Northstar Drilling-Delivering the First Arctic Offshore Development

Abstract

Drilling oil wells on the North Slope of Alaska is not a new endeavor. Thousands of wells have been drilled over the past two decades in order to fill the Trans Alaska Pipeline. The majority of these wells have been drilled from a number of large drilling pads connected via a road network. Some of the newer developments have been drilled from remote pads accessible by fixed wing aircraft and ice road during the winter. So what is it that makes the Northstar Development stand out among all other drilling operations on the North Slope? It is the first Arctic Offshore Development that is not accessible by road for most of the year and does not have fixed wing air support. The implications of limited access to a 400' by 400' island are enormous. Successful completion of the first drilling season at Northstar is a significant milestone marked by detailed design and execution as well as pure determination. Many of the challenges were anticipated and accounted for while many others were not. The first Arctic Offshore Development delivered its first barrels of oil as per schedule on 2nd November 2001. Now comes the next challenge- drilling more for less to improve the profitability of this unique Alaskan project. Introduction Drilling oil wells on the North Slope of Alaska is not a new endeavor. Thousands of wells have been drilled over the past 2 decades in order to fill the Trans Alaska Pipeline. The majority of these wells have been drilled from a number of large drilling pads connected via a road network. Some of the newer developments have been drilled from remote pads accessible by fixed wing aircraft and ice road during the winter. So what is it that makes the Northstar Development stand out among all other drilling operations on the North Slope? It is the first Arctic Offshore Development that is not accessible by road for most of the year, and does not have fixed wing air support. The implications of limited access to a 400' by 400' island are enormous. Successful completion of the first drilling season at Northstar is a significant milestone marked by detailed design and execution, as well as pure determination. Many of the challenges were anticipated and accounted for while many others were not. The first Arctic Offshore Development is well on its way to delivery, but at a price. Northstar is BP's newest field development on Alaska's North Slope. The field is currently being drilled and production has just commenced from the man made Seal Island. Northstar is approximately 6 miles north of Prudhoe Bay in the Beaufort Sea (Figure 1). The island was built in approximately 40 feet of water on the remains of Seal Island, which was used for the original discovery/appraisal wells. The field encompasses roughly 60 square miles and contains an estimated 176 million barrels of recoverable reserves. Northstar will be the first development in Alaska that will be produced from both State and Federal Leases, with oversight from both the Alaska Oil and Gas Conservation Commission and the Mineral Management Service.

Assessing Sea Ice Trafficability in a Changing Arctic

“…An example of an ice road leading to an offshore drilling operation is illustrated in Figure 1. This road partly traverses sheltered ice, but is still influenced by offshore pack ice interaction, as is the road leading to Northstar Island west of Prudhoe Bay (Krieger et al, 2003) discussed here.…”

“…A key stakeholder need identified for the Northstar site is the need for continuous and extensive use of the ice road (Fig. 9a) throughout the 2.5-month operating season (Krieger et al, 2003), with minimal exposure to fractures or cracks that affect loadbearing capacity. This aim can be achieved either by routing the road through ice that has minimal occurrence of cracks and limited exposure to processes that generate cracks, or by placing the road on ice with confined occurrences of cracks that can be closely monitored and repaired as needed.…”