Finding Oil and Gas from Space

Landsat and other remote sensor systems (SPOT; JERS; radar, etc.) have been heavily used in
searching for surface indicators of "leaking" subsurface oil and gas. The general approach to
petroleum exploration is described. One line of investigation looks at structural analysis of space
imagery in search of subsurface traps. Another, of infrequent success, seeks alteration at the
surface caused by chemical changes related to surface-reaching oil or gas. In the early days of
Landsat-1, a study in the Anadarko Basin of Oklahoma sought to demonstrate how alteration
anomalies and lineaments analysis can aid in finding new petroleum by showing a relationship to
already known fields. This pioneering program led to ambiguous but interesting results. Other
examples are also considered on this page. The importance of Canadian oil sands as a major
source of petroleum (oil) in the future receives special attention.
Finding Oil and Gas from Space
If precious metals are not your forte, then try the petroleum industry. Exploration for oil
and gas has always depended on surface maps of rock types and structures that point
directly to, or at least hint at, subsurface conditions favorable to accumulating oil and
gas. Thus, looking at surfaces from satellites is a practical, cost-effective way to produce
appropriate maps. But verifying the presence of hydrocarbons below surface requires
two essential steps: 1) doing geophysical surveys; and 2) drilling into the subsurface to
actually detect and extract oil or gas or both. This Tutorial website sponsored by the
Society of Exploration Geophysicists is a simplified summary of the basics of
hydrocarbon exploration.
Oil and gas result from the decay of organisms - mostly marine plants (especially
microscopic algae and similar free-floating vegetation) and small animals such as fish that are buried in muds that convert to shale. Heating through burial and pressure from
the overlying later sediments help in the process. (Coal forms from decay of buried
plants that occur mainly in swamps and lagoons which are eventually buried by younger
sediments.). The decaying liquids and gases from petroleum source beds, dominantly
shales after muds convert to hard rock, migrate from their sources to become trapped in
a variety of structural or stratigraphic conditions shown in this illustration:
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From Physical Geology: Earth Revealed by McGeary and Plummer, First Ed., W.C.
Brown Publ.
The anticlinal trap, among the most common, is nicely revealed in a real world setting in
this old photograph:
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The oil and gas must migrate from deeper source beds into suitable reservoir rocks.
These are usually porous sandstones, but limestones with solution cavities and even
fractured igneous or metamorphic rocks can contain openings into which the petroleum
products accumulate. An essential condition: the reservoir rocks must be surrounded (at
least above) by impermeable (refers to minimal ability to allow flow through any openings
- pores or fractures) rock, most commonly shales. The oil and gas, generally confined
under some pressure, will escape to the surface - either naturally when the trap is
intersected by downward moving erosional surfaces or by being penetrated by a drill. If
pressure is high the oil and/or gas moves of its own accord to the surface but if pressure
is initially low or drops over time, pumping is required.
Exploration for new petroleum sources begins with a search for surface manifestations of
suitable traps (but many times these are hidden by burial and other factors govern the
decision to explore). Mapping of surface conditions begins with reconnaissance, and if
that indicates the presence of hydrocarbons, then detailed mapping begins. Originally,
both of these maps required field work. Often, the mapping job became easier by using
aerial photos.
After the mapping, much of the more intensive exploration depends on geophysical
methods (principally, seismic) that can give 3-D constructions of subsurface structural
and stratigraphic traps for the hydrocarbons. Then, the potential traps are sampled by
exploratory drilling and their properties measured.
Remote sensing from satellites or aircraft strives to find one or more indicators of surface
anomalies. This diagram sets the framework for the approach used; this is the so-called
microseepage model, which leads to specific geochemical anomalies:
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The surface geochemical expression of petroleum seepage can take many forms: (1)
anomalous hydrocarbon concentrations in sediment, soil, water, and even atmosphere
(2) microbiological anomalies and the formation of "paraffin dirt" (3) anomalous nonhydrocarbon gases such as helium and radon (4) mineralogical changes such as the
formation of calcite, pyrite, uranium, elemental sulfur, and certain magnetic iron oxides
and sulfides (5) clay mineral alterations (6) radiation anomalies (7) geothermal and
hydrologic anomalies (8) bleaching of redbeds (9) geobotanical anomalies (10) altered
acoustical, electrical, and magnetic properties of soils and sediments.
