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AREAS REQUIRING FURTHER STUDY
Although the environmental, technical and economic feasibility of an arctic pipeline are considered to have been demonstrated, it is realized that some further work and research remains to be done, and detailed designs and plans would have to be prepared. The principal areas of research (as differentiated from more routine engineering effort) in which further investigation is needed are suggested below.
1. When a specific route has been established for an oil pipeline, it may be necessary to gather further basic data in the field in order to assess and prepare a comprehensive statement on environmental impact.
2. Sociological developments in the areas affected by the pipeline should continue to be studied.
3. Further research is needed to improve the method of predicting ice content in soil, and the development of a terrain classification system. This work is now in progress.
4. More comprehensive slope-stability data are needed. This work too is in process.
5. The mathematical model used to predict thermal regimes will be modified to include additional research data as its becomes available.
6. Present seismic information is somewhat incomplete. More wo ld be desirable, and a program to that end is contemplated.
The design criteria for this study are based on series or parallel, and driven by aircrafts sound engineering principles applied to a particularly generator-power turbine combinations. Son 30 demanding environment, and meet the require- has been made of the alternative of using eines ments of all applicable government regulations. driven pumps supplied from hydro-electric deres Because of the extreme conditions, this line is de- ment. Maximum operating pressure for the signed to be of higher quality and reliability in wall, 48"-diameter pipe of 65,000 psi MSYS, - 13 almost every respect than the minimums recom- pounds per square inch. mended in existing codes and standards. Hydraulic Pump stations and terminals were designed i and thermal gradients for the pipeline at 1.8 MMBD maximum reliability and self-sufficiency. Electron throughput are shown in Exhibit 11.
for the stations would be supplied by genere Large differential temperatures (up to 170°F) on the site. Each station would have standby gese between the warm oil and the cold environment tors and pumps, plus emergency equipment. Ces would impose additional stresses on the pipe when puterized monitoring and control of oil-flos pozic installed. These stresses were calculated and con- be programmed with provision for safe and specs sidered in the design. The necessary thickness of the shutdown and isolation in emergency. Ouatu pipe wall (up to 0.6") for the operating pressures would be provided for permanent maintenance of anticipated, and the insulation necessary for the The station buildings and equipment would be temperature conditions had to be decided after de- elevated on gravel pads to insulate the permatas tailed analysis. The difficulties that might be caused A complete fire protective system would be an e by increased oil viscosity due to cooling after shut- portant part of each station and terminal. down, were thoroughly analyzed by the use of a To allow continuous operation, tanks of a computer program designed for this purpose, and quate capacity must be provided at Prudhoe Bry provided for in the insulation design. For above- These tanks would be elevated on gravel foundation ground installation, a continuous zig-zag pile-sup- above the permafrost. Storage tanks at Edmonica ported configuration was decided on, with ground would be the responsibility of the oil receiver. Al anchors at points requiring full restraint (Exhibit 12). terminal and station areas would have a controlled
The initial design capacity of the pipeline would drainage system to trap and recover any oil. be 800,000 barrels per day, with 10 pump stations A high quality and dependable communication each having an average brake horsepower of 11,080. system is vital to this line. A temporary system A typical layout of a far northern station is illu- would be installed during the construction phase strated in Exhibit 9. The station constructed schedule to be superseded by a highly sophisticated, auto is based on a throughput increase over 6 years to mated supervisory-control system when operation 1.8 million barrels per day, requiring 22-pump began. Emergency fail-safe provisions would be in stations with an average of 35,000 horsepower each. corporated into the system. The computerized 003The line could be expanded to a capacity of 2.5 munication system would monitor and control zu million barrels per day with 46 pump stations of flow, pressure and other operating conditions, and 42,000 horsepower each, or by laying additional gather and store information on the condition of sections of pipe in parallel. Overall pump efficiency machinery, inventory of parts and other useful date. was estimated at 85 percent.
The same buildings. towers, and other facktin The pumps selected for the study were double- would be used for both systems to minimize both suction horizontal split-case pumps, arranged in cost and environmental disruption.