Innovative Solution for Optimising Drilling Performance and Wellbore Stability: Western Desert, Egypt
by Philip McCurdy, Senergy
This case study from Egypt describes the results of a fully integrated, multi-stage wellbore stability and drilling optimisation project that significantly improved drilling efficiency and mitigated risk.
The first well of a three well exploration and appraisal program in the Western Desert in Egypt experienced significant problems including losses and wellbore instability issues. The well failed to meet objectives and poor hole conditions precluded wireline logging and inhibited formation evaluation.
The pre-drill planning phase for the second well included post-mortem and offset well reviews, highlighted key recommendations for improved performance, and raised awareness of geomechanical and drilling hazards and constraints. A drilling strategy was developed for the second well that optimised drilling procedures to minimise wellbore failure and to improve drilling efficiency, including: casing depth selection, drilling fluid design, optimised mud weights, BHA and bit selection, and tripping practices.
During the drilling phase on the second well, relevant time support to the drilling team was provided by dedicated geomechanics and drilling optimisation engineers to manage drilling performance, and to identify and mitigate geomechanical risks and hazards. This process enabled the second well to meet objectives with negligible drilling issues, and to reach TD in 56 days, 20 days ahead of AFE and 30 days ahead of the first well. Lessons learnt were captured for future wells.
The collaboration between drilling disciplines and the combination of best practice drilling performance and geomechanical workflows proved to be a key strategy for successful drilling.
Philip McCurdy, CV
Philip McCurdy is currently a Principal Geomechanical engineer with Senergy based in their Edinburgh office. Phil has 15 years experience in Geomechanics. Phil currently works predominantly on projects involving sand failure prediction and hole stability analysis.
His experience includes sanding management (sand control evaluation) and wellbore stability for fields in Asia, Russia, West Africa and the North Sea. Previously he was a senior geomechanics specialist in the applied geomechanics team within Helix RDS. Phil has also worked with IESL as a geomechanics consultant and a CT tool developer. He holds a BEng degree in engineering technology from Robert Gordon's University. Phil has 6 published SPE papers in the field of geomechanics and was chairman of the 3rd European sand management conference in Aberdeen, 2006. Phil was awarded an SPE award for Formation evaluation in 2010.
From the author:
“I am not sure who asked but if you could pass on the reference for the mud chemical question that would be most appreciated. The answer I was thinking of was silicates but I wasn’t sure till I checked.”
"Van Oort, Eric "On the physical and chemical stability of shales" Journal of Petroleum Science and Engineering 38 (2003) 213- 235"