U.S Department of the Interior

U.S. Geological Survey

Organic geochemistry of oils from Oil Spring and Florence Oil Field

near Cañon City, Colorado

Paul G. Lillis, Michael P. Dolan, Augusta Warden, and J. David King

U.S. Geological Survey, Denver, CO 80225

Open File Report 98-617

This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial

standards or with the North American stratigraphic code. Any use of trade names is for descriptive

purposes only and does not imply endorsement by the U.S. Government.
1

Abstract

Oil Spring is an oil seep located approximately 6 miles north of Cañon City, Colorado.

The purpose of this study is to determine whether the oil from Oil Spring and the oil from

nearby Florence oil field share a common source. Bulk and molecular geochemical

analyses show that the oil seep is most likely derived from a group of geochemically

similar Cretaceous source rocks including the Carlile Shale, Greenhorn Limestone,

Graneros Shale, and the Mowry Shale. The Florence oil is derived from the Sharon

Springs Member of the Upper Cretaceous Pierre Shale.
2

Introduction

Oil Spring is an oil seep located along Fourmile Creek (formerly called Oil Creek)

approximately 6 miles north of Cañon City, Colorado and the Florence oil field is

approximately 10 miles southeast of Cañon City. Oil Spring and Florence field lie within

the Cañon City-Florence basin which is located just southwest of the Denver basin. The

purpose of this study is to determine whether the oil from Oil Spring and oil from

Florence field share a common source. Most of the oil in the Denver basin is produced

from Lower Cretaceous “D” and “J” sandstone reservoir rocks and is thought to be

derived from a group of geochemically similar Cretaceous source rocks including the

Carlile Shale, Greenhorn Limestone, Graneros Shale, and the Mowry Shale (Clayton and

Swetland, 1980). The oil from Florence field is produced from fractured Upper

Cretaceous Pierre Shale, and is believed to be derived from the Sharon Springs Member

of the Pierre Shale (Swetland and Clayton, 1976; Gautier and others, 1984). The oil from

Oil Spring seep has previously been suggested to be derived from Cretaceous source

rocks (Clayton and others, 1984, personal communication, in Powers and others, 1984).

However, the oil from Oil Spring is seeping from the Jurassic Morrison Formation, which

suggests a Jurassic or older source rock.

Two oil seep samples, one oil-stained sand reported to be derived from the seep, and one

oil sample from Florence field were analyzed for bulk and molecular organic composition

(Table 1). One oil seep sample (97032-001) was reportedly collected in about 1983 and

the other seep sample (97032-002) was collected in 1995. The oil-stained unconsolidated

sand sample (97032-004 or "tourist" sample) was contained in a vial with a label claiming

to be a sample of the first oil discovery in Colorado. We presume that this type of sample

was sold to tourists at local gift shops. The oil samples were collected by Dr. Donald H.

Kupfer, retired geologist from Cañon City, and the oil-stained sand sample was provided

by Dr. Robert J. Weimer, emeritus professor from the Colorado School of Mines. The

Appendix contains a verbatim description of the samples.

Analytical Procedures

Oil samples were transferred from the original plastic containers into metal cans to

preclude organic contamination. Oil gravity was measured directly using hydrometers

calibrated to °API and corrected for temperature. The oil from the oil-stained sand was

extracted by soaking the sand in chloroform for approximately one hour at room

temperature. Most of the chloroform was removed from the extract using a rotary

evaporator with moderate vacuum and a water bath temperature of about 35°C. Oil

concentration in the extract was determined gravimetrically on an aliquot of known

volume. An aliquot of known concentration was placed in a vial and the volume was

reduced by evaporation to about 1 ml under a stream of nitrogen gas at room temperature.

About 2 ml of iso-octane was added to the sample and mixed with a vortex mixer on low

speed. The sample was gently evaporated under a stream of nitrogen gas to about 1 ml.

