Challenges of Lateral Transfer Pore Pressure Mechanism and its Impact on Non-Productive Time Deep water, Nile Delta, Egypt.

Abstract

Typically, the level of uncertainty in pore pressure would decrease for development wells that are drilled 400-900 meters apart after an exploratory discovery. In contrast to expectations, the uncertainty in pore pressure has not decreased for development wells drilled in the Raven field of the West Nile Delta offshore deep-water basin. Pore pressure related problems were attributed to differences in lateral pressure transfer mechanism in relatively thin and isolated sand units of Lower Serravallian epoch (Sidi Salim FM) along the study area. Authors bringing something fresh and original to the table of pore pressure that has not been done before within Nile Delta. Rapid sedimentation rate in the deep water of West Nile Delta basin in Egypt is one of the primary causes for the development of overpressure systems. In this setting, pore fluids unable to escape naturally during deposition. This study introduced other mechanism contribute to the overpressure zones, which is ignored while planning. The main purpose of this study is to investigate the impact of lateral transfer pore pressure mechanism on the differentiation between the shale and sand pore pressures and how to mitigate the associated kick /influx problems. Authors articulated best workflow and recommendations to minimize miss interpretation and risk of repeated non-productive time of studied wells. Shale pore pressure was derived from seismic, sonic and resistivity logs. Furthermore, 3D seismic volume used to estimate sand relief and finally sand lateral transfer pore pressure were estimated using centroid calculations methods.