Proved undeveloped reserves

As of December 31, 2014, TOTAL’s combined proved undeveloped reserves of oil and gas were 5,817 Mboe as compared to 5,852 Mboe at the end of 2013. The net decrease of 36 Mboe of proved undeveloped reserves is due to the addition of 648 Mboe of
undeveloped reserves related to extensions and discoveries, the revision of -105 Mboe of previous estimates (partly resulting from a negative price effect in Canada), a net decrease of 153 Mboe due to acquisitions/divestitures, and the booking of 425 Mboe proved undeveloped reserves to proved developed reserves. In 2014, the cost incurred to develop proved undeveloped reserves (PUDs) was $18.5 billion, which represents 83% of 2014 development costs incurred, and was related to projects located for the most part in Angola, Australia, Canada, Gabon, Nigeria, Norway, Republic of the Congo and United Kingdom.
Approximately 49% of the Group’s proved undeveloped reserves are associated with producing projects and are located for the most part in Canada, Kazakhstan, Nigeria, Norway, Russia, and Venezuela. These reserves are expected to be developed over time as part of initial field development plans or additional development phases. The timing to bring these proved reserves into production will depend upon several factors including reservoir performance, surface facilities or plant capacity constraints and contractual limitations on production levels. The remaining proved undeveloped reserves correspond to undeveloped fields or assets for which a development has been sanctioned or is in progress.
The Group’s portfolio of projects includes a few large scale and complex developments for which reserves have remained proved undeveloped for more than five years or the Group anticipates that it may take more than five years from the time of recording proved reserves to the start of production. These specific projects represent approximately 18% of the Group’s proved undeveloped reserves and include deep offshore developments in Angola, Nigeria and the United Kingdom and development of oil sands in Canada. 
These projects are highly complex to develop due to a combination of factors that include, among others, the nature of the reservoir rock and fluid properties, challenging market and operating environments, and the size of the projects. In addition, some of these projects are generally designed and optimized for a given production capacity that controls the pace at which the field is developed and the wells are drilled. At production start-up, only a portion of the proved reserves are developed in order to deliver sufficient production potential to meet capacity constraints and contractual obligations. Under these specific circumstances, the Group believes that it is justified to report as proved reserves the
level of reserves used in connection with the approved project, despite the fact that some of these PUDs may remain undeveloped for more than five years. In addition, TOTAL has demonstrated in recent years the Group’s ability to develop and bring into production similar large scale and complex projects, including the development of deep-offshore fields in Angola, Nigeria, the Republic of the Congo, HP/HT fields in the United Kingdom, heavy oil projects in Venezuela and LNG projects in Qatar, Yemen, Nigeria and Indonesia.
The tables provided below are presented by the following geographic areas: Europe, Africa, the Americas, Middle East and Asia (including CIS with specific figures shown for Russia).