The iso-octane addition and evaporation step was repeated at least three times until the

chloroform was completely displaced by the iso-octane. As the iso-octane replaced the
3

chloroform, the asphaltene fraction of the oil became insoluble and precipitated out of

solution. Iso-octane was also added to the oil samples to precipitate the asphaltene

fractions. All asphaltene precipitates were then removed by filtration. The maltene

fractions (oil with asphaltenes removed) were separated into saturated hydrocarbon,

aromatic hydrocarbon, and resin fractions by elution chromatography using alumina/silica

columns and elution solvents of increasing polarity.

The C8+ saturated and aromatic hydrocarbon fractions were analyzed with a Hewlett

Packard 6890 gas chromatograph (GC) equipped with a 60m x 0.32mm fused-silica

capillary column (DB-1) and a flame ionization detector. The GC temperature for the

saturated hydrocarbons was programmed from 50°C to 330°C at 4.5°C/minute, and held

at 330°C for 15 minutes. The aromatic hydrocarbons were analyzed under the same

conditions except that the starting temperature was 40°C. Biomarker distributions were

determined by analyzing combined saturated and aromatic hydrocarbon fractions by gas

chromatography-mass spectrometry. A Hewlett Packard 5890 GC with a DB-1701 60 m x

0.32 mm column was directly interfaced to a VG7035 magnetic sector mass spectrometer

operating with a dynamic mass resolution of 3000 (5 percent valley). Multiple ion

detection was accomplished by switching the accelerating voltage at a constant magnetic

field. The selected ions were m/z 191.1800 (terpanes), m/z 217.1956 (steranes), m/z

231.1174 (triaromatic steroids) and m/z 253.1956 (monoaromatic steroids). Peak

identifications were based on elution time and mass spectra (Philp, 1985).

Stable carbon isotope ratios were determined for the C15+ saturated and aromatic

hydrocarbon fractions using a Carlo Erba elemental analyzer (EA) interfaced with a

Micromass Optima continuous-flow isotope ratio mass spectrometer (IRMS). Sample

aliquots were heated to approximately 1800°C in the EA quartz combustion tube filled

with oxygen. The evolved CO2 passed through chromium oxide (to complete oxidation),

copper granules (reducing agent), and anhydrone (to remove water) before being swept

into the IRMS with a helium carrier gas. The results are expressed in the delta (δ)

notation that represents the deviation of the 13C/12C ratio in parts per thousand (per mil, or

‰) relative to the Peedee belemnite (PDB) standard.

Results and Discussion

The bulk geochemical results are listed in Table 2. The 1983 Oil Spring sample has been

moderately altered by evaporation and biodegradation as indicated by the lower gravity

(20°API) and reduced relative concentration of normal alkanes (Figure 1). This is not

surprising given that the oil reportedly sat in an open barrel for more than ten years

(Appendix). The Oil Spring sample that was collected in 1995, and the Florence oil

sample are relatively unaltered except for minor evaporation of the light normal alkanes

between C8 and C15 (Figure 1). The API gravity of the Florence oil sample (30°) is

similar to that reported for the field (32°) by Powers and others (1984). The extracted

Tourist sample has experienced severe evaporation as indicated by the missing
4

hydrocarbons below C13 and has experienced minor biodegradation as indicated by the

lower concentration of normal alkanes and the large baseline hump also known as the

unresolved complex mixture (Figure 1).

 The relative degree of alteration of the seep samples is also indicated by the relative

concentrations of the column chromatography fractions listed in Table 2. For example,

the most degraded sample, Tourist, has the highest concentration of asphaltenes and the

lowest concentration of saturated hydrocarbons. Conversely, the 1995 seep sample has

the lowest concentration of asphaltenes and the highest concentration of saturated

hydrocarbons.

