California Dreaming – Development Potential Assessment of a Major Offshore Field

Abstract

Abstract Inspired by the economic necessity of compressing the technical and economic evaluation time cycle, Mobil's conventional project planning evaluation process was reengineered. This new approach was successfully applied to a novel development plan for a major California offshore field. With 155 MMSTB of remaining recoverable oil, the South Ellwood Field is one of the larger oil development opportunities remaining in the continental United States. While portions of this field have been under production from Platform Holly since 1967, at least 65 percent of the recoverable original oil in place (OOIP) remains. Mobil's "Clearview" Development Project would have used extended reach drilling from shore. The extended reach wells would have horizontal depth to true vertical depth ratios of up to 5:1. The development proposal included abandonment of Platform Holly. This paper focuses on the creation of a development plan for this major California offshore field. A self-directed, multi-disciplinary team identified and resolved several technical issues that could have allowed the transformation of the existing 4500 STB/day field to one producing 20,000+ STB/day. Technical issues addressed for the heterogeneous Monterey Formation include; hydrodynamic tilt of the oil/water contact; identification and mapping of various lithologies using seismic, logs and regional geology; productivity variations between lithologies; recovery factor range, natural fracture orientation and effects upon horizontal well trajectories; horizontal well production forecasts using advanced decline curve analysis and reservoir simulation; and the use of a stochastically based methodology for quantifying production profiles at various confidence levels. The re-engineering of the technical study methodology put a premium on team work, communication, and integration. As a result of this re-engineering, the previously planned three year technical/feasibility study was completed in 6 months. This paper reveals how a self-directed, multi-disciplinary, multi-worksite team integrated solutions into a unified reservoir description and a cohesive strategy for future development.