Landsat, and other space imaging systems, serve as mega-photos that depict large
areas, within which clues to subsurface conditions may be evident. In general, most of
the obvious structures that have surface expression had been discovered and mapped
(to varying extents) over much of the world. Some regions, however, were not
adequately mapped even in the 1970s, so that the advent of higher-resolution space
imagery proved a boon to energy companies seeking new sources of fossil fuels.
Sometimes the imagery proved especially sensitive to subtle indications of interior
structures. For instance, fractures around structures in known oil/gas fields may extend
further, as seen in the coherent space images, than suspected from ground work. Also,
drainage patterns at broader scales may reflect control by underlying rocks involved in
suitable traps. And even vegetation distribution may disclose signs of structure. These
and other indicators discernible in space imagery appealed to exploration geologists as
another means to survey large areas.
The two most useful indicators discernible in airborne or spacecraft remote sensors data
are fracture systems (mainly lineaments) which can control or affect the migration of gas
and oil to the surface and geochemical alterations of surficial rocks by hydrocarbons
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which lead to compositional and color changes. This second effect is reviewed on a
website that deals with hydrocarbon detection.
We will now illustrate these ideas by examining and evaluating one of the first case
studies using Landsat-1 to demonstrate the feasibility of direct exploration from space.
This pilot study, conducted jointly by the Eason Oil Corp. and the Earth Satellite Corp. of
Rockville, MD, sheds considerable light on effective criteria for recognizing conditions
that might relate to buried hydrocarbons. In addition, some of the pitfalls associated with
the space approach were also discovered by carefully assessing the results reported by
these investigators.
The strategy behind the study was to look at Landsat imagery of a region already
established as a petroleum province, giving special attention to telltale surface
indications of the presence of known underlying fields. The investigators used standardprocessed and computer-enhanced versions. Rather than test capabilities in a region
where there is obvious structural control and other clear-cut evidence, they selected
producing areas where the surface does not give clear indication of subsurface
conditions. If they could succeed in detecting hydrocarbons under such difficult
circumstances, then Landsat would increase in stature as an oil/gas discriminator .
The Anadarko Basin of south-central Oklahoma fits this requirement well. Located in the
eastern Great Plains, with most of the land used for farming and ranching, the Basin is
one of the great producers of the mid-continent petroleum province, which also includes
much of Texas, as well.
The Basin is a down-sag in the crust that has allowed up to 15,200 m (50,000 ft) of
Paleozoic sedimentary rock to accumulate. Structurally, the Basin is an asymmetrical
geosyncline (a regional-scale downfold), with the deepest part near the south edge. Oil
and gas are present in porous rocks associated with structural (anticlines; fault blocks)
and stratigraphic traps. Large gas fields occur mainly along the Basin's western half,
whereas oil is more common in the eastern half. Wells as deep as 7,600 m (25,000 ft)
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have recovered both hydrocarbons, although most pay zones are between 2,750-5,250
m (9,000-15,000 ft).
Generally, surface expression of underlying oil or gas traps in the Basin is meager,
because first, there are few structural indicators in the flat-lying sediments atop older
folded units and second,there is overprinting of geologic features by vegetation and land
use (grasslands; hilly sage-covered terrain; and wheat farmlands). The Eason
Oil/Earthsat investigators decided to focus on two search elements: previously
undiscovered fractures and subtle chemical alterations of surface rocks by escaping
hydrocarbons.
Lineaments analysis was conducted by Eason Oil using Landsat image transparencies
backlighted on a light table. The linear features they picked are shown by lightweight
black lines on the map below. Superposed as brown and green-black heavier lines are
faults that had previously been discovered and mapped. As a geographic reference, note
the meander bends (curved segments) of the Canadian River, traced in blue. The
majority of the Landsat-mapped linear features are inconspicuous in the imagery. Many
of them are suspect, i.e., they could be non-geological or some type of lighting artifacts.