The pristane/phytane ratios of the 1983 and 1995 samples are nearly identical (2.18 and

2.15) even though the former sample has experienced some minor biodegradation. The

Tourist sample has a lower pristane/phytane ratio (1.42) that probably resulted from

increased evaporative loss of the lighter isoprenoid (pristane). The seep oil values are

similar to those of oils from the Lower Cretaceous “D” and “J” sandstone reservoirs in

the Denver Basin. Clayton (personal communication, 1998) reports pristane/phytane

values ranging from 1.86 to 2.14 and averaging 1.95 for 16 oil samples. The Florence oil

has a slightly lower pristane/phytane ratio (1.65) and is similar to a Florence oil (1.6)

reported by Gautier and others (1984).

The δ

13C saturated and aromatic hydrocarbon data of the oil seep exhibit some scatter due

to alteration effects of the 1983 and Tourist samples (Table 2). We consider the 1995 seep

sample to be the least altered and, therefore, the δ

13C data to be the best values to use for

correlation purposes. The 1983 seep sample has a slightly heavy δ

13C saturated

hydrocarbon value and a significantly light δ

13C aromatic hydrocarbon value when

compared with the other two seep samples. The heavy saturated hydrocarbon isotope ratio

may be due to biodegradation of the n-alkanes but the light aromatic hydrocarbon isotope

ratio cannot be explained. The Tourist δ

13C values are slightly heavier than the 1995 seep

sample, probably due to greater biodegradation of the Tourist sample. The Florence oil

has the lightest δ

13C values for both saturated and aromatic hydrocarbons, and is similar

in isotopic composition to another Florence oil (δ

13C sats = -28.58, δ13C arom = -27.47)

reported by Gautier and others (1984). The 0.6 per mil difference between the Florence

oil and the oil seep is not large but is distinct enough to discount analytical error. The

difference may be due to a slightly different source composition, slight difference in

maturity, or minor alteration. Clayton and Swetland (1980) report that the δ

13C saturate

values of the oils from the Lower Cretaceous "D" and "J" sands of the Denver Basin

range from -28.0 to -29.0 per mil. Based on these data the oil seep (-28.05 per mil) and

the Florence oil sample (-28.65 per mil) correlate with the Lower Cretaceous oils.

The aromatic hydrocarbon fractions of the oil seep samples appear to be relatively

unaltered in the 1983 and 1995 samples and significantly evaporated in the Tourist

sample as indicated by the gas chromatography data (Figure 2). The aromatic

hydrocarbon composition of the Florence oil appears to be quite different with small
5

concentrations of naphthalenes and high concentrations of unknown compounds eluting

after 50 minutes.

Biomarker compounds are relatively resistant to biodegradation and evaporation and,

consequently, are useful for correlation. The biomarker mass chromatograms are shown

on Figures 3 through Figure 6 with compound identifications in Table 3 and selected

biomarker ratios in Table 4. The tricyclic and pentacyclic terpane (m/z 191), sterane (m/z

217), monoaromatic sterane (m/z 253), and the triaromatic sterane (m/z 231) composition

of the three oil seep samples are virtually identical (Table 4). This correlation indicates

that all of the bulk geochemical differences between the seep samples discussed above are

caused by biodegradation, evaporation, or other alteration effects.

Although the biomarker compositions of the Florence and seep oils are similar,

differences are observed upon closer inspection. The Florence oil contains two extra

compounds in the m/z 191 chromatogram (Figure 3); an unidentified terpane (peak a) and

oleanane (peak o). Oleanane is derived from angiosperms which first became prominent

in the Late Cretaceous (Ekweozor and Udo, 1988). The Florence oil also contains

relatively higher concentrations of C25 tricyclic terpane (peak 3), C24 tetracyclic terpane

(peak 5), and norhopane (peak 8) when compared to the seep oil (Table 4). The sterane

mass chromatogram (Figure 4) of the Florence oil displays a relatively higher

concentration of C28 steranes and a lower concentration of C29 steranes when compared to

the oil seep (Table 4). These data suggest that the Florence oil was derived from a source

rock with relatively higher concentration of marine organic matter and a lower

concentration of terrestrial organic matter than the source rock of the seep oil (Huang and

