Trans Alaskan Pipeline Matt Penny Mike Shirley

Introduction Trans Alaskan Pipeline Runs from Prudhoe Bay to Valdez 800 miles long 3 years build $8bn total cost Ave 860,000 barrels per day

Geological research Soil analysis –3,500 boreholes –15,000 soil samples Earthquake protection Permafrost Physical obstructions Thermal expansion Avalanches

Thermal expansion Change in pipe length due to variations in crude oil temperature Zig Zag formation allows for expansion and contraction of the pipe Pipeline anchored, so cannot expand lengthwise, but shifts laterally on supports

Above ground solution 420 miles above ground Specially designed vertical supports solve problem of undesirable thawing –Heat pipes containing anhydrous ammonia remove ground heat –Heat transferred to radiators

Below ground solutions Why go below ground? –Highways –Environment –Avalanches Conventional pipeline –Thaw stable soils –Pipeline buried –Sacrificial anodes, zinc ribbons Non-refrigerated –Thaw unstable soil –Pipeline insulated and buried Special burial, refrigerated –Thaw unstable soil –Pipeline insulated and refrigerated using chilled brine to maintain soil in stable frozen condition

Earthquake protection Crosses 3 fault lines –Denali –McGinnis Glacier –Donnelly Dome Designed to withstand 8.5 Richter scale Earthquake monitoring at pump stations Pipeline built in zig zag formation above ground to protect against earthquakes

Summary Pipeline is a very important part of the oil business in Alaska Tankers do not have to travel around Alaska peninsular Implemented the solutions to the problems Alternative to underground burial of pipe –All above ground –Unrealistic – bridges, affected by wind