APPENDIX U: 

REASONABLY 

FORESEEABLE 

DEVELOPMENT 

SCENARIO FOR OIL AND 

GAS DEVELOPMENT 
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Jarbidge Draft RMP/EIS Appendix U 

APPENDIX U: REASONABLY FORESEEABLE 

DEVELOPMENT SCENARIO FOR OIL AND GAS 

DEVELOPMENT 

REASONABLY FORESEEABLE DEVELOPMENT SCENARIO 

FOR 

OIL AND GAS DEVELOPMENT 

IN THE 

JARBIDGE FIELD OFFICE 

Prepared by: Karen Porter, BLM Idaho State Office Geologist
 

Prepared by: ________signed copy on file______________ Date: _6/25/2009__ 

Reviewed by: Steven W. Moore, BLM Idaho State Office Geologist 

Reviewed by: _______signed copy on file__________ Date: _6/25/2009__ 

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Appendix U Jarbidge Draft RMP/EIS 

SUMMARY 

Based on the geology of the Jarbidge Field Office (i.e., the planning area), the lack of historical 

drilling activity, the lack of any historic or currently producing oil/gas wells/fields in south 

central Idaho and the surrounding area, and the lack of infrastructure to support oil and/or gas 

development, the potential for discovery and development of hydrocarbons in the planning area 

has been determined to be low. 

It is anticipated that very little to no oil and gas activity, aside from leasing and perhaps 

approving a few geophysical surveys, would occur during the life of the land use plan. However, 

in order to comply with the Supplemental Program Guidance for Fluid Minerals (BLM Manual 

Section 1624-2), this report describes the potential surface impacts associated with a minimal 

level of activity that could occur. Therefore, it is assumed that making the BLM-administered 

public lands in the planning area available for oil and gas leasing could result in the drilling of 

one to two exploratory wells during the next 20 years, for a total surface disturbance of up to 30 

acres (5 acres/drill pad + 10 acres/access road = 15 acres/drill site x 2 drill sites = 30 acres). It is 

assumed that one of the wells drilled would be capable of commercial production. Based on this 

assumption, a five-well field would be developed, disturbing an additional 60 acres. It is 

anticipated that two or three geophysical exploration programs would occur and that they would 

likely be conducted along existing roads or trails or by overland travel, thereby causing minor 

impacts to surface resources. These activities are likely to occur either in the northwest corner of 

the planning area or in the Cedar reservoir/China Mountain area. 

INTRODUCTION 

This report, describing a Reasonably Foreseeable Development Scenario (RFDS), accompanies 

the Oil and Gas Potential Report (BLM, 2009) prepared for the planning area. This report 

describes the anticipated level of oil and gas exploration and development activity associated 

with oil and gas leasing. These projections are necessary for assessing the anticipated impacts of 

oil and gas related activity in the Environmental Impact Statement for the Jarbidge Resource 

Management Plan (RMP); for determining which lands within the field office area will be 

available for oil and gas leasing; and for determining what stipulations may be necessary to 

attach to leases in order to protect the surface resources. These anticipated impacts are for the 

BLM-administered public lands described above during the next 20 years (2009-2029). 

DESCRIPTION OF GEOLOGY 

The geology of the planning area is described in detail in the Oil and Gas Potential Report 

prepared for the area (BLM, 2009). The planning area lies within the Snake River Plain 

physiographic province, which is entirely covered by Cenozoic volcanic and Quaternary 

sedimentary deposits. The planning area is dominated by the Owyhee Plateau, a broad volcanic 

upland considered to be a continuation of the eastern Snake River Plain. However, in the 

northern portion of the planning area, sediments of the Glenns Ferry Formation, which originated 

from Plio- Pleistocene Lakes Bruneau and Idaho, are found. These could theoretically contain 

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hydrocarbons, although none have been found. There are no known outcrops or exposures of preTertiary rocks in the planning area, and there is no direct or indirect evidence to indicate what 

types of rocks underlay the thick veneer of volcanics that cover the majority of the planning area. 

