Life Of Field Seismic In The Deepwater BC-10 Phase 2 Development, Brasil

Abstract

Abstract This paper presents the first full field ocean bottom life of field seismic system (LoFS) deployed by Shell, the deepest deployment of this technology in the world and the first installation tied back to a turret design FPSO. From final investment decision to installation was only 17 months. The system comprises 100 km of ocean bottom cable in 14 lines spaced 400 m cross line and 4 component sensors spaced 100 m inline. The cables are connected via 11 km of backbone cables to the existing umbilical termination assembly which supplies power and communication from the FPSO. The system permits the acquisition of high quality, highly repeatable seismic surveys. The topsides equipment installed on the FPSO can be operated remotely from Houston which removes the requirement for specialist staff to be located on the FPSO during surveys. Several alternative systems were considered prior to the investment decision including both electrical and optical systems. The base survey was completed November 2013, prior to first water injection and the first monitor survey was obtained during June 2014, only 3 months after first water injection. Shell's Marine Imaging Group provides the complete processing services for LoFS data. This builds on their 4D processing experience developed for Ocean Bottom Node (OBN) surveys. Experience gained during processing of the base line survey contributed to a very rapid delivery of quick look 4D seismic volumes to the operations and development teams only 3 weeks after completion of the monitor survey acquisition. Despite the short duration between start of injection and the first monitor survey (3 months) significant information was obtained confirming no out of zone injection, water injection along the entire length of all laterals, location of early water production in 2 wells and no water fingering observed from injectors to producers in this high viscosity oil reservoir. These observations supported the decision to operate the field at higher rates with current field production and injection rates above expectation providing early economic benefit from this novel system. The second monitor survey was acquired January 2015 with results available after the submission date of this paper.