Characteristics of Microzonation Modelling in Reservoir Evaluation -- Case Study: Ras Budran Oil Field

By

Samir A. Aal¹, N. A. Fattah², N. El Defrawy¹

(1) Suez Oil Company (SUCO), N/A, Egypt (2) Cairo University, Cairo, Egypt

Suez Oil Company (SUCO) operates Ras Budran oil field located 4 km off the eastern coast of the Gulf of Suez. It was discovered by Well RB-B1 (EE85-1) in 1978 and come on-stream in February 1983. The trap is tilted horst block.

Although areally small (2 X 2.5 km), the trap involved several stacked pay zones extended over about 2000 ft to an original oil-water contact. The main reservoirs involve Nubian “C & D” (Carboniferous and older), and “A & B” fluvial-shelfal sands (Carboniferous - Early Cretaceous), with minor contribution from Raha sands (Cenomanian).

The verification of the above mentioned macro-layers indicate the difficulty to understand the reservoir performance and its potentiality. Furthermore, the attempts to place these reservoir units into a sequence stratigraphic framework were failed because of the lack of available detailed sedimentological and paleontological data, plus the poor quality of seismic data over the field.

The purpose of this study has been to construct a detailed micro-multi zones (flow units) geological and petrophysical model of the reservoir in the field. This has been done using all available geological, petrophysical and core data integrated with engineering data and geostatic mapping of the micro zones properties.

This microzonation model can then be used, as a part of the input required to construct a reservoir model (static model) for mathematically simulations (dynamic model). This approach has been used in the field understudy where it got a reliable history match as well as better understanding of the fluid movement.