Meinschein,1979; Moldowan and others, 1985). The seep oil has a relatively higher

diasterane concentration (C27 R dia/C27 R cholestane) which may be caused by either

slightly higher thermal maturity (Seifert and Moldowan, 1978) or a more clay-rich source

rock (Sieskind and others, 1979). The higher C28 steranes in the Florence oil is also

reflected in the triaromatic steranes (Figure 5) with a higher C27 (one carbon is lost during

aromatization). However, the monoaromatic sterane distribution (Figure 6) of the two oils

are quite similar. The low molecular weight triaromatic steranes (C20, C21) exhibit higher

concentration in the oil seep, suggesting higher levels of thermal maturity (Table 4).

Interestingly, there is an apparent contradiction as to the relative thermal maturity of the

two oils (Table 4). Several geochemical parameters suggest that the seep oil (1995) is

more mature than the Florence oil including pristane/n-C17, Ts/Tm, C29 Ts/norhopane,

diasterane/sterane, C23 tricyclic/hopane and C20+C21 tri/triaromatic sterane ratios.

Conversely, some parameters suggest that the Florence oil has about the same thermal

maturity including the 20S/S+R ααα C29 sterane, ββ/ββ+αα C29 sterane, and

triaromatic/triaromatic+ monoaromatic sterane ratios.

Published biomarker data on oils in Colorado is very limited. The m/z 191 and 217 mass

chromatograms of the "J" sandstone oil from Lindon Field (Clayton, 1989) are very

similar to those of the seep oil. The m/z 217 mass chromatogram of the Florence oil is

very similar to that of a Florence oil reported by Gautier and others (1984).
6

Conclusions

1. The two oil seep samples and the oil-stained sand sample (Tourist) constitute one oil

family probably derived as reported from the Oil Spring near Cañon City, Colorado.

Differences in composition can be explained as variations in biodegradation and/or

evaporation of the parent oil after reaching the surface.

2. The oil seep composition is similar to that of the Florence oil and to other Cretaceous

oils in Denver Basin, Colorado. However, minor but distinct compositional differences

indicate that the seep oil is not derived from the same organic facies as the Florence oil.

Swetland and Clayton (1976) also found that the Florence oil does not correlate with the

Lower Cretaceous oils based on C4 to C7 hydrocarbon composition.

3. The oil seep is most likely derived from Lower Cretaceous source rocks as indicated by

the similar δ

13C hydrocarbon and pristane/phytane values as the Lower Cretaceous oils in

the Denver Basin, the similarity in biomarker composition with the Lower Cretaceous "J"

sandstone oil from Lindon Field, and the absence of oleanane. It is less likely, but

possible that the oil seep may be derived from the Sharon Springs Member of the Pierre

Shale that has a relatively higher content of terrestrial organic matter; Gautier and others

(1984) found that Sharon Springs has higher terrestrial organic matter in the northerncentral Denver Basin (Boulder and Fort Collins, Colorado).

4. The Florence oil sample from this study correlates with another Florence oil reported

by Gautier and others (1984) and with their extracts of the Sharon Springs Member of the

Pierre Shale. Furthermore, the Florence oil sample in the present study contains oleanane

which is consistent with an Upper Cretaceous (or younger) source rock.
7

References

Clayton, J.L., 1989, Geochemical evidence for Paleozoic oils in Lower Cretaceous O

sandstone, Northern Denver Basin: American Association of Petroleum

Geologists Bulletin, v.73, p.977-988.

Clayton, J.L. and Swetland, P.J., 1980, Petroleum generation and migration in Denver

Basin: American Association of Petroleum Geologists Bulletin, v.64, p.1613-

1633.

Ekweozor, C.M. and Udo, O.T., 1988, The oleananes: origin, maturation and

limits of occurrence in southern Nigeria sedimentary basins: Organic

Geochemistry, v. 13, p. 131-140.

