Abstract

A joint study integrating geological and engineering data was undertaken to locate infill wells and to optimize the injection pattern in Hayat-Yasser, Kenz and Salam fields in the western desert of Egypt. The focus of this work was the Cretaceous Bahariya and Abu Roash "G" formations which are sedimentologically described as estuarine to shallow-marine sandstones deposited in a mixed clastic-carbonate ramp setting.

All major seismic surfaces were remapped using pre-stack time-migrated data. A detailed sequence-stratigraphic framework based on core description and petrophysical analysis provides the static reservoir framework. These geologic data are incorporated in a detailed 3D geological model, which forms the basis for all structural and reservoir mapping. Pressure and production data were analyzed within this framework, in order to identify potential infill and recompletion opportunities as well as potential improvements in changing water-flood pattern from peripheral to internal and to dedicated injection.

Introduction

A reservoir characterization study was done by multi-disciplinary team from Khalda-Apache staff. It integrates Seismic, Geology, Petrophysics and Engineering data to identify development opportunities. Data incorporated in this work includes more than 200 wells and about 5000 ft of cores (Figure 1). This work covers Salam, Salam North, Hayat-Yasser & Kenz fields, shallow reservoirs depths; ARG, UBAH, ULB50 and LBAH. At the end, infill drilling locations were identified, recompletions opportunities were recognized and waterflooding were optimized.

Sedimentology

The overall section of ARG, UBAH and LBAH (Figure 2)is a transgressive successions punctuated by surfaces of erosion and mainly dominated by Estuarine and restricted marine deposits. Marine influence is commonly marked by increase in bioturbation and significant proportion of glauconite, fish teeth and bone fragments. Erosional surfaces (in UBAH) are defined by Glossifungites and ichnofabric1. It is characterized by lagoonal bay, tidal flat, vegetated swamps and marshs type facies. Lagoon bay is defined by Oysters, shells and bivalves and tidal flat defined by woody material and rootlets and vegetated swamp and marsh defined by rootlets and extensive burrows2 (15 cm in some cores). In general, cores from the north exhibit increasing marine character at Tut-9, Salam-5 & 35 compared to wells in the south at wells at Y-3, H-8 & Shr-4.

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