Drilling in North Kuwait presents significant challenges due to the hard rock in the overburden that needs to be drilled in large hole sizes en route to the targeted deep Jurassic reservoirs. A project was taken up in order to improve the drilling performance (especially Rate of Penetration, ROP) thought the hard layers located in three upper sections of the wells (28,″ 22″ and 16″) by implementing the "Drilling Efficiency Optimization" (DEO) methodology. DEO is an overall process to improve drilling performance by increasing ROP and bit footage through the utilization of efficient drilling practices throughout the planning, execution, and post-drilling phases.

This paper describes the strategies, practices and "Driller Roadmaps" that were developed to improve ROP and drilled footage on the three sections of interest. The drilling parameters and results from three trials implementing the proposed improvements are also included. Field data demonstrates that by optimizing BHA (Bottom-Hole Assembly) design, bit hydraulics and drilling parameters through DEO process, the ROP was improved by over 70% on average in the three hole sections in which the trials were conducted. Also, due to the ROP improvement and longer bit run durations, a total of 17 rig days was saved. One bit established a new record for the longest 22″ TCI bit run ever achieved in North Kuwait (total footage: 2883 ft). Furthermore, the entire 16″ section was drilled using only two PDC bits, for the first time ever.

The paper also provides recommendations on the next steps in DEO implementation to further improve drilling performance in North Kuwait wells. The insights provided in this paper will assist KOC in their endeavours to improve the overall drilling performance in their operations, especially drilling hard rock. The lessons learned have led to best practices being developed for the North Kuwait wells and serve as a valuable benchmark for projects located in the vicinity.

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