Execution of Offshore Projects: West Coast of Africa
Authors: Edwardes Robert J. 
Published: October 2008

The keynote address will provide a current overview of ExxonMobil's interests offshore West Africa, summarize the applicable suite of deepwater development technologies, describe current plans for ExxonMobil's first operated project in Angola Block 15, and discuss opportunities for common industry approaches to the unique development challenges in West Africa. This paper provides a framework for the address.

Introduction

In West Africa a new offshore oil and gas regime based on development of the deepwater plays along the Nigeria-Angola axis has now moved from a highly promising exploration infancy to reality. With several large Angolan and Nigerian projects now in the fabrication or design stages, the explorers' optimism has been confirmed. Within ten years, the West Africa region has the potential to mature to a scale that will rival the North Sea at its peak. This goal, however, will not be reached without considerable challenge.

Turning discovered oil and gas resources into future economic production streams will test the current limits of industry project execution tools and skills. Successful projects will require application of new or leading edge technologies, will employ high confidence execution plans based on recent lessons learned from similar past projects, and will involve considerable collaboration between and across oil companies, contractors and governments.

ExxonMobil in West Africa

ExxonMobil holds more acreage offshore West Africa than any other multinational oil company (refer Figure 1) and is well positioned to meet project execution challenges through its dedicated worldwide project organization, ExxonMobil Development Company (EMDC).

Deepwater Technology Selection

Clearly, appropriate technology selection is the first key to project success. In West Africa the character of the discovered resource, the metocean environment, and the availability of markets and infrastructure, are some of the factors that influence deepwater technology selection.

Conditions specific to West Africa which affect technology choice include:resource distributions ranging from broad, shallow reservoirs requiring multiple drilling centers, to deep and/or compact reservoirs accessible from a single surface drilling location;fluid variations ranging from low GOR crude to non associated gas, leading to a wide range of processing solutions;benign metocean conditions where optimum solutions may differ significantly from harsh environment areas, and more options may be considered;minimal pipeline infrastructure or local market for oil, leading to the need for storage and offloading in the field;absence of local market to absorb significant gas volumes, leading to the need for gas disposition solutions; andlimited local construction infrastructure, requiring complex international execution plans.

Limited industry experience in deepwater production also affects the view of applicable technologies. As of 1 January 2000, only seven oil or gas fields were being produced in greater than 1000 meters of water worldwide. This lack of experience means that the technology choices are by no means obvious. Meanwhile, by necessity the industry continues to search for innovative new approaches to try to lower the costs for development of deepwater West Africa reserves.