Despite initial plans to develop Alpine with openhole unstimulated horizontal wells, propped stimulation treatments have proven to be extremely profitable. The first attempt increased rates 800%, with a stabilized 120-200% increase.
The Alpine field located on the North Slope of Alaska was developed using open-hole horizontal completions drilled along the maximum principle stress and dominant fault orientation (northwest/southeast). Open-hole completions were considered the best completion option based on rock mechanics, improved profile surveillance and cost. The original Alpine field development plan did not include hydraulic fracture stimulation based on the reservoir characterization. Well performance had proven to be economic in this Jurassic, marine sandstone without hydraulic fracturing, until drilling the CD2-37 well in 2003. The poor reservoir quality found in the southwestern edge of the field required stimulation to produce at economic rates. A hydraulic fracture treatment was performed resulting in a 200% production increase. Over the past three years, a stimulation program has evolved with improvements in candidate selection, performance and predictability. Future plans include continuing to stimulate candidate wells by incorporating horizontal completion technologies that are more conducive to multiple fracture technology.
This paper presents the evolution of the candidate selection process and a review of reservoir characterization as a result of the significant production improvements gained from hydraulic fracturing. We will also present how the Alpine full field model predictions have impacted the candidate selection process and discuss the stimulation design history that includes fracture fluid changes resulting from core analyses.
Author(s): Tim S. Schneider, David O. Uldrich, and Richard Hodge, ConocoPhillips Co.; Bob Barree, SPE, SPE, Barree & Assocs.; and Michael W. Martin, Schlumberger
Paper Number: SPE 106050