--> Abstract: Pre-Development Reservoir Characterisation of the Ha'py Field, Nile Delta, Egypt, by J. W. Bailey, W. T. Bryant, M. G. Wallace, and W. S. Shaheen; #90923 (1999)
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BAILEY, J. W., W. T. BRYANT, M. G. WALLACE, and W. S. SHAHEEN, BP Amoco

Abstract: Pre-Development Reservoir Characterisation of the Ha'py Field, Nile Delta, Egypt

Located in the frontier development area of the outer shelf of the Nile Delta (Fig. 1), Ha'py Field is expected to become an anchor for future Nile Delta gas development. The field, discovered by Amoco and IEOC (AGIP) in 1996, is one of the more significant discoveries in the emerging Pliocene Trend. The main reservoir in the field, the A20 Sand, is an unconsolidated clay-rich sandstone in the Pliocene Kafr El Sheikh Formation. The field is exceptionally well imaged by 3D Previous HitseismicNext Hit data, thanks to strong amplitude effects associated with the top and base of the A20 gas sand and the gas/water contact (Fig. 3). In spite of the strong Previous HitseismicNext Hit signature, serious questions of reservoir quality were raised by the log and well test data acquired in the Ha'py-1 discovery well. Notable variations in Previous HitseismicNext Hit reflection character around the field raised additional questions about reservoir continuity, productivity characteristics, and resource size.

Prior to making the substantial investments necessary to develop the field, a reservoir characterisation study was established to address uncertainties about the resource size (OGIP), reservoir heterogeneity, and field recovery factor, and to determine the optimal number and location of development wells. The Reservoir Characterisation Study (RCS) was completed in five phases: (1) an appraisal drilling Previous HitphaseNext Hit, (2) an evaluation Previous HitphaseNext Hit, (3) a calibration Previous HitphaseNext Hit, (4) a modelling Previous HitphaseNext Hit, and (5) a simulation Previous HitphaseNext Hit.

The (1) appraisal Previous HitphaseNext Hit was designed to gather sufficient log and core data to allow understanding of the reservoir variability causing the Previous HitseismicNext Hit variability. Such understanding was necessary for the creation of a reliable model of Ha'py Field, which would serve as a basis for dynamic simulation and a tool for planning efficient field development. The appraisal plan was designed to sample the full range of rock types present in the field, by drilling in areas representing the extremes of Previous HitseismicNext Hit response variation.

In the (2) evaluation Previous HitphaseNext Hit of the project, the well data, logs and cores, from the appraisal wells were analysed. The internal Previous HitseismicNext Hit reflectors observed within the main reservoir interval were mapped to provide field scale reservoir fabric information.

The (3) calibration Previous HitphaseNext Hit represented an attempt to relate log responses and Previous HitseismicNext Hit expression to rock and fluid properties. Petrophysical evaluation of log, core, and test data acquired through appraisal drilling included correlation of log responses to rock and fluid properties, the identification of flow units, and the identification of rock types. Core-derived log permeability formed the basis for the reservoir flow-unit tie to Previous HitseismicNext Hit amplitude reflections (Fig. 2). Four rock types were determined by subdividing the dynamic range of reservoir porosity and permeability into four regions. Appropriate capillary pressure and corresponding relative permeability curves were assigned to each rock type to provide gas saturation and fluid flow characteristics based on laboratory measured data. It was found that the flow units identified by petrophysics could be mapped reasonably well at the Previous HitseismicNext Hit scale due to the thick-bedded nature of the internal reservoir layers. This allowed the Previous HitseismicNext Hit data to extend the stratigraphic flow units away from the existing well control and provide a detailed layering scheme for the reservoir model.

In the (4) modelling Previous HitphaseNext Hit, a geologic model was developed (prograding slump fan complex), based on rock properties and Previous HitseismicNext Hit geometries. A multi-layered reservoir model was built based on the geologic model and the Previous HitseismicNext Hit mapping of flow units identified by the petrophysics.

Finally, in the (5) simulation Previous HitphaseTop, a dynamic simulation of reservoir performance of the multi-layered model was performed, allowing the testing of various scenarios of development well number and placement. The porosity, absolute permeability, relative permeability, and capillary pressure relationships established by petrophysics were inputs to the reservoir simulation. In all model cases the development of the field was deemed economically viable, and a development plan calling for six initial producers is now under construction. 

AAPG Search and Discovery Article #90923@1999 International Conference and Exhibition, Birmingham, England