there will be more LPG liquids recovered ITom the cryogenic gasoline Plant through-put gas flow stream, than will be produced as free oil production ITom all of the fifty three (53) productive wens in this "Critique", in tms Venture Area! This demonstrates the "cash cow" potential ofthis installation and further demonstrates the ''value'' of the UPRR railroad spur line that is contiguous to the driIl pad location for POGl's #1 State 16-4 test well. Also, Xce1's 6" Market line is located a.bout five-hundred (500) feet, North of the drill pad. The free oil production could either be trucked to Suncor's, 90,000 bbllday through-put Refinery, located about :fifteen (15) air miles, East of the location. or shipped by rail to Market. It should be remembered tMt this "Critique" does not take into account the fact that there a very excellent chance of obtaining major hydrocarbon reserves in the shallower PieITe shale interval (that will be penetrated in the deepening operation of testing the basal Cretaceous section) and in the deeper Permo-Pennsylvanian Age, Lyons sandstone formation, which occurs approximately eight-hundred (800) feet deeper, in the section; ie: at a RTVMD of 10,450 ft.

1S

. db~ /~

4

Sec. 20 ado

Exhibit "A" Plainview Oil & Gas; Inc. Rocky Flats Block T2S - R70W Jefferson County, Colorado

'.,

E/2 See,S NE/42,123.04 NE/4 640,00 Lease Lease May Preferential 2009 1,483,04 toSection August 12,21, Oil 2006 &Remarks gasRight lease, Rec, No,16 & (aU) Expires Acreage Description access OG 93/I140-S. Surface F0003599 State Lease &No. Sec. 18,restricted part ofNW/4

access denied F0876970 -Rec. Surface Document, No,

(2)

Area

Of Mature

Source

Rocks

C.1. = 500'

Figure 14. Structure

on J Sandstone at present, datum Is sea level.

after Tainter, 1984

POG fig. 1

0

.-Ea>c:

0

z

0 u HILLS lD LARAMIE o- .'-::7'~-==:,' FOX ERA AGE FORMATION DENVER-ARAPAHOE GREEN MOUNT AIN kda KL ~,,~",: ::,,',:,,:.', -:,',",:'',. ,', ) O'

Kfh LOWER w ARY :::-- TERTI ~1-1 o~

5 (j

~fJ~

.:-.

~._.

,_

t:\J

"

.•. - ............. •

O~

o

__

I/)

:J

o

PIERRE

W

u -< i-

u o N o \/1

uJ c::::

U

W

~

N lOB R A F',t\

.~-

120

, ','

rAK:~~~~

u o N o

u.:

Kb

J

o

E,5

--

---. ~ b>,

'.~":'

...

BENTON

DAKOTA CREEK L YKI SPL m Kd 1SNJrc PL 'yLYON

R,ALSTON MORRISON

JURASSIC

TRIASSIC

z <

z

<

>, ..J

>-

I/)

FOUNT AI N

PRECAMBRIAN

P after Leroy

£

1955

PRE C A

1~v1B

R I A i~ POG fig. 2

~

THE COLORADO

LINEAMENT

EXPLANATION

'BASE

OF"CENOZOIC

I ".~-:,;.-;-I "B A S E

OF

FOX

HI L L S \1

r:::=::J

-''L-1 PRE-UPPER

CRETACEOUS 1\

PRECAMBRIAN

~ OIL

FIELD

~ PRODUCTIVE

MINE

~ THRUST (TEETH

...",...-""""

HIGH

ANGLE

CD

DIABASE

®

SKIN

10

I

/ '1\ e

FAULT

"

DIKE

SHEAR

ZONE

MT.

SHEAR

ZONE

IDAHO RALSTON

o •

SIDE)

GULCH

(~MOOSE

o

-

FAULT ON UP

SPRINGSSHEAR

ZONE

I

" •"

.. -:- ~ 0 ~ 20 :1I, ,=0k E 10 100 / 1\ 3L 0

f

W

II

II

ED!:CEI: S C I, A

..

0

20

!