Gautier, D.L., Clayton, J.L., Leventhal, J.S. and Reddin, N.J., 1984, Origin and sourcerock potential of the Sharon Springs Member of the Pierre Shale, Colorado and

Kansas, in Woodward, J., Meissner, F.F., and Clayton, J.L., eds., Hydrocarbon

source rocks of the Greater Rocky Mountain Region: Rocky Mountain

Association of Geologists, Denver, Colorado, p.369-385.

Huang, W. Y., and Meinschein, W. G., 1979, Sterols as ecological indicators:

Geochimica et Cosmochimica Acta, v. 43, p. 739-745.

Hunt, J.M., 1979, Petroleum geology and geochemistry: San Francisco, Freeman

and Company, 617 p.

Moldowan, J. M., Seifert, W.K., and Gallegos, E.J., 1985, Relationship between

petroleum composition and depositional environment of petroleum source

rocks: American Association of Petroleum Geologists Bulletin, v. 69,

p.1255-1268.

Philp, R.P., 1985, Fossil Fuel Biomarkers - Applications and Spectra: Elsevier,

Amsterdam, 294p.

Powers, R.B., Molenaar, C.M., Jacob, A.F. and Heinrich, P.V., 1984, Road log first day

(total miles 180.2) Lakewood to Pueblo, in Woodward, J., Meissner, F.F., and

Clayton, J.L., eds., Hydrocarbon source rocks of the Greater Rocky Mountain

Region: Rocky Mountain Association of Geologists, Denver, Colorado, p.535-

547.

Scalan, R S., and Smith, J. E., 1970, An improved measure of the odd- even

predominance in the normal alkanes of sediment extracts and petroleum:

Geochimica et Cosmochimica Acta, v. 34, p. 611-610.
8

Seifert, W.K. and Moldowan, J.M., 1978, Applications of steranes, terpanes, and

monoaromatics to the maturation, migration, and source of crude oils: Geochimica

et Cosmochimca Acta, v. 42, p.77-95.

Sieskind, O., Joly, G., and Albrecht, P., 1979, Simulation of the geochemical

transformations of sterols: superacid effect of clay minerals: Geochimica

et Cosmochimica Acta, v.43, p. 1675-1679.

Swetland, P.J. and Clayton, J.L., 1976, Source beds of petroleum in the Denver Basin:

U.S. Geological Survey Open File Report 76-572, 22p.

Washburne, C.W., 1909, The Florence oil field, Colorado: U.S. Geological Survey

Bulletin, B0381-D, p. 517-544.

Acknowledgments

We would like to thank Jerry L. Clayton and Debra Higley of the U.S. Geological Survey

for their critical review of the manuscript. The oil samples were provided by Dr. Donald

H. Kupfer, retired geologist from Cañon City, and Dr. Robert J. Weimer, emeritus

professor from the Colorado School of Mines.
9

Table 1. Sample Information

Sample Identification Job Number Location Latitude Longitude Elevation

 (ft)

Oil Spring 1983, K/O-1 97032-001 Sec3-T18S-R70W N38.51340 W105.21127 5620

Oil Spring 1995, K/O-2 97032-002 Sec3-T18S-R70W N38.51340 W105.21127 5620

Oil Spring, Tourist vial 97032-004 Sec3-T18S-R70W N38.51340 W105.21127 5620

Fee 6, Well #370, K/O-3 97032-003 Sec21-T19S-R69W N38.38317 W105.12302 5206
10

Table 2. Bulk Oil Geochemistry

Sample Identification Grav Sats Arom NSO Asph Rec Vol S/A Pr/Ph CPI OEP δ

13C δ13C

°API wt% wt% wt% wt% wt% wt% Sats Arom

Oil Spring 1983, K/O-1 20.3 55.9 22.8 11.3 10.0 85.0 8.8 2.5 2.18 nd nd -27.36 -27.34

Oil Spring 1995, K/O-2 25.9 65.2 21.1 9.4 4.2 80.8 5.3 3.1 2.15 1.00 0.99 -28.05 -26.94

