Exploring the Upside Potential of Ras El Ush - A Mature Producing Field, its Challenges and Solutions

Abstract

The Gulf of Suez is characterized by intensive normal faulting related to rifting of the Red Sea. The Ras El Ush (REU) field displays the same pattern. The field itself is bound on its eastern margin by large NW-SE oriented normal faults dipping NE (towards the Red Sea) and has dip closure to the west. However the nature of the northern and southern boundaries is unclear and they could be limited either by fault or dip terminations.The REU field has been producing since 1996 from the Nubia and Matulla formations and it currently has around a 26% recovery factor. Nubia and Matulla are isolated from the bottom water aquifer by tarmat layer that acts as a barrier. The field therefore exhibits depletion drive with a sharp pressure decline initially then a secondary gas cab expansion drive.The objective is to optimize pressure maintenance in the developed blocks either by using Gas Injection or Water Interjection and to evaluate the upside potential using an integrated reservoir management study approach and leveraging advance tools, technologies and best practices.Since the structure contains dipping beds (up to~50 deg) and faults, the conventional seismic does not help in interpreting reservoir units and dipping faults. Some of the vertical faults can be picked from seismic. In this case, it's critical to quantify the structural uncertainty due to lateral movement of faults and vertical movement of horizons, particularly near the oil water contact.