Well-Work Intervention Solutions Best Practices, Experience and Lessons Learned from Challenging Deep and Sour North Kuwait Jurassic Gas Wells

Abstract NK Jurassic Gas Asset has strategic importance of Kuwait 2030 production set targets as the only non-associated gas producing fields. Being the Kuwait deepest gas producing asset mainly from deep, highly deviated and horizontal, high pressure and temperature, conventional and unconventional tight carbonate reservoirs, with critical percentages of H2S and CO2 in produced gas, the recovery from such complex heterogeneous reservoirs is extremely challenging hence requiring continuous applications upgrade of well-work solutions to assure flawless intervention operations. This paper will demonstrate the challenges and innovative well-work interventions solutions experience and lessons learned from the asset. The operations philosophy reviews and change of practices have followed various levels of intervention increased complexities throughout the field life to continue producing the Jurassic reservoirs safely and optimally. One key example was the switch from Oil Based Mud (OBM) completion fluids to brine based fluids as reservoir pressure depletion permits the adoption. Increased depletion of producing reservoirs has however drastically complicated the drilling of Marrat reservoir section and subsequent completion and well intervention operations. Wide range of well-work solutions, from short-landing the production liner to continue as open-hole to total depth associated with breaker pill spotting for oil-base-mud filter-cake effective removal till Managed-Pressure-Drilling (MPD) utilization to effectively manage pressure depletion till Under-balanced Coil-tubing drilling currently on first implementation phase, to widen the options for depleted reservoir sections drilling management. Evolution of thru-tubing plugs utilization for varying purposes other than stimulation mechanical diversion has enabled successfully attending critical workover jobs that otherwise deemed extremely dangerous and challenging. Easy mill-able plugs are regarded the true facilitator of OBM killing-free operations for many depleted wells and aided the safe handling of the challenging trapped pressure situations below fish in tubing string. Recent work string sizes enrichment for Jurassic operating rigs has been a major milestone for boosting the intervention capabilities for 4-1/2 in liners of monobore and multi-stage completed wells. Those well types had long intervention shortfall records since the design’s introduction in 2017, as Coil-tubing based limited wellbore access has been the solely available option for reservoir-face operations. The well cases through reviews have assisted scanning challenges throughout drilling/completion phase till rig-ess phase for deciding the fitting course of well-work solutions and the piloting plan then the wide field implementation of successful recipes. Problematic wells case approaches were provided with actions recommendation via the well-work solutions, fitting well challenges cases leading to successful interventions and achieving wells production targets. Such embracement of well-work solution packages, process, field experience, learnings and recommendations supported by case histories can be applied in other fields experiencing similar challenges.