The Bonga 4D - Shell Nigeria's First Deepwater Time Lapse Monitor

摘要

The Bonga Main field was discovered by Shell Nigeria E&P (SNEPCO) in 1995 and is located 120 km offshore Nigeria at water depths of 800-1200m. First oil production started in November 2005. Bonga is Nigeria's first deepwater discovery. Oil production at Bonga is from 4 stacked reservoirs through several producer/injector well-pairs. A 4D Time Lapse Feasibility Study was completed and predicted that the Bonga reservoirs would be conducive to generating robust time-lapse signals of the fluid movements. A 4D time-lapse seismic monitor survey was acquired over Bonga in Q1-2008, to aid in the management of the early production life of the reservoirs. This monitor seismic data, together with the pre-production (year-2000) baseline, were processed by Western-Geco. In July 2008, an intermediate ultra-fast-track dataset was delivered to the Asset Team. This paper will give an overview of the Bonga 4D Project, including the feasibility study, the monitor acquisition and seismic processing, and the early interpretation results of the 4D Seismic over several Bonga Reservoirs. In addition, the impact on our current understanding of the Bonga reservoirs and the value that Time Lapse Monitoring has delivered will be discussed.