PAST AND PRESENT OIL AND GAS LEASING ACTIVITY 

A total of 251 leases have been issued at one time or another in the planning area (4.3% of the 

state total). Currently there are no active oil and gas leases in the area. Until recently, no parcels 

had been nominated for leasing in the planning area under the 1987 leasing process. In 2008, 

approximately 58,000 acres were nominated by a single entity. These parcels are situated in the 

Cedar Creek/ China Mountain area (T 14-16 S, R 13-14 E), in the southeast corner of the 

planning area. Leasing is being deferred on these parcels pending completion of the RMP/EIS. 

PAST AND PRESENT OIL AND GAS EXPLORATION ACTIVITY 

Three wells were drilled in 1950 for the purpose of exploring for oil and gas in the planning area 

- all located in the extreme northwest corner. No showings of gas or oil were encountered at any 

interval in any of the three wells. This is the only exploration activity that has occurred in the 

planning area. 

PAST AND PRESENT OIL AND GAS DEVELOPMENT ACTIVITY 

To date, there has never been any oil or gas production in Idaho, despite the drilling of 

approximately 150 wells in the state (Breckenridge et. al., 2006). 

OIL AND GAS OCCURRENCE POTENTIAL 

The majority of the planning area has a low potential for oil and gas occurrence throughout, as 

described in detail in the Oil and Gas Potential Report (BLM, 2009). No Paleozoic or Mesozoic 

marine sedimentary rocks, which could provide possible hydrocarbon source rocks consistent 

with USGS’s hypothetical Pre-Miocene or Older Tertiary Plays (Peterson, 1995), are exposed in 

the planning area, nor is there any evidence that such rocks exist at depth. The nearest exposures 

of Paleozoic sedimentary rocks are found 14 miles east of the planning area boundary, and those 

rocks are not known to contain hydrocarbons. Thick sequences of volcanic rocks in the planning 

area could conceivably conceal areas of favorable Paleozoic and Mesozoic rocks, but this cannot 

be determined, or even inferred, without adequate subsurface data. It is equally possible that 

plutonic rocks related to the Idaho batholith exist at depth and that the Paleozoic and Mesozoic 

rocks may have been eroded, faulted, or even displaced by plutonic activity. Therefore it is 

concluded that the oil and gas occurrence potential for the majority of the planning area is low, 

with a Level of Certainty A11. 

11 Level A: Available information is insufficient to infer level of potential; however, minimal potential cannot be 

ruled out. 

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Along the northern edge of the planning area, however, the sedimentary rocks of the Glenns 

Ferry Formation, some of which may contain organic matter, could possibly be a source for 

hydrocarbons consistent with USGS’s Miocene or Pliocene Lacustrine Plays. Although it is not 

likely, it is possible that basalt, which is vesicular and therefore somewhat porous, could be a 

reservoir rock where it is intercalated with the sediments. If a clay or shale layer were found to 

overlay the basalt, it could act as a seal to prevent the hydrocarbons from migrating to the 

surface, although no such formation is known to exist in the area. Also, no trapping structure is 

known to exist. Direct evidence of oil and gas presence in this area is lacking, as three oil and 

gas exploratory wells drilled in the Glenns Ferry Formation in the planning area found no 

“shows” of oil or gas (Youngquist & Kiilsgaard, 1951). While the potential for a discovery of 

petroleum resources in this area is slightly higher than the potential in the rest of the planning 

area, the potential is still considered to be low, with a Level of Certainty C12. 

OIL AND GAS DEVELOPMENT POTENTIAL 

Oil or natural gas production would occur in the planning area only if a significant oil or gas 

discovery is made. A significant discovery could be a 4,000- foot deep reservoir capable of 

producing a total of more than one million barrels of oil or a billion cubic feet of natural gas, or it 

could be a 15,000 foot reservoir capable of producing 500 to 700 million barrels of oil 

equivalent. 