Oil Spring, Tourist vial nd 35.8 13.7 15.5 34.9 93.4 0.0 2.6 1.42* 1.05 1.02 -27.69 -26.88

Fee 6, Well #370, K/O-3 30.0 74.0 20.1 5.6 0.3 93.1 10.6 3.7 1.65 1.05 1.01 -28.65 -27.59

Definitions and Comments

Grav = oil gravity in °API

Sats = normalized weight percent C15+ saturated hydrocarbons

Arom= normalized weight percent C15+ aromatic hydrocarbons

NSO = normalized weight percent C15+ N, S, O - containing hydrocarbons

Asph = normalized weight percent C15+ asphaltenes (insoluble in iso-octane)

Rec = weight percent recovered from column (non recovered fractions include lost volatiles less than C15 , highly polar and high

molecular weight compounds held up in the column)

Vol= weight percent volatile less than C15

S/A= saturated hydrocarbons/aromatic hydrocarbons, w/w

Pr/Ph = pristane/phytane, peak height

CPI = carbon preferential index from n-C25 to n-C35, peak height (Hunt, 1979)

OEP= odd/even predominance centered at n-C29, peak height (Scalan and Smith, 1970)

nd = no data

* = not reliable due to evaporation
11

Table 3. Tentative Biomarker Compound Peak Identifications

1 C23 Tricyclic terpane

2 C24 Tricyclic terpane

a unidentified terpane

3 C25 Tricyclic terpane

4 C26 [22S] Tricyclic terpane + C26 [22R] Tricyclic terpane

5 C24 Tetracyclic terpane

6 18α Trisnorneohopane [C27 Ts]

7 17α Trisnorhopane [C27 Tm]

8 Norhopane [C29]

9 18α Neonorhopane [C29]

o Oleanane [C30]

10 Hopane [C30]

11 22S Homohopane [C31]

12 22R Homohopane [C31]

13 22S Bishomohopane [C32]

14 22R Bishomohopane [C32]

15 5α14α17α 20R cholestane [C27]

16 5α14α17α 20R Methylcholestane [C28]

17 5α14α17α 20S 24-Ethylcholestane [C29]

18 5α14β17β 20R 24-Ethylcholestane [C29]

19 5α14β17β 20S 24-Ethylcholestane [C29]

20 5α14α17α 20R 24-Ethylcholestane [C29] + 5α14α17α 20S 24-n-propylcholestane [C30]

21 5α14α17α 20R 24-n-propylcholestane [C30]
12

Table 4. Comparison of seep and Florence oils using biomarker data.

