Topic: Maximizing the Value of an Asset through the Integration of Log and Core data Speaker: Tim O’Sullivan (Petrophysical Consultant, Tullow Oil) When: 26 September 2013 Venue: PetroSA Audience: Invite All SPE members/nonmembers and students Abstract: In January 2004, the Mangala Field discovery well was drilled in the Barmer Basin of Rajasthan, in northwestern India. The petrophysical data acquired in this and subsequent wells allow a very precise estimation of field stock tank oil initially in place (STOIIP). This talk documents the techniques that allowed the estimate of STOIIP to be more precisely defined and to be revised upward by 12%, a substantial increase when dealing with a billion barrel field. The talk will demonstrate how very low water saturations are possible, and will verify the existence of Sw's that are typically less than 5%PV, and often near 1%PV, in a high-permeability and high-porosity reservoir containing little clay. The reservoir contains a medium gravity, highly paraffinic oil, and is intermediate to moderately oil-wet. The various laboratory datasets challenged some of the traditional assumptions concerning the use of Archie constants in such reservoirs for Sw calculations. The upward revision of STOIIP is significant, and can be principally attributed to the more accurate estimation of reservoir fluid saturations. This talk will clearly demonstrate the economic worth of extensive laboratory measurements and analyses on a high-volume, high-value reservoir such as Mangala. Biography: Tim O’Sullivan holds a B.Sc (Hons) degree in Geology from the University of Queensland, Australia. He has been working in the petroleum industry for more than 30 years, Australia , Asia, Middle East and Africa.. Disciplines include petro physics and development geology. Currently he is a petrophysicist to Tullow based in Capetown. He also delivers training courses for Next the Schlumberger Training company on core analysis and clastic and carbonate petrophysics. He is a member of SPWLA, SPE and AAPG and has published and presented with all three societies. He was an SPE distinguished lecturer in 2011 and presented to sections in Russia, Malaysia, Bangladesh, India, Turkey, Qatar, Sudan, Thailand and Uganda.