In the vast, frozen expanse of Alaska’s North Slope sits this months Analogue Spotlight, the Alpine Field. With over 50 square miles of subsurface resources accessed from a single surface pad, the Alpine Field demonstrates how modern petroleum development can balance large-scale production with environmental stewardship.

The field leverages cutting-edge extended-reach drilling and other innovations to minimize environment impact, making it possible to operate responsibly in an environment known for its ecological sensitivity.

Alpine extracts premium 40 °API gravity, low viscosity (0.45 cP) oil from two primary reservoirs: Alpine A and Alpine C. However, reservoir quality of the fine-grained sandstones is relatively poor. Across both reservoirs the average flow unit thickness is only 24 ft (Fig. 1), with porosity and permeability averaging 17.5% and 10 mD at Alpine A, and 20% and 15 mD at Alpine C.

Initially, a mix of horizontal and vertical wells were planned. However, reservoir modelling – supported by pre-production testing – showed horizontal wells alone would be more efficient and productive (due to good vertical connectivity and a favourable water/oil ratio of 0.1). Owing to the weak natural drive energy, water-alternating-gas miscible injection was initiated early with both horizontal producers and injectors in a line-drive pattern.

Early wells extended horizontally up to 6000 ft and, as drilling techniques improved, new and longer wells were drilled – some extending to over 32,000 ft in length (Fig. 2). In addition, the sandstone reservoir remains stable under production drawdowns, allowing open-hole completions, which reduce drilling time, lower costs, and minimize the risk of formation damage.

The success of extended-reach drilling at Alpine meant estimated recoverable reserves have steadily climbed. An original EUR of 250-300 MMBO rose to 429 MMBO and continues to grow – solid proof that innovation, efficiency, and environmental considerations can thrive together in modern oil development.