Biomarker Ratio Tourist 1983 seep 1995 seep Florence Comparison

97032-

004

97032-

001

97032-

002

97032-

003

C24 tricyclic/C23 tricyclic 0.78 0.71 0.68 0.67

C25 tricyclic/C23 tricyclic 0.68 0.59 0.57 0.77 negative correlation

C24 tetracyclic/C26 tricyclic 0.47 0.42 0.45 0.62 negative correlation

C23 tricyclic/hopane 0.09 0.10 0.10 0.07 maturity difference

Ts/Tm (peak 6 / peak 7) 2.88 3.14 2.85 1.46 maturity difference

Norhopane/hopane 0.34 0.35 0.34 0.46 negative correlation

Neonorhopane/norhopane+neo. 0.44 0.46 0.44 0.32 maturity difference

Oleanane/hopane 0.03 0.04 0.04 0.11 negative correlation

C31 S/S+R homohopane 0.60 0.59 0.58 0.62 same maturity

C32 S/S+R homohopane 0.57 0.56 0.56 0.58 same maturity

C27 R dia/C27 R cholestane 0.81 0.77 0.86 0.41 negative correlation

C27/C27-C29 steranes 0.44 0.46 0.45 0.44

C28/C27-C29 steranes 0.25 0.25 0.25 0.31 negative correlation

C29/C27-C29 steranes 0.31 0.28 0.29 0.24 negative correlation

C30/C27-C30 steranes 0.07 0.06 0.08 0.08

S/S+R C29 ethyl cholestane 0.47 0.49 0.46 0.48 same maturity

ββ/αα C29 ethyl cholestane 0.58 0.60 0.59 0.59 same maturity

C20+C21 tri/triaromatics 0.24 0.26 0.26 0.04 maturity difference

Tri/triaromatics + monoaromatics 0.78 0.74 0.73 0.69 same maturity

C28 tri/C28 tri +C29

monoaromatics

0.79 0.74 0.76 0.76 same maturity
13

Appendix. Sample descriptions that came with the samples.

Below is a verbatim description of the three “K/O” samples:

Oil Samples from Florence Basin

D.H. Kupfer, Sept. 1995.

Sample #1: K/O-1 Oil Spring, 1983?

After Beale (sp?) (of Woodland Park), leasee, died about 1983, owner, Frank Dilley, cleaned

up what he found left around the Oil Spring (equipment, etc). Then, or probably somewhat

later, he removed some drums of oil and plastic gallon jugs of oil to Dilley’s barn (2 miles

north of the Oil Spring).

 This sample is from one of the gallon jugs, and probably represent Oil Spring oil of circa

1982 +/- 2 years. The jug was 4/5 full and had a small hole above the oil line. Presumably,

it has been stored in the plastic milk-type jug for over ten years and possibly was open to

minor air circulation for part of that time.

Sample #2: K/O-2 Oil Spring, 1995, (27Aug)

In 1993, the shaft at the Oil Spring was filled with sand/mud with a back-hoe, and the general

drainage disrupted. During the summer of 1994, no seepage was observed. In April, 1995,

some new oil seemed to have seeped out around the drill-hole pipe, a few feet south of the

filled shaft. On July 21, 1995, more apparent seepage was observed, and a small pit (1x1x1

feet) was dug and covered with a bucket. On August 27, the pit was 3⁄4 full, but mainly with

water (brine?). A 2-quart sample was taken and the water decanted, to the present sample (5

ounces).

Sample #3: K/O-3 Florence Oil Field, September 2, 1995

Oil from Fee 6, Well #370, SW, NW, Section 21, T19/R69.

Taken 2Sp95 from the feedpipe leading to tank (well was not being pumped at this time).

Well produces 3⁄4 to 1 bbl/dy, but having problems at the moment, so not being pumped until

fixed. Kelly Black, the pumper, said that this well had not produced for about 20 years (see

Washburne, below). It was recompleted and the second production started last August

(1994) and it has been flowing OK since (K. Black).

 It is a very rich golden brown (Black called it "green"), light, thin oil. Black says a lot

of gasoline-content is typical of the field; not much variation in the oil of the field from well

to well, or from north to south end (this well is north).

Washburne (USGS, 1909, page 540), lists this as a United Oil Company well; his map shows

it was active in 1909, a well with gas, and an oil production over 1 million gallons (from

legend).

------------------------------------------------------------------------------------------------------

Below is the label text of the “Tourist” vial of Oil Spring:
14

First Oil Discovery in Colorado

The oil in this bottle is from the seep on Oil Creek, 6 miles north of Canon City. Here in

1863 A. M. Cassedy brought in the first oil well in Colorado, only about three years after the

first discovery of oil in the United States, at Titusville, Pennsylvania.
Oil Seep (1983) 97032-001

0

200

400

600

800

10 15 20 25 30 35 40 45 50 55 60 65 70

Oil Seep (1995) 97032-002

0

200

400

600

10 15 20 25 30 35 40 45 50 55 60 65 70

Oil Seep (Tourist Vial) 97032-004

0

100

200

300

400

10 15 20 25 30 35 40 45 50 55 60 65 70

Florence oil Field 97032-003

0

200

400

600

10 15 20 25 30 35 40 45 50 55 60 65 70

Figure 1. Gas chromatograms of saturated hydrocarbons. Numbered peaks are n-alkane carbon numbers. pristane pristane pristane pristane phytane phytane phytane phytane

