The giant fields on the North Slope of Alaska (combined Permian-Triassic/Lisburne pools at Prudhoe Bay and the Kuparuk River field) produce approximately 2 million BOPD and contain about 30 billion bbl of oil in place. This production rate amounts to almost one-fourth of the United States daily production. Because the reservoirs in these fields are complex and the stakes in efficient field management so high, the development geology of these fields presents a great challenge.

The technical challenge of managing these fields lies in the fact that secondary and tertiary recovery projects have been initiated soon after start-up to ensure maximum recovery. Thus, the development geologist has to recommend primary development locations while formulating a reservoir description without knowing the full areal extent and heterogeneity of the reservoirs. To support the waterflood and enhanced oil recovery projects, permeability pathways and barriers have been identified using sedimentological, log, and engineering data. Because structure also plays an important role in controlling fluid pathways, the fault geometries, fracture patterns, and detailed structure are being mapped using two-dimensional and three-dimensional seismic, well, and log data.

The management challenge of development work in these fields is keeping communications channels open among the development geoscience group and the reservoir, production, operations, and drilling engineers. The development geologists must communicate in engineering language not only to be able to understand the problems engineers

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face but also to be able to explain geologic concerns and solutions in terms understandable to engineers. Therefore, the geologic work in these fields is conducted at two levels. At the basic scientific level, interpretations of regional settings, depositional environments, facies distribution, and diagenetic and porosity trends are being carried out. At the applied level, this knowledge is integrated with engineering plans and modeling studies for projects such as delineation and infill drilling, well completions, waterflood, and enhanced oil recovery.

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