30 hi I

40

!

Figure 4. Generalized tectonic map of northeast Front Range foothills and adjacent Denver basin, Colorado. Compiled from various sources, Including Burbank and others (1935) •. Fisher (1946), Lovering and Goddard (1950), Hunter (1955), Parker (1961), Spencer (1961), Abbott (1970), Punongbayan (1972), Nesse (1977).

a ft er Warner, 1980 POG

fig. 3

+

EAST

pz

6000

APPROXIt0.4ATE

~a

Level

SCALE

1" '" 10.000'

E. jE~~~~~~_-_5_0_0_0 Figure 5. Golden fault structural models: A-Ziegler (1917, Fig. 6), through Golden; B-Stewart (1953, Plate 10), near Golden Gate Canyon, SP indicates shotpoint; CBirdsall (1956, Fig. 19), along Golden Gate Canyon; DBieber (1983, Fig. 5), near Ralston Creek; E-Money (1977, Fig. 14C), one mile north of Golden Gate Canyon. Ty=Tertiary; Mz=Mesozoic; Pz=Paleozoic; pC=Precambrian. after Domoracki, 1986

POG fig. 4

sw

JOHNSON TO 9655'

* I

-1-

NE

GREAT BASINS TO 9587'

,'.,

""""!-.

.•..

~~~:~1,1:~:~·;;:~j:;·;:·::-·.~,; .. I,"" ,~ ":''''::''''J'",,,,,:~?\:,~ __ : ,, _ '_ ''''.I , ••.•. ,\ r"'~"••. - - -\-, .. , ,.............•...... ~,\ -'-,,'"

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01

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Figure 6. Geologic cross-section Berg, 1962a, Fig. 4)

at Soda Lakes

(from

Triangle

Dakota

Lyons

...

__ [A:..J.

MF OF I..,

J

-~:,

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f(o

~.

.1.. I _~.

-\4

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,,

, I

] 1",

E

J

N

S E C C

N

o S

~

Figure ~7. Final stacK scale is compressed 2:1. of Golden fault; LB-line

~

Golden Gate Canyon. Horizontal MF-mountain front; GF-surface trace bend. after Domoracki, 1986

POG

fig. 6

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'I ••• ·1 -! I'X' ".'",1 '?.,J! -.-+':::-:' ",".-:'1" _'\1 ...,~. , ... ,J-,., J~; .. 'r~'i L."..L,. \"j-- \! ')",.1..,.-y.o."'" r~\ 'G"~ 'f\\ ..,.1-.,.-,, :,"j ;"; ..•.•d,:,' ..••. -;~. n-;!:' ',-:: 1j.~.J. ~I"": ,;'T' L," r~' MF 1'.GF _!1m" "i .'I~, 1""'I L"~I;cI'~,T.'rrl'L'11191 ~"·.·L.::1,1: I~ . t,· \ ,:., ~ (' f',:: •• ~'_r.'~_' /'.'7'~ LBI" '1":'I:,: j~"J 1111 .':"~";': 11'1 II:" .'~J.',( , ~: ~" ...'~.; 1~ ~ •. ~_ ·'··:~II".~Th~ (~ ..J"'.~; 1 _;.'..-1"-.:.

,t:, ~·-Y''r'·,t-Jr'· :~(' i'~.:

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Figure 18. Higrated stack Golden Gate Canyon. Higration with 80 ~ or stacking velocities. after Domoracki, 1986 Interpretation by R.R.Ray

POG

fig. 7

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." " 11'0 :tZ"'f,fU .:" "

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Figure 21. Final stacks - state Highway is' near 1: 1. after Domoracki, 1986

72.

Display

scale

'.

76° E dip Fox Hills outcrop

~

I!DI 3AI C!P G.

K nio'" Kd ak'"u

K pierre

P Iyons-.J"; T

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Plyons

l.l~i..'1 '.J l.' J.

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Figure 21. Final stacks - state Highway 72. Display scale is near 1: 1. after Domoracki, 1986. Interpretation by R.R.Ray. See also Plate 4.

A

NW

SP -11+

VERTICAL

~ .-

10 mv

z Mbr ~

=:*t> ~

poudra

Mbr

u.

~ w

-'-t-C -'12~ 0-

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Mbr