As first mentioned in Section 2, a group of four geologists, including this writer (NMS), at
Goddard Space Flight Center, decided to check on the reproducibility of these map
results, using the same April, 1973 Landsat MSS full scene (see below). Each person
used the same transparencies (mostly winter images) as Eason Oil and worked
independently of one another to minimize bias. When done, we registered the tracings to
a base map, on which the Eason Oil lineaments were also plotted, as seen below. The
comparison disclosed rather startling discrepancies in terms of variance between the two
groups. We found only about 20% of the total linear features in common. Eason Oil
chose approximately 35% of the questionable features, exclusively, while Goddard
geologists chose the remaining 45%, which represented those "missed" by Eason Oil.
We immediately suspected that this kind of result is partially due to considerable
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subjectivity in deciding whether a given linear feature a) really exists, b) is geological in
nature, and c) means anything.
This suspicion was reinforced by comparing the linear features selected by the four
Goddard geologists. Here are the results - a mishmash that requires the following
interpretation:
Of the 785 linear features identified by all four combined, only 4 (0.5%) were noted by
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every operator. From the remainder, 3 operators mutually selected 37 (4.7%), two
operators agreed on 140 (17.8%), and the rest, 604 (77%), each operator found
exclusively. This type of result has been reported in similar studies, although the above
scores were particularly discouraging. Each geologist had ample experience in
photointerpretation and special skills in analyzing Landsat imagery. Their choices were
justifiable but overall, our results were questionable.
5-10: In this experiment, and in the technique of picking linear features in space
imagery, what do you think was really going on behind the end result of some
many linears being found but not consistently by multiple interpreters? ANSWER
The bottom line here is that there often is a strong tendency towards overkill in choosing
features that appear to be meaningful lineaments. So many are drawn that it would take
a monumental field effort to check them out. If plotted as rose diagrams (see page 2-9),
they may reveal valid trends for the orientations of regional fractures, because
statistically lineaments of non-geological nature should be in the minority. (A study of
obvious lineaments in the Adirondacks confirmed this result.) Of the 200+ prominent
ones in the Anadarko Basin that were field-checked, geological fractures directly or
indirectly controlled most of them, but about 20% related to human factors, such as
fence lines, roads, etc. Thus, we conclude that we should combine lineaments analysis
with other indicators of mineralization or hydrocarbons. This combining would encourage
geologists to field-check particular sites to verify the lineament presence and nature and
their possible correlation with these indicators.
The Eason Oil study sought to recognize such indicators. Their interpreters delineated
certain geomorphic anomalies, such as circular patterns and unusual drainage. In the
course of their image appraisals, they noticed unexpected tonal patterns that looked a bit
like light-colored smudges on the images, such as evident in the April, 1973 full Landsat
MSS scene that became the reference base for the study. These they called "hazy"
features, as seen here:
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We labeled three typical hazy patterns A, B, and C. The one at A, at a bend in the
Canadian River, is especially prominent, and occurs over a known oil field.
A standard false color subscene (computer-enhanced) around A shows the hazy to have
a bluish-white color similar to soils in barren fields. Note the road pattern and white
blotches which are accesses to producing wellheads. The yellowish areas coincide with
unaltered Permian (late Paleozoic) red beds.
When we process this April Multispectral Scanner image into three ratio bands that we
then combine into a color image (4/5 = Blue; 5/6 = Green; 7/5 = Red), the hazy feature at
A takes on a unique yellow-green, and the red beds become orangish.
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The signature for the hazy area, seen in darker orange-brown, is conspicuously different
from its surroundings. It is associated with a small oil field that was developed after the
Oil and Gas Map of the U.S. was published (see below). An aerial photo shows the
roads that cross the hazy patch (inside the large meander loop of the Canadian River):
One might argue that the activities from the drilling had somehow lightened the whole
immediate area, accounting for the "hazy". But, this is unlikely, especially since other
hazies usually do not have active oil fields associated with them. The lighter tone is more
likely to be a condition within the soil.
From the multiseasonal data sets, only those scenes imaged in late winter to early spring
show hazies. At other times of the year, vegetation masks the phenomenon. To
understand their explanation of the features, we look now at this photograph of two rock
types:
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The rock on the far left is a sample from the red beds (sandstones) of Permian age. Next
to it is the same material that has been color bleached to yellow-brown by converting iron
oxide cement into hydrated iron oxides (analogous to rust). The gray rock on the far right
is a limestone (calcium carbonate). To its left is a gypsum rock (hydrated calcium
sulphate). Both interior rocks appear to be altered equivalents of the primary exterior
rocks. In the field, comparable altered rocks can occupy many square miles.
