Alaska holds a significant position in the domestic energy supply of the United States, serving as a major source of crude oil since the late 1970s. The total quantity of oil within the state is complex, depending entirely on the criteria used for measurement. Alaska possesses a vast theoretical potential of oil resources, but only a fraction is categorized as immediately available for extraction. Understanding the true quantity requires distinguishing between what is geologically present and what is economically and technologically feasible to recover.
How Alaskan Oil Reserves Are Measured
The oil industry uses specific terminology to communicate the uncertainty and viability of underground hydrocarbons. The most certain measure is “Proven Reserves” (P90), which signifies a 90% probability that the actual volume recovered will meet or exceed the estimate. This category requires the oil to be recoverable under existing economic conditions, operating methods, and government regulations.
Moving down the certainty scale are “Probable Reserves” (P50), which have at least a 50% chance of recovery, and “Possible Reserves” (P10), which carry a 10% likelihood of successful extraction. These classifications are sensitive to changes in technology or market price, which can shift volumes between categories. Distinct from these are “Undiscovered Technically Recoverable Resources,” which are quantities of oil that could be produced using current technology, regardless of profitability or legal accessibility. The total amount of oil physically present in Alaska is far greater than its defined proven reserves.
Key Regions Holding Undiscovered and Proven Resources
Alaska’s proven reserves of crude oil stood at nearly 3.4 billion barrels at the beginning of 2023, making the state one of the nation’s largest reserve holders. The vast majority of this known oil is concentrated on the North Slope, the primary area of production. Future potential is suggested by massive estimates of undiscovered resources across the Arctic Alaska petroleum province, estimated to hold a mean volume of over 24 billion barrels of oil.
This resource potential is located within two geographically distinct areas on the North Slope. The National Petroleum Reserve–Alaska (NPR-A) is estimated to contain a mean of 10.6 billion barrels of oil, based on a 2002 assessment. Recent discoveries within the NPR-A, such as the Willow project, confirm the area’s continued potential for new reserves.
The Arctic National Wildlife Refuge (ANWR) also contains a significant estimated volume within its 1002 coastal plain area. A 1998 estimate concluded that this area holds a mean of 10.4 billion barrels of undiscovered, technically recoverable oil. These resource estimates highlight that the total volume of oil eventually produced depends heavily on future exploration, technological advancements, and policy decisions concerning protected areas.
Current Production Rates and Transport Infrastructure
Alaska’s oil production has seen a dramatic decrease from its peak, but it remains an important contributor to domestic output. Production peaked in 1988 at over 2.0 million barrels per day. By 2024, the state’s average daily production rate had fallen significantly, averaging around 421,000 barrels per day.
The entire system of oil transport hinges on the Trans-Alaska Pipeline System (TAPS), the sole means for moving North Slope crude oil to market. This 48-inch diameter pipeline stretches 800 miles from the North Slope fields south to the ice-free port of Valdez. Although TAPS was designed to handle throughputs of over 2 million barrels per day, its operational flow rate has fallen considerably with the decline in production.
The low flow rate presents significant operational challenges. Crude oil moving slowly through the frigid Arctic environment cools down, leading to issues like water dropout, ice formation, and wax precipitation within the pipeline. These issues necessitate continuous investment and mitigation efforts to maintain the pipeline’s integrity and ensure stable flow. The revenues generated from this flow rate fund approximately half of the state government’s operations, making TAPS an economic necessity for Alaska.