Waterflood Opportunities In Block 0, Cabinda, Angola
Authors: Flaherty G.M. , King G.R. , Malone T.R. , Domingos F.M. 
Published: October 2008

The expansion of secondary recovery projects in mature, offshore 'producing areas presents a variety of technical and project management challenges, The Block 0 Concession, Cabinda, Angola is operated by Cabinda Gulf Oil Company on behalf of Association partners, Sonangol, Chevron, Elfand Agip, The partners are pursuing water flood expansion projects in 15 reservoirs at 10 fields, with potential incremental reserves of500 Million Barrels. The project has been accelerated by application of lessons learned from existing floods and by the use of Chevron's Project Development and Execution Process (CPDEP). The CPDEP Process has been successful in prioritizing projects, obtaining partner consensus, ensuring internal alignment and fast tracking key program elements through parallel work processes. The multidisciplinary CPDEP team has recommended a phased development approach to maximize asset value by leveraging existing reservoir knowledge and eXlstll1g infrastructure. This paper is divided Into two mall1 sections, In the first section, we describe In detail the ongoing resen10ir management programs used in two existing water floods in the Block 0 Concession. In the second section, we discuss the CPDEP process and outline how it is used to extend the Concession's existing water floods to resevoirs which are currently on primary production.

Introduction

Since 1968, the Cabinda Association has produced 1.7 Billion Barrels of oil from Area A, Block 0, Cabinda, Angola (Figure 1) The resource base of 11 Billion barrels OOIP is distributed within 16 offshore fields and 44 reservoirs. Based on the success of secondary recovery projects at the Takula/ Numbi (1990-91), N'Sano (1994), and Kungulo (1996) Fields, the Association of Sonangol Chevron, Elf and Agip is pursuing additional water floods in 15 reservoirs at 10 fields, with potential incremental proved, probable and possible reserves of 500 MMSTB (Figure 2) The development of new water flood opportunities will require capital investments of approximately 1 Billion USD for new platforms, wells, and facilities over the next decade

Accelerated development of the remaining water flood opportunities presents a variety of technical and project management challenges. Leveraging reservoir management lessons learned from the existing water floods is critical to the success of the expansion effort.

For existing water floods. a proactive reservoir management strategy, including: reservoir characterization, reservoir monitoring, flow simulation, and project implementation is the foundation for the continued success of these floods. In addition to reservoir management issues, field and infrastructure constraints must be addressed within the context of optimizing existing operations concurrently with increasing capacity.

For future water floods, a multidisciplinary team has applied Chevron's Project Development and Execution Process (CPDEP) to mature new water flood assets from potential to find projects. CPDEP consists of five stages, including:Asset classification,Project selection,Development plan selection,Project Implementation andOperations. evaluation and enhancement.

CPDEP hasproven to be an effective tool for prioritizing opportunities, assessing critical risk elements and reducing project cycletime. Based upon asset technical maturity,