Currently very little oil and gas infrastructure exists, making the costs associated with developing 

and producing a field higher than in areas of known production. The Williams’ Northwest 

natural gas pipeline runs through southern Idaho, parallel to Interstate 84 in the planning area. It 

is a common carrier, so it is required to accept gas input from various sources as long as quality 

standards can be met. In 2006, there was space available in the system, at least seasonally 

(Larsen, 2006). There are no other existing crude oil lines or refineries in southern Idaho. One 

small (8 inch) pipeline operated by Chevron Corp. transmits refined liquid petroleum products 

from the Salt Lake City, Utah, area into southern Idaho (Pocatello, ID), where the line roughly 

parallels the Williams pipeline to the west (Marconi, 2006). Since this line is for refined liquid 

products, it would not be available for wellhead oil or gas condensate products. 

Electric transmission lines are present across some of the planning area. These lines provide 

power to local residents and communities, but could possibly be used to bring electrical power 

needed for hydrocarbon processing facilities if such facilities were ever to be developed in 

southern Idaho. Large power needs may require supplemental or new lines to be constructed. 

Most of the planning area does not currently have roads that would support oil/gas exploratory or 

development drilling needs. While the planning area is relatively flat, many areas are extremely 

rocky and rugged, and road construction could be costly. Paved roads and improved gravel roads 

suitable for truck transportation of oil or liquefied gas products are limited in number and 

distribution. The only railroad line that could be used for liquid hydrocarbon product 

transportation is located just north of the planning area, roughly paralleling Interstate 84. 

12 Level C: Available information provides direct evidence to indicate the level of potential. 

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The lack of infrastructure to support oil and gas exploration and especially development or 

processing on or near the planning area would make these activities more expensive than in areas 

where the necessary infrastructure already exists. 

Limited reserve gas discoveries, such as marsh gas, are also unlikely to be developed in the 

foreseeable future in the planning area. Gas pipelines are necessary to move gas products. Small 

gas discoveries would not contain reserves sufficient to justify the investment in small diameter, 

high pressure lines that could, in turn, be connected to a larger, existing line. 

The overall probability of discovering and developing a producing oil and/or gas field in the 

planning area is considered to be low. This rating is based on the following factors: 

1) There has been a total lack of oil/gas industry interest in south central Idaho as 

demonstrated by the lack of leasing activity in the area during the past 15 years. 

2) No oil/gas seismic geophysical surveys have been conducted in southeast Idaho in the 

past 15 years on BLM-administered lands in the area. 

3) Exploratory drilling has been very sparse for such a large area, with no wells drilled since 

1950, further indicating industry’s lack of confidence in the area. 

4) No wells capable of economic production have ever been drilled in the entire state, let 

alone the planning area. 

5) There are no demonstrated oil or gas reserves in the planning area or adjacent areas. 

6) There is a general lack of infrastructure to support field development in southern Idaho. 

REASONABLY FORESEEABLE DEVELOPMENT BASELINE SCENARIO 

ASSUMPTIONS AND DISCUSSION 

The following assumptions for oil/gas leasing, exploration, and development in the planning area 

during the next 20 years are based on the oil/gas development potential described above, the 

regional geology, the historical drilling activity for southeast Idaho and surrounding area, 

topography, the existing access situation, and the requirements of the Supplemental Program 

Guidance for Fluid Minerals: 

- It is likely that 10 to 20 leases may be offered over the next 20 years, likely in the Glenns 

Ferry and/or the Cedar Creek/ China Mountain areas. 

- Two or three geophysical exploration programs would be conducted to help identify 

potential exploration drilling targets. 

- One or two exploration wells would be drilled on leases in the planning area. The wells 

would likely be 10,000-14,000 feet deep and would require the construction of a drill pad 

approximately five acres in size (approx. 500 by 500 feet). Each of the proposed drilling 

sites would be analyzed through the NEPA process, separate from the leasing analysis. 

Wildcat wells that discover only limited reserves of oil and/or gas are not likely to be 

economically viable because of the lack of existing infrastructure and would be plugged 

and abandoned. It is predicted that none of the exploratory wells would encounter 

hydrocarbons in sufficient quantity to justify production expenses and would be plugged 

and abandoned immediately. 

- Access to the drill pads may require up to two miles of construction/reconstruction. 

Access roads would require a 20-foot wide graveled running surface, with an average 

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disturbance width of 40 feet (4.85 acres/mile). Disturbance from two miles of road would 

equal about 10 acres. 

- Pad and access road construction would likely take one month; drilling operations and 

well testing would typically take from 1 to 4 months to complete; and reclamation would 

be completed within one year from when drilling is completed (assuming all wells are 

non-productive). 

- It is likely that about 5,000 to 15,000 gallons of water would be required per day, 

depending on down-hole conditions. Depending on the well locations, water sources in 

the planning area could be sought and applied for. Some wells make water, and disposal 

could become an issue if the water is saline. 

ANTICIPATED SURFACE DISTURBANCE DUE TO OIL AND GAS ACTIVITY 

The following phases of oil and gas exploration/development are typical in searching for and 

developing an oil and gas resource: 

1. Geophysical Exploration 

2. Drilling 

3. Field Development and Production 

4. Plugging and Abandonment 

The assumptions and scenarios that follow are based on historical drilling activity in the planning 

area, as well as the oil and gas potential for the area. 

Phase One: Geophysical Exploration 

Geophysical techniques are often implemented to identify subsurface geologic structures. The 

BLM reviews and approves geophysical operations on a case by case basis, and a lease is not 

necessary for such work. Gravity, magnetics, and seismic reflection are the most common 

techniques used. Both gravity and magnetic surveys cause very little disturbance as the 

instruments used are small and easily transportable in light vehicles or OHVs. These surveys can 

cover large areas and take only weeks to conduct. It is preferable to use existing roads, yet some 

overland travel is sometimes necessary. In addition, both gravity and magnetic surveys can be 

completed from aircraft, virtually eliminating surface disturbance. 

Seismic reflection surveys are the most commonly used geophysical tool. They require a seismic 

energy source and an array of receptors. Shock waves are created either through the use of small 

explosive charges or by vibrating or thumping the ground. Explosive charges are the preferred 

method and are used when access, road conditions, or population centers are not an issue. Two to 

six-inch diameter shot holes are drilled by a truck-mounted drill rig to depths between 25 and 

200 feet, where explosive charges between 5 and 50 pounds are detonated. Reflected seismic 

waves are recorded by a series of surface equipment along a 3- to 5-mile line. In situations where 

explosives are not used, the ground surface is mechanically vibrated using truck-mounted 

equipment. Both operations generally utilize a crew of 10 to 15 people with five to seven 

vehicles. Seismic surveys may be supported by aircraft. 

Based on the occurrence potential of the planning area, it is anticipated that two or three 

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geophysical exploration programs would be conducted to aid in identifying potential exploration 

drilling targets during the life of the plan. It is likely that ATVs or other rubber-tired rigs would 

be utilized for access, and no construction of roads would be required. Impacts from such 

exploration would be temporary (several weeks in duration) but somewhat intensive (i.e., 2 to 3 

vehicles/personnel in the area), such that seasonal restrictions may be necessary to avoid 

conflicts with some sensitive wildlife. 

Phase Two: Drilling 

Exploration wells are drilled in order to test geologic targets. On Federal mineral estate, an oil 

and gas lease must be obtained, and an application for permit to drill must be submitted and then 

approved by the field office. Site specific stipulations can be attached to the approved drilling 

permit. 

Temporary roads would likely be needed to transport and maintain the heavy equipment. Either 

existing roads would be improved or new roads would be constructed to accommodate the 

traffic. Typically, roads are constructed with a 20-foot wide graveled running surface with 

adjacent ditches and berms, for a total disturbance width of about 40 feet. 

Exploration holes range in depth from a few thousand feet to many thousands of feet, but are 

typically about ten thousand feet deep. Drilling to such depths requires large drill rigs and 

ancillary equipment. A drill pad three to five acres in size would be constructed, and may require 

cut and fill of the site to obtain a level pad. Topsoil would be removed and stored on site for 

reclamation. In addition to the drill rig, the pad may house a reserve pit, a mud sump, tool shed, 

drill pipe, fuel tanks, water tanks, generators, pumps, equipment storage, and temporary office 

quarters. 

Well drilling requires water. As much water as possible is recycled on site, yet about 5,000 to 

15,000 gallons of water may be needed each day depending on well conditions. Initially, water 

would need to be provided by some source, either wells or trucked in, to meet demands. Many 

oil or gas wells encounter water at depth when drilling for oil and/or gas, as it may be part of the 

oil and gas reservoir, and can be utilized when production is ongoing. Any water rights required 

would likely need to be filed in the name of the BLM. 

At the conclusion of well testing, if paying quantities of oil and gas are not discovered, the 

operator is required to plug the well according to Federal and State standards. Cement plugs are 

placed above and below water-bearing units with drilling mud placed in the space between plugs. 

When abandonment is complete, the site is reclaimed, which includes pad and road recontouring, 

topsoil replacement, and seeding with approved mixtures. Erosion control measures would be 

incorporated into the reclamation design as needed. 

The drilling site could be active for approximately one year, from the start of drill pad and access 

road construction; through drilling and well testing; to completion of plugging the hole and 

reclamation. 

It is anticipated that one or two exploration wells would be drilled on leases in the planning area. 

The wells would likely be 10,000-14,000 feet deep and would require the construction of a drill 

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pad approximately five acres in size (approx. 500 by 500 feet). Based on the road density in the 

planning area, access to the drill pads may require up to two miles of road construction or 

improvement. Surface disturbance from construction of up to two miles of road would equal 

about 10 acres. Total surface disturbance expected from drilling two wells would be up to 30 

acres. Each of the proposed drilling sites would be analyzed through the NEPA process, separate 

from the leasing analysis. 

Wildcat wells that discover only limited reserves of oil and/or gas are not likely to be 

economically viable because of the lack of existing infrastructure, and would be plugged and 

abandoned. It is predicted that none of the exploratory wells would encounter hydrocarbons in 

sufficient quantity to justify production expenses and would be plugged and abandoned 

immediately. 

Phase Three: Field Development and Production 

If a producible quantity of oil or gas is discovered, additional development wells would be 

drilled to confirm the discovery, establish the limits of the field, and drain the field. Depending 

on the field characteristics, well spacing may be from 40 to several hundred acres per well. 

The speed at which a field is developed is dependent on the anticipated productivity. It may take 

from one to three years to fully develop an oil or gas field. Large fields with several operators 

may be unitized to reduce surface impacts. In addition, directional drilling may allow for drilling 

more than one well per pad. 

During field development, the road system is greatly expanded. Temporary roads are usually 

improved to accommodate more traffic and increased duration of use. Improvements may 

include crowning, capping, and implementing additional erosion controls. New roads would also 

be constructed. Depending on well location and topography, a main access road is built with 

smaller secondary roads running to each pad. In addition to roads, other facilities may also be 

installed including power lines, tank farms, pipelines, oil/water separators, and injection wells. 

The production phase of an oil or gas field begins soon after discovery, and may coincide with 

development. Temporary facilities are often used initially, but as the extent of the field is 

determined, permanent facilities would be installed. 

Where oil and gas flow to the surface naturally, control valves and collection pipes are attached 

to the well head. Otherwise pumps are installed. Oil is typically produced along with water and 

gas. Separation facilities are constructed on site to remove water, carbon dioxide, and hydrogen 

sulfide. The oil and natural gas are then separated. Water, usually saline, is disposed of either 

through surface discharge, evaporation ponds or re-injection into the producing formation. 

If gas is present in economic quantities and a pipeline is located within close proximity, a 

network of pipelines would likely be constructed to collect and transport the gas. If not, gas 

would likely be re-injected into the reservoir. Oil would be collected in a similar manner and 

stored in tanks in a central location. Well operators would likely have service operations (e.g., 

cementing, logging, bits, testing, etc.) provided by established oil field service companies in 

Wyoming or Utah. 

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The producing life span of an oil or gas field varies depending on field characteristics. A field 

may produce for a few years to many decades. Commodity price, recovery technique, and the 

political environment also affect the life of a field. Abandonment of wells may begin as soon as 

they are depleted or wells may be rested for a period of time and put back into production. 

For the purposes of this report, it is assumed that one of the exploration wells would potentially 

encounter hydrocarbons in sufficient quantities to warrant field development. Based on this 

discovery, a five-well field would be developed. Disturbance for additional roads, pads, 

pipelines, and storage tanks may total over 60 acres. Depending on the size of the field, oil would 

either be trucked or piped to a refinery. 

Phase Four: Abandonment 

If paying quantities of oil and gas are not discovered, or at the end of the producing life span of a 

producing well or field, the operator is required to plug the well according to Federal and State 

standards and reclaim the disturbed areas. To plug a well, cement plugs are placed above and 

below water-bearing units with drilling mud placed in the space between plugs. When well 

abandonment is complete, equipment and surface facilities are removed, and the site is 

reclaimed. In a producing field, underground pipelines are often plugged and left in place in 

order to avoid re-disturbing these areas. Site reclamation includes pad and road obliteration and 

recontouring, topsoil replacement, and seeding with approved mixtures. Erosion control 

measures would be incorporated into the reclamation design as needed. 

CONCLUSION 

The probability of full field development and production occurring in the Jarbidge Field Office 

over the life of the plan is low. The existence or size of oil and natural gas reserves potentially 

found in the planning area is highly uncertain. Total surface disturbance associated with the 

anticipated oil/gas-related activity in the planning area as a result of making the lands available 

for lease equal about 90 acres during the next 20 years. This figure is based on drilling two 

exploration wells, one of which it is assumed will be productive. Disturbance is based on a drill 

pad (about 5 acres) + access road (about 10 acres) = 15 acres per drill site, x 2 wells = 30 acres 

for exploration drilling. If this activity does indeed occur, it is likely that well testing would not 

be favorable for production and the sites would be immediately reclaimed. Pad and access road 

construction, drilling and well testing, and reclamation would take an estimated 4-6 months, 

depending on well depth and drilling conditions encountered. Assuming that oil or gas resources 

are discovered at one of these wells, an additional 60 acres would be disturbed in that vicinity by 

the drilling of five additional wells, spaced at one well per 40 to 160 acres, depending on 

reservoir characteristics. This disturbance would not be reclaimed until the resource is depleted, 

which could take 1 to 10 years. It is anticipated that two to three geophysical survey programs 

would be completed during the life of the plan. This disturbance would be temporary, on the 

order of weeks, and would result in minor to negligible surface impacts. 

This RFDS meets the requirements of BLM’s Manual Section 1624-2 in describing potential 

surface impacts that could occur as a result of oil and gas leasing activity in the Jarbidge Field 

Office. 

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LITERATURE CITED 

BLM. (2009). Oil and gas potential of the Jarbidge Field Office. Boise, ID: USDOI Bureau of 

Land Management, Idaho State Office. 

Breckenridge, R. M., Gillerman, V. S., & Wray-Macomb, E. (2006). Oil and gas exploration in 

Idaho (Digital Web Map 81). Moscow, ID: Idaho Geological Survey. 

Larsen, L. 2006. Personal communication with Steve Robison, Caribou National Forest 

geologist. 

Marconi, B. 2006. Personal communication with Steve Robison, Caribou National Forest 

geologist. 

Peterson, J. A. (1995). Idaho-Snake River Downwarp Province (017). USGS National Oil and 

Gas Assessment, USGS Digital Data Series DDS-30, Release 2 (available at 

http://certmapper.cr.usgs.gov/data/noga95/prov17/text/prov17.pdf). 

Youngquist, W., & Kiilsgaard, T. H. (1951). Recent test drilling, Snake River Plains, 

Southwestern Idaho. Bulletin of the American Association of Petroleum Geologists, 

35(1), 90-96. 

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