CHALLENGE
AGR was contracted by two small independent Operators to design, manage and construct their exploration drilling venture in the Southern Atlantic basins.
AGR had to overcome geological uncertainties and provide flexible but robust well designs based primarily upon 3D seismic interpretation and pore pressure and fracture gradient studies.
APPROACH
AGR used conservative pore pressure scenarios, ensuring robust design if worst-case pressure developed and flexibility if low-case encountered.
Real-time rock strength analysis was used effectively alongside pore pressure analysis to monitor setting depths and maximum burst pressures expected. Intermediate checkshot data interpretation results were analysed by AGR to ensure casing setting depths were optimised throughout.
AGR Well Management team re-designed the final well following analysis of analogous formation in previous well-resulted in deepening of 20” and 13-3/8” setting depths and ultimately omitting a string of casing, with TD reached in 12-1/4”.
24,000 MT of equipment was planned and mobilised by AGR's
Integrated Logistics team - no time was spent waiting on AGR planned/mobilised equipment.
RESULT
- Deepest well drilled in the UK registered waters, designed with only limited offset data. Reached all targets and proved hydrocarbon source
- Final well saved ~£12m due to re-design omitting 9-5/8” casing. Excluding rig downtime, well came in under AFE time and cost and proved hydrocarbon source
- 3rd well completed 1 day over AFE despite running additional contingency casing string
