Project Overview
PND has been involved in multiple iterations of the Liberty Island project for BP Exploration Alaska (BPXA), from feasibility studies and conceptual designs in the late 1990s to comprehensive design engineering and construction support services for Satellite Development Island (SDI) in the mid-2000s and subsequent additional development designs, planning, permitting support, and cost estimating as an offshore island configuration. BPXA proposed developing a drilling/pumping island in 20-foot-deep waters to support oil extraction from this remote site with estimated reserves of over 100 million barrels of oil. This unique project required a stable structure for supporting heavy oil production equipment while withstanding harsh Arctic conditions, wave erosion, and extreme ice overtopping.
PND designed an OPEN CELL SHEET PILE™ (OCSP™) dock for the proposed development in 1997 and was responsible for site civil work, including oil/water separators, facility and pipelines foundations, helipad, and seawater intake structures. PND developed design ice criteria for bridge foundation and superstructure alternatives to accommodate year-round access for pipelines and oilfield support vehicles. PND developed conceptual designs and cost estimates for roads, bridges, pads, and material sites in 2005 for potential extended-reach drilling pads to access the Liberty hydrocarbon reservoir. PND ultimately provided design and construction support services for a 22-acre expansion at SDI, which included a 2,000-foot OCSP bulkhead module-offload facility and 860,000 cubic yards of gravel for accommodating an extended-reach drill rig (45,000 feet), mancamp with over 200 piles, 10-mile-long ice road, boat launch ramp, erosion protection, and access bridge rehabilitation.
Our Role
- Arctic Engineering: designed innovative solutions for harsh Arctic conditions such as extreme erosion and ice overtopping events in the Beaufort Sea
- Geotechnical Engineering: managed a geotechnical investigation to characterize the SDI expansion area and identify a developable gravel source
- Hydrology & Hydraulics: performed hydrological studies for two of the three originally proposed drilling sites, including metocean analysis, corrosion studies, field hydrology, and bathymetry in support of the SDI expansion design
- Contract Administration & Construction Support Services: supported permitting for the island expansion and numerous civil infrastructure components, providing comprehensive engineering and construction support for a 22-acre offshore island expansion
- OPEN CELL SHEET PILE: designed an OCSP dock and an OCSP bulkhead module-offload facility
Adapting to Arctic Extremes with Durable Solutions
PND’s strategic approach to the Liberty project focused on developing strong, cost-effective solutions that could withstand extreme Arctic conditions found on the North Slope of Alaska. PND designed a 150-foot by 160-foot OCSP™ dock for module offload and support of heavy oil production equipment while resisting the impact of ice overtopping events in the Beaufort Sea.
PND designed a 2,000-foot OCSP perimeter loading dock and erosion protection for the SDI expansion, providing robust protection, lower cost, minimized maintenance needs and environmental impact, and reduced gravel requirements and seabed disturbance. PND’s design included pipe rack foundations, insulated conductor piles, material source development/rehabilitation, ice-road design, personnel camp facility foundation design, and an oil spill response boat launch ramp. PND designed superstructure upgrades for the Sagavanirktok River Bridge, including new pile caps, girders, and decking to accommodate heavier loads and address ongoing fatigue issues without modifying the foundation system, improving the schedule by more than 12 months and avoiding all environmental permitting by eliminating upgrades below water. The project’s success was driven by PND’s arctic engineering expertise, understanding of the owner’s needs, and experience creating innovative, efficient, and scalable solutions for harsh environments.
Pounds per Square Foot
capacity of Liberty’s MOF dock face
Cubic Yards
amount of gravel used in the SDI expansion
Feet
water depth in which the island was constructed