To account for these hazy features, the Eason Oil people postulated that chemical
reactions affected the iron cement, bleaching it out, and/or transformed the carbonates
into sulphates. This, they surmise, happens when sulphur-laden gases or fluids leaked
out of petroleum traps and rose towards the surface, interacted with susceptible rocks,
and brought about compositional changes. Microseeps along lineament would be
particularly effective.
About the time of their conclusion, evidence for such changes was reported as the
Doctoral thesis of Terrence Donovan (later of the U.S.G.S.), in which escaping
hydrocarbons drastically altered rocks above the Cement Field, at the southeast edge of
the Anadarko Basin. Dr. Donovan found a pronounced set of anomalous values of the
ratio of C13 to C12 in samples collected over both producing zones in the field, shown as
contoured areas below:
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These values represent some of the highest departures from normal ratios known
anywhere in the world. He attributed them to the effects of chemical action by carbon-rich
fluids on the rocks which, as a consequence, appear bleached. The Cement Field does
not show any evident hazy-type anomaly in the imagery Eason Oil used. But an image
processed by EarthSat did show a whitening about where the Cement Field is located,
seen as a lighter tone near the center of the image (this is a winter scene, and a trace of
snow is found around a reservoir to the northwest, but appears absent in the vicinity of
the Cement Field).
Accepting this alteration hypothesis, the Eason Oil group looked for at least partial
coincidence between these hazies and the surface projections of subsurface oil or gas
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fields. Of the 57 anomalies they mapped in a control segment of the imagery, they
claimed an association with 42 producing fields. Another six occurred above or near nonproducing structures, and only 9 showed no coincidence. If this observation remained
true, then detecting hazies, sometimes correlative with lineament concentrations, could
promise a powerful new way to hunt for oil and gas using space imagery.
The present writer (NMS), being skeptical in habit, decided to challenge these findings.
The begging question: To what extent do the hazy anomalies correspond to known oil
and gas field distributions. Here is a part of the Oil and Gas Map of the U.S. published by
the American Association of Petroleum Geologists (AAPG):
On this map, the Cement Field is shown in a unique color - a purplish-brown. Next, here
is the Eason Oil Map of the hazies shown in purple-blue:
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It's hard to check the degree of correspondence by shifting between the two maps. So, I
traced the outlines of the Eason Oil hazy features (in a hachured pattern) on a
transparency and then overlaid and registered it to the oil (greens) and gas (reds) AAPG
map of Oklahoma. The resulting combination is shown here:
Visually, the coincidence between hazies and fields does not appear strong. This was
supported by a spatial correlation analysis, which demonstrated there is no statistical
significance to the pattern distribution, i.e., the coincidence is random rather than
associative. In practical terms, there would be at least as much chance of striking oil by
drilling into points selected by throwing darts at the map, as there would be in drilling into
the centers of hazies. (That is not facetious: I did drop the overlay randomly several
times onto the AAPG map - a few hazies always landed on a few oil fields.) Based on a
quick field trip to the A hazy, the writer (NMS) believes hazy features are areas where
wind has blown away much of the soil fines, leaving reflective quartz grains behind. Of
course, if escaping hydrocarbons affect the soil, that may be degraded enough to foster
the wind removal.
However, at one locality designated as a hazy feature, the writer did find convincing
evidence of what appears to be distinct color difference attributable to hydrocarbon
alteration of red beds. In a dirt road, the reddish-orange of unaltered Permian rocks gives
way to a yellow-white color representing hydrocarbon "bleaching" as proposed by
EarthSat/Eason Oil. Here is a photo taken at that point:
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The Goddard geologists under my direction didn't perform these studies to discredit the
Eason Oil study, which provided some valuable insights into the discerning power of
space imagery for petroleum exploration and the potential shortcomings of the apparent
results. We did them to independently evaluate this approach and to inject caution into
any beliefs that this technique might become a panacea for finding petroleum.
