Tullow Oil plc's Calao-1X exploration well, in the CI-103 licence off the Ivory Coast, encountered thin condensate/gas-bearing reservoirs in an Upper Cretaceous deepwater channel system, the company announced on 30 May 2013. Following completion of logging operations, Tullow plans to plug and abandon the well.
The well is the second deepwater exploration well drilled in the CI-103 licence and targeted an Upper Cretaceous channel system northwest of the Paon-1X oil discovery, which was drilled in 2012. Good-quality reservoir sandstones were found in this objective but they were water-bearing at this location. Approximately 5m of condensate/gas bearing sandstones were found in a deeper objective.
The well was then sidetracked, targeting a better developed reservoir unit down-dip. Good-quality water bearing sandstones were intersected at that level in the sidetrack. Pressure data indicates that this zone may be in communication with the condensate encountered in the original Calao-1X well.
Tullow's Exploration Director Angus McCoss, said: "While this is not the result we were aiming for, both the condensate and the reservoirs that we encountered have added substantially to our knowledge in this frontier area. The appraisal of the light oil discovered down-dip in Paon-1X in 2012 will continue later this year with the drilling of the Paon-2A well. Having sold some of our equity for carries in the CI-103 licence - a decision that was taken prior to the drilling of the Calao-1X well - our stake in both the Calao-1X and Paon-2A wells has been consequently reduced."
Seadrill's West Leo dynamically-positioned semisubmersible drilled Calao-1X to a final depth of 4,570m in water depths of 1,906m. The Sidetrack was then drilled to a final depth of 4600m below sea level.
Tullow operates the CI-103 licence with 30% carried interest. Its partners include Anadarko Petroleum (55%) and the Societé Nationale d’Opérations Pétrolières de Côte D’Ivoire (Petroci) (5% plus a 10% carried interest).