technology
From Exploration to Production on the North Slope
In the petroleum industry, there is an orderly progression of events from leasing to exploration to development. Oil field activities fall into three phases: exploration, development, and production.
In the petroleum industry, there is an orderly progression of events from leasing to exploration to development; in ANWR the progression is expected to take about 15 years or more. These long lead times result from the remoteness of the region, concerns for protection of the environment, and the regulatory requirements. The long lead time also means that in order to evaluate fully the ANWR Coastal Plain's petroleum resources so they might compensate (before the year 2010) for the continuing decline in domestic petroleum production, exploration must begin as soon as possible.
Oil field activities fall into three phases: exploration, development, and production. The intensity of activity and the level of potential impacts to the environment are significantly different from phase to phase.
Exploratory Operations. Exploration includes surface investigations by geological field crews, geophysical (seismic) surveys, and exploratory drilling. Planning and permitting for an onshore North Slope exploration well, which is typically drilled during the winter, can take three to six months. Drilling time varies depending upon the depth of the well and other factors. The work may be accom- plished without construction of permanent facilities. Roads and airstrips may be built of ice which will melt out by mid-summer.
Development. Once additional drilling confirms a commercial discovery, detailed engineering, economic, and environmental studies commence.
During this time, a proposed project undergoes a thorough regulatory review which usually includes preparation of an environmental impact statement.
Specific permits are required for most oil field activities including placement of fill, disposal of wastes, drilling activities, emissions from constructlor facilities, and so on. The highest level of activity occurs during the development phase as additional wells are drilled and camp and production facilities are constructed.
Production. Oil field construction activity wanes as production starts and the emphasis shifts from construction to maintenance activities. However, development drilling activity continues throughout the life of the field for secondary and tertiary recovery.