5-11: Critique the Eason Oil study, devising if appropriate a defense of their
approach. In general, what do you believe to be the most effective use of remote
sensing in exploring for hydrocarbons. ANSWER
Our bottom line: "The Jury is still out" on making positive claims about oil and gas
exploration if based solely on the Eason Oil/EarthSat report.
At the time of the Anadarko study, several other investigators claimed to have found
similar evidence that appeared to indicate that leaking oil and gas reservoirs could
indeed be altering surface rock and soil. One that seemed to confirm this was the Beaver
Creek Oil Field in the Wind River Basin of Wyoming. Dr. Robert Vincent presented this
evidence, an MSS Band 5 (red) to 4 (green) ratio image in which a prominent oval
shaped anomaly (shown here in tan) coincided very closely with the outline of the field as
determined by subsurface drilling:
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The writer (NMS) visited this field while engaged in his Wyoming investigation work. The
area consisted of Lower Tertiary sedimentary rocks that were strongly dissected into
gullies. Many of these beds were reddish and could in themselves account for some of
the anomaly. A rather quick search for obvious signs of alteration by escaping gases or
fluids failed to find any convincing evidence. But the remarkable co-incidence of the 5/4
anomaly with the outline of the Beaver Creek field suggest that this may be a valid
example of the concept of alteration by petroleum compounds.
Landsat results in geological applications excited many in the petroleum and mining
industries. Various companies banded together as a consortium, starting in 1976, in what
became known as The Geosat Committee. Their avowed aims were along three lines: 1)
to share information and conduct studies using space imagery to search for petroleum
and minerals (mainly metallic ores); 2) to "lobby" NASA and Congress for a continuation
and expansion of the Earth-Observing Satellite program; and 3) to provide inputs in
determining and improving sensors in future satellites. One of their principal study sites
was the Patrick Draw oil field near the Beaver Creek field in Wyoming. (see summary
online at this website: Patrick Draw oil field). Hydrocarbons appear to be leaking as
gases at various points above the oil field. This map shows the results of a field study
(ground cored typically to depths of 3-4 m) that retrieved samples analyzed for propane:
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When the Patrick Draw field was overflown by an airborne UV sensor, this map of
fluorescence anomalies was constructed; these results seem to confirm detectability of
hydrocarbon-related gases at or above surfaces where leakage of the gases occurs:
Two discoveries stemming from the Geosat study of Patrick Draw are significant: 1) a
map of lineaments shows microseeps at several intersections, and 2) there is a distinct
geobotanical anomaly in and near Patrick Draw - sage plants are damaged, presumably
by escaping hydrocarbons, and this is detectable in hyperspectral imagery.
Unfortunately, key illustrations supporting this have not been made public.
Earth Satellite Corp. (now renamed MDA Federal, Inc), and another group, Earth Search
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Sciences, have continued to validate data obtained from sensors on satellites and
aircraft as potentially decisive indicators of subsurface oil/gas fields. This next diagram
summarizes recent thinking:
Airborne hyperspectral sensors that were flown over known hydrocarbon leaks (in some
settings, called microseeps) have found that an absorption feature near 2.31 µm (one of
several in the near IR) is very sensitive to the amount of a specific component of the
hydrocarbons. A ratio of two reflectance values on either side of that absorption feature
divided by the value of the decreased reflectance in the spectral curve at the feature's
low point enhances the detectability of the hydrocarbon and quantifies its magnitude.
This next image display shows an actual field case conducted jointly by the HJW
GeoSpatial, Inc, the Geosat Committee and Earth Search Sciences in which an oil seep
that corresponds to a specific pixel (red) in the Probe-1 hyperspectral scanner image
shows the 2.31 µm diagnostic anomaly (strong absorption bands at 1.4 and 2.0 µm are
related to other materials):
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Leaks of oil from fields below the ocean can serve both as an exploration indicator and
as a source of environmental damage. Prospecting for oil beneath the open ocean
requires some different techniques as well as use of some of the conventional land
methods. Oil seeps and slicks can remain intact on the surface and may be detectable in
Vis/NIR and radar imagery. The Earth Satellite Corporation has developed SEP - the
Seep Enhancement Algorithm - to bring out an oil signature using radar imagery. Here
are two examples:
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Oil slicks can be both natural or due to manmade oil spills. This EarthSat image shows a
slick off the coast from Kuwait as rendered in a natural color Landsat image.
