Adding Value Through Near-Field Exploration Driven by 3-D Acoustic Impedance Conditioned Reservoir Modeling: An Example from a Mature Gulf of Suez Carbonate Producing Asset, Ras Fanar Field, Egypt

Vaughan, Richard D., RWE-Dea, Cairo, Egypt

Discovered in April 1978, Ras Fanar Field in the Gulf of Suez of Egypt has produced approximately 96 MM STB (January 2005) oil from Middle Miocene coralline algal buildups and laterally intercalated dolomitic layers within sabkhas deposits. This paper presents a simple but effective 3D reservoir modelling workflow which used acoustic impedance (AI) data and its relationship to effective porosity as a deterministic 3D modelling parameter (“porosity-facies”) rather than the more traditional facies based approach.

In 2002 a seismic conditioned model for the Ras Fanar Field was completed and a num­ber of infill wells were successfully drilled within the main field which mediated the produc­tion decline of the field. Based on the model a number of higher risked drilling targets were subsequently identified to the west of the main field. The westward extension of the Ras Fanar field was confirmed by well RF-B10. This well encountered the original field oil-water contact at 2450’ TVDss despite 20 years production. The contact is thought to be in part influenced by secondary gas cap expansion which has “pushed” the oil column back to the original spill point.

A number of deviated wells have been positioned to target a series of amalgamated lagoonal patch reef bodies which formed on the landward side of the main Ras Fanar cor­algal reef complex. Up to January 2005 three near-field exploration wells have been success­fully appraised the western extension of the Ras Fanar field and a further two wells will be drilled during 2005. The target locations have been optimised so that the wells penetrate the reservoir with a standoff from both the gas-oil and oil-water contacts.

The model will be updated to incorporate the new well data during 2005 and the share­holders of the Ras Fanar Field will continue to use it for future well planning.