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o o

g

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z

PENN CARBONATES

~

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zw

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Figure

2.

1 '- ,,/ I

'-

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TR

LYONS SS? , \. ,. '\ ,. " " '" /' " /",.

Pumped 317 BOPD

/

I

p- '

'-

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I-

\ ~ •. ""

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-.c

000 n

-5000 It

oI

Typical electric log Pierce field area showing Lykins and Lyons Formations (California Co. # 1 Priddy, NW SW Sec. 23, T8N, R66W).

after Sonnenberg, 1984

""'\/ '\/rl'1

'-

TRUE SCALE PENII

i= /'\ PERM P-C BASEUENT

Pf 9201-9210,

-5000 ft

~I z FOUNT AIN FM

:;.

co~)

FM

~

~

N

-4000 ft

FM

Z >-

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,,

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CJ)

Forel/a

EXAGGERATION

:.:.:.LYON5 55:":-: :...:,- .

<x:

Crk

SE

-park creek La Member--

L YK\NS

Park

A'

8 to 1

Figure 5.

11.41

Structural cross section through Pierce structure. Note how subtle the structure is on true scale cross section.

: •• ••

WY.i ..•.......................-1-

41-

c o. ARE

A

~

of

F IG.12

[D

~

tn

2

9

t

DENVER

N I

o

I

10 20 30 40 50 I I I I I km

Figure 1: Index map showing area of Figure 2 from Stone, axis added. R,12 is the "Pierce,Black Hollow" right-wrench the "Colorado Mineral Belt." after Stone, 1985

o

l

10

20

I

I

30 1

mi

1969, Pl. 1, with New Windsor anticlinal zone, here called the Windsor Fault. R-ll

POG fig. 11

IS

Figure 2: Seismic structure map on the Lyons Formation of the Pierce-Black Hollow-New Windsor oil field complex, Weld County, Colorado. after Stone, 1985

POG fig.12

Weimer and Sonnenberg TETON ENERGY Sequences

Formations

Members

HE SE 13;

is - 70W

CONTINENT AL SE HE SW 5;

is - 69W

BRYAN

MARTIN SENE2;

NE NW 13;

1S-69W

PIERRE

is - 68W

-~-~ •..

-

4

5

Smok y

-

4

3

Hill

NIOBRARA

Ft. Hays

~ CARLILE

z a: o

Bridge Creek Ls.

J: Z

Hartland Sh.

a:

Lincoln Ls.

w w

3

c

x -

BENTONITE

5 >-

GRANEROS

2~~ 1 un:

TSa:~ LSr:

LYTLE Tn::::::MOWRY SKULL PLAINVIE\I MORRISON CREEK MUDDY (J)

TH

W AHEN

LH

Tn Lsr

\J

o

G)

(Q

-" c.v

Figure 15. East-west electric-log section from Eldorado Springs outcrop (modified from MacKenzie, 1971) to east side of Wattenberg Field (see Figure 3 for section location). Lithologic symbols for surface after Weimer and Sonnenberg, 1989 section are shown on Figure 7.

DUDLEY D. RICE

\

\j'

o

o.

o

50

r

1

l

o

FIgurE! 1.

J

kilometers

30 miles

Index map of Denv&!' basin showing present-
(modified Irom Shurr, 1980~ Coritour by numbers and Irom core samples

after Rice, 1984

POG fig. 14

f).'

WYO

KANS

F/100

Gradients

It

Plainview Prospect AREA OF MATURE SOURCE ROCKS (TAINTER,

1984)

, Figure 24. Geothermal gradients in n-cirthern portion of Denver Basin, in FO per 100 ft. C.M.B. is Colorado Mineral Belt, a Precambrian structural trend with a zone of Tertiary intrusions, exposed in the Front Range Uplift. after

Weimer

& Sonnenberg,

1989.

POG fig. 15