Specialized remote sensing can monitor another aspect of petroleum withdrawal not
necessarily expressed as leaks. In time, as the oil is removed from pores leaving a
partially filled void, the rock units bearing the oil start to contract or crush inward into the
voids as support diminishes. This is commonly expressed by all the overlying units
pushing downward on the now compressed reservoir rocks, giving rise to progressive
surface subsidence. This lowering of elevation can be monitored by radar interferometry
(see page 11-10 This next illustration, made from ESA radar data, shows interferometry
rings, which can be computed into elevations, at the Lost Hills oil field in the San Joaquin
Valley of California. The field is subsiding now at a rate of about 3 cm (1.2 inch) per
month, with a cumulative drop since 1989 of 3 meters (10 ft). Subsidence is greater at
the two ends of this 1.5 x 6 km (~1 x 4 miles) elongate field.
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At the time of this writing (February, 2007) the intensity of the economic and political
aspects of the availability and costs of oil and gas as still the principal energy sources for
such multiple uses as transportation, heating, and plastics is at a "dangerously" high
level. Prices are rising everywhere because of OPEC decisions, rapidly growing markets
(e.g., China), and threats of cutting production (Iran's nuclear program). Alternate
sources of energy, including oil in non-conventional modes of recovery, are being
pushed. Two huge potential suppliers are Canada (tar sands) and Venezuela (heavy oil;
requires pumping in hot water to release the oil from its host rock). Estimates of available
oil from these types of deposits in Alberta, Canada approach, or may exceed, two trillion
barrels (Venezuelan heavy oil is at least one trillion barrels).
The Canadian oil sands were first discovered in the late 1700s. The sand units outcrop
at the surface in the northeast part of the province of Alberta but have a wider distribution
subsurface, as seen in this map:.
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The Cretaceous sandstones that contain sticky, near-solid bitumens (up to 20%) filling
interstitial pores have been called Athabasca Tar Sands or now more commonly Alberta
Oil Sands. Here is a surface photo of an outcrop rich in the blackish tar that pervades the
rock.
As seen by the Space Shuttle astronauts in 1989, the area along the Athabasca River
where surface stripping of the oil sands is active, is shown in the middle. The town of
Fort McMurray, which has since grown considerably in anticipation of greatly increased
production, appears to its south:
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Here are two aerial views of this main strip mine complex;
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The oil sands after surface removal are further broken up and then extracted from the
rock pores by subjecting the material to hot water and other chemicals. A barrel of thick
oil requires processing of about a ton of the oil sand. Here is a processing plant where
this is accomplished:
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For decades the cost of obtaining liquid products from the sands for further refining had
been too high to turn a profit. But that has now rapidly changed as prices of oil and
gasoline in the U.S. and worldwide climb in response to demand. This has convinced
various companies to set up greatly expanded operations. If stripping becomes
impractical, the cost of subsurface mining must be weighed against expected increases
in price and demand. In time recovery is likely to include underground mining. One plan
is to confine stripping recovery to the summer months and go underground when the
snow cover impedes surface mining. The reserves in Alberta are huge - comparable to
that known in the Arabian Peninsula. There may be enough tar sands in Alberta to place
Canada in "the driver's seat" in the 21st Century; for North America alone there could be
sufficient oil sand reserves to last a century. As of 2009, the U.S. gets 22% of its oil
(about 1.5 million barrels a day) from these Canadian deposits; China is becoming
another major customer.
The Canadian government is carefully monitoring and controlling the expansion of the oil
sand industry. Waste at the surface, as seen below, must in a reasonable time be
reworked to form a smooth surface and then replanted with trees and grass. Here is
where space imagery will play a leading role - determining that the reclamation
requirements are being met.
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Among other uses of remote sensing for applications related to oil and gas exploration
and production include: 1) monitoring pipeline location and possible breaks (leaks), 2)
monitoring environmental damage from drilling for oil/gas, 3) monitoring recovery of the
natural terrain after a field is no longer producing, and 4) producing land use/land cover
maps of a region where new or increased development is anticipated.
