Placement of New Wells on a Mature Super-Giant Oil Field: the Importance of Appropriate Surveillance, Key Products and Risk Management

Abstract

First oil from the super-giant Rumaila field was in the early 1950s, with the majority of production to date coming from the clastic Zubair reservoir and peaking in the 1970/80s. In 2010 the Rumaila Operating Organisation (ROO) was formed as a joint venture between BP, the Chinese National Petroleum Company (CNPC) and the Basra Oil Company (BOC) with the aim of increasing production via large scale waterflood. A key part of delivering the development plan is appropriately describing the distribution of remaining hydrocarbons in multiple stacked reservoir units within the Zubair formation. The reservoir management team does this by integrating robust static geological description with dynamic production data to generate oil saturation maps for each of the reservoir zones and guide new well targeting and base management workover activity. To generate these maps a large scale and continuous surveillance program is required to monitor the movement of fluids in the reservoir. Since ROO formation drilling and surveillance campaigns have delivered >250 new wells, >350 PLT/ILTs, >500 saturation logs and >80 image logs. All this surveillance is incorporated, along with our geological understanding to build a picture of sweep in the reservoirs and where the remaining oil is situated. These maps are then used to identify the best value target opportunities and plan new wells. Given the scale of Rumaila, we release targets in batches and require an efficient hopper ranking process to high grade potential opportunities. Each batch contains a balanced portfolio of risk in order to deliver production forecasts but also gather surveillance to de-risk saturations & reservoir quality at future target locations. This talk will cover how these oil saturation maps are constructed, how they are used to target new wells and how risk and uncertainty is managed in the process in order to deliver the best value to the Rumaila development.

AAPG Datapages/Search and Discovery Article #90328 © 2018 AAPG Middle East Region GTW, Maximizing Asset Value: Integrating Geoscience with Reservoir Management & Facilities Optimization, Muscat, Oman, April 30 – May 1, 2018