15

20

15

20

25

30

15

20

25

30

15

10

8

20

25

30

15

Peak Intensity (millivolts)

Retention time (minutes)
Oil Seep (1983) 97032-001

40

60

80

10 15 20 25 30 35 40 45 50 55 60 65 70

Oil Seep (1995) 97032-002

50

100

150

10 15 20 25 30 35 40 45 50 55 60 65 70

Oil Seep (Tourist Vial) 97032-004

50

100

150

10 15 20 25 30 35 40 45 50 55 60 65 70

Florence oil field 97032-003

50

100

150

200

10 15 20 25 30 35 40 45 50 55 60 65 70

Figure 2. Gas chromatograms of aromatic hydrocarbons.

naphthalenes

16

Retention time (minutes)

Peak Intensity (millivolts)
Oil Seep (1983) 97032-001

0

50

100

150

200

25 30 35 40 45 50 55 60 65 70

Oil Seep (1995) 97032-002

0

50

100

25 30 35 40 45 50 55 60 65 70

Oil Seep (Tourist Vial) 97032-004

0

20

40

60

80

100

25 30 35 40 45 50 55 60 65 70

Florence oil field 97032-003

0

100

200

300

25 30 35 40 45 50 55 60 65 70

Figure 3. Mass chromatograms (m/z 191.1800) of terpanes. Peak numbers refer to Table 3.

1

2 3 4 5

6

7

8

9

10

11

12 13

14

o

a

1

2 3

4

5

6

7

8

9

10

11

12

13

14

Retention time (minutes)

Peak Intensity (millivolts)

17
Oil Seep (1983) 97032-001

0

20

40

60

26 28 30 32 34 36 38 40 42 44 46 48 50 52 54

Oil Seep (1995) 97032-002

0

10

20

30

40

26 28 30 32 34 36 38 40 42 44 46 48 50 52 54

Oil Seep (Tourist Vial) 97032-004

10

20

30

26 28 30 32 34 36 38 40 42 44 46 48 50 52 54

Florence oil field 97032-003

0

20

40

60

80

100

26 28 30 32 34 36 38 40 42 44 46 48 50 52 54

15

20

21

16

|--Diasteranes---|

|--Diasteranes--|

Figure 4. Mass chromatograms (m/z 217.1956) of steranes. Peak numbers refer to Table 3.

17

18

19

15

16

16

17

17

18

19

19

20

20

21

21

18

18

Retention time (minutes)

Peak Intensity (millivolts)
Oil Seep (1983) 97032-001

0

20

40

60

30 35 40 45 50 55 60

Oil Seep (1995) 97032-002

0

10

20

30

40

30 35 40 45 50 55 60

Oil Seep (Tourist Vial) 97032-004

0

10

20

30

30 35 40 45 50 55 60

Florence oil field 97032-003

0

50

100

150

200

250

30 35 40 45 50 55 60

Figure 5. Mass chromatograms (m/z 231.1174) of triaromatic steranes. Peak numbers are carbon numbers.

20

21

26S

28S

27R 28R

26R+27S

28R 28S

27R

28R

28S

27R

20 21

Peak Intensity (millivolts)

Retention time (minutes)

19
Oil Seep (1983) 97032-001

10

20

30

26 28 30 32 34 36 38 40 42 44 46 48

Oil Seep (1995) 97032-002

5

10

15

20

26 28 30 32 34 36 38 40 42 44 46 48

Oil Seep (Tourist Vial) 97032-004

2

4

6

8

10

12

26 28 30 32 34 36 38 40 42 44 46 48

Florence oil field 97032-003

0

50

100

26 28 30 32 34 36 38 40 42 44 46 48

Figure 6. Mass chromatograms (m/z 253.1956) of monoaromatic steranes.

Retention time (minutes)

Peak Intensity (millivolts)

20