An example of item 2 is offered by this photo taken from the International Space Station.
It shows the barren ground patches around individual drilling sites and developed wells
in the West Texas Permian Basin - a major producer in the U.S.:
Astronaut photography is occasional and target-selective. Environmental effects in areas
immediately around drilling sites need more frequent monitoring. This SPOT-5 image
shows multiple sites near Carthage in west Texas. There appears to be almost no
adverse impact on areas surrounding the white scars that result from land cover clearing
at each site.
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This EO-1 satellite image also has environmental significance. It shows the markings
saturating the hills of southern California's Coast ranges at the Elk Hills oil field, which
first started producing in 1912 and is still active. It has yielded more than 1.3 billion
barrels of oil and some natural gas. For many years it was the kingpin of the Naval
Petroleum Reserve before being sold to Occidental Petroleum Co. in 1997.
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Regarding item 4 - land use mapping of a developed or developing natural energy-rich
region - is done in compliance with regulations for managing all of the resources. The
writer (NMS) participated in a singular example of this requirement, which engendered
an outcome of some notoreity. Here is the story:
Landsat-1 started to send back images in late July of 1972. The writer (NMS) was then a
co-investigator with Dr. Robert S. Houston and Dr. Ronald Marrs of the Geology Dept.,
University of Wyoming (Laramie) in the NASA-funded Wyoming Geology program. I
received the first images of Wyoming in mid-August and left at once for the field there. I
spent a week roaming the state to check out what I could relate between image features
and ground truth. Upon return to Laramie, Drs. Houston and Marrs and myself drove to
the state capital, Cheyenne, to meet with state officials about possible uses of Landsat
imagery in environmental and land use projects. A big one was in the offing - 8 million
dollars to prepare land use maps of the Powder River Basin. That basin is one of the
richest energy sources in all the U.S. - huge (and thick) deposits of coal, active uranium
mining, and some oil and gas productions. The maps were needed within 3 years.
The state officials decided to gamble and earmark $60000 for the University of Wyoming
to "try" to produce some preliminary maps using Landsat. The project began in
September. On January 13, 1973 the faculty and students who worked on Landsat
imagery presented a large (30 inches by 16 inches) folio with a series of maps - all
patiently colored by hand using student help - that addressed several themes. Most
important was the land use map, a portion of which is reproduced here:
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The State was so impressed, it accepted these folio maps as adequate in meeting its
multi-million dollar objectives. No further work was done.
A copy of the folio was soon sent to me. I too was impressed. I brought this copy down to
the Earth Observations program office at NASA Headquarter for the managers to see.
Their reaction was almost boisterous. This is just what they were looking for when they
went to the U.S. Congress in just a few weeks to an Appropriations Committee hearing.
The NASA chief, Dr. Len Jaffe, just commandeered (syn., confiscated) the folio and told
its story to the congresspersons. (Never got the folio back; students had to color another
one for me.) But a small price to pay to get the overall program in high gear.
Suffice to close this page with the remark that since the launch of ERTS-1, the petroleum
industry has found new oil and gas fields with the aid of space data and has developed
criteria from the images that continue to prove worthwhile in planning and conducting
exploration programs, which are leading to payoffs. Most of the successes have come by
using space imagery (as has been done before with aerial photography) in the tried-andtrue (conventional) way of using the pictures as base maps on which to analyze and plot
structural patterns and trends, often supplemented by recognition of stratigraphic units.
(Detection of surface alteration, while it happens sometimes, remains a rather rare event.
In sum, remote sensing aids in exploration for oil and gas by 1) providing overviews of
the regional geologic setting in which oil and gas is being sought; 2) helping to define
existing fold/fault structures; 3) demarcating linear features that are usually fractures
along which hydrocarbons migrate; 4) detecting alteration of rocks by escaping
hydrocarbons; 5) finding other signatures indicated by fluorescent anomalies in the UV
and compositional anomalies in the IR; 6) noting oil directly as leaks, spills, and seepage
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in the oceans/lakes or on land; and 7) observing environmental damage associated with
drilling, pumping, pipeline transfer, and refining of hydrocarbons.
Primary Author: Nicholas M. Short, Sr.
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