A Successful Story Of An Integrated Geologic And Reservoir Engineering Approach Of The Gandu Unit

Yaguaracuto, Alfredo (ConocoPhillips) | Bowser, Peter (ConocoPhillips) | Sands, Ken (ConocoPhillips) | Gamez, Amy (ConocoPhillips) | Keiser, Leslie (ConocoPhillips Co)


This paper presents the success story of an integrated approach to optimize the production performance of the Goldsmith Andector Unit (GANDU) in West Texas. All production is from the Clearfork formation, a typical carbonate reservoir characterized by large and discontinuous pay intervals with low reservoir energy and high residual oil saturation. This is a mature field which began re-development through a 20 acres infill drilling program in 2001, and has been under waterflood expansion since 2008. A multi-discipline team was commissioned to improve the production in the field. The team used an aggressive approach towards the development practices applied across the unit; from the reservoir engineering aspects, to the operational aspects. Reservoir characterization and numerical simulation work, in conjunction with classical methods, validated the 650 MMSTB of original oil in place in the reservoir; and validated the estimated Waterflood reserves. Also, operational guidelines were developed from the geological and engineering study. Through the operational aspect the team focused on the optimization of the base production, monitoring well performance, and detecting opportunities to optimize production through workovers, returning-to-production (RTP) jobs and recompletions. This paper details the systematic approach that was followed in order to achieve success including the geological characterization, the reservoir engineering approach, data acquisition, production monitoring, well automation, optimization of the field and development program for subsequent years. Details of the workflow implemented under the technical approach, best operational practices, lessons learned and path forward of the team are shown in the paper. As a result, the production of the field increased approximately 75% since 2001, with a total increase of 3000 BOEPD over a 2.5 year period.