KOC have been drilling deep HP/HT wells for over thirty years during which time the well prospects have become more challