Future Oil Production for the Alaska North Slope
May 1, 2001
Future Oil Production for the Alaska North Slope was prepared by the Reserves and Production Division, Office of Oil and Gas, Energy Information Administration (EIA) as part of the Domestic Oil and Gas Technical Support Program. The report presents a range of plausible production scenarios of combined crude oil, condensate, and natural gas liquids (NGL) hereafter jointly referred to as oil, for the Alaska North Slope (North Slope or ANS).
Production of oil (total liquids) from the ANS has declined from the 1988 peak rate of over 2.0 million barrels per day (MMbbl/d). As of this writing, the rate of production is about 1.1 MMbbl/d, accounting for 16 percent of total domestic production in 2000. Cumulative production through 2000 was 13.306 billion barrels (Bbbls).
In the absence of additional development 3.707 Bbbls remain to be produced from the currently on-stream fields. The inclusion of identified development, defined for the purposes of this report as projects to develop additional resources in discovered fields located near the existing production and transportation infrastructure, increases the ANS remaining recovery potential to 5.126 Bbbls.
Beyond identified development, exploration for and subsequent development of as-yet undiscovered ANS resources could add significant volumes to ultimate recovery. Three estimates of undiscovered technically recoverable resources that are representative of the range of uncertainty associated with the resource estimation process are used herein to provide a range of production scenarios for each of the ANS sub-areas analyzed. These estimates are based on the U.S. Geological Survey's (USGS) 95 percent probability (19 in 20 chance) of occurrence, mean (expected value), and 5 percent probability (1 in 20 chance) of occurrence values.
The production projections presented here were constructed in three layers beginning with the anticipated future production from currently on-stream fields. The second layer adds production from the anticipated development of identified fields and projects. The third layer adds projected volumes of production from technically recoverable undiscovered resources. The projections are based on historical performance, the reported anticipated performance of projects in the identified development category, and the application of current performance parameters to estimates of undiscovered resources.
The assumed minimum and maximum operating capacities of the Trans Alaska Pipeline System (TAPS) were limiting factors in determining minimum and peak production rates. Production projections based on performance history such as those presented in this report inherently embody past rates of technology improvement. The production possibilities associated with potential future gas-to-liquid conversion, gas liquefaction, and high viscosity crude production projects were not considered in this analysis.
The range of remaining and undiscovered Alaska North Slope oil is 6.1 to 13.3 billion barrels with a mean (expected) value of approximately 8.9 billion barrels. Ultimate recovery will range from 19.4 to 26.6 billion barrels. The mean ultimate recovery is approximately 22.2 billion barrels. Figure ES1 shows the production schedule for the mean estimates of undiscovered resources layered on the projected production of the currently producing and anticipated new development fields.
Identified development will stabilize ANS production at approximately 1.0 MMbbl/d until 2005, at which point decline resumes in the absence of new discoveries. If the identified development is delayed by factors such as low oil prices or environmental issues, production will begin declining before the year 2005.
Finding and developing the estimated mean volume of undiscovered resources in the ANS areas that are presently open to exploration and development activity maintains the production rate at approximately 1.0 million barrels per day until 2010. Production from the development of undiscovered resources in the National Petroleum Reserve-Alaska (NPR-A) is assumed to begin in 2010, causing production to remain close to 1.0 million barrels per day for another 5 years. The development of the estimated mean volume of resources increases the productive life of the ANS by approximately 10 years. Development of volumes larger than the mean estimate could increase production to approximately 1.4 million barrels per day.
Continued exploration for and development of undiscovered ANS resources is necessary to make a significant impact on production decline. Since minimum ANS production is not based on the minimum economic limits of individual fields, but rather on the sum of production from all producing fields compared to the assumed minimum pipeline operating limit, the timing of the future development will become critical as production declines to approach that limit. To the extent that development is delayed, technically recoverable oil resources in known fields will not be recovered. Further, when new development is added late in the producing life of the area, it might not be possible to produce the newest fields to their economic abandonment rate before the pipeline reaches its minimum operating limit and is shut down, in which event the remaining reserves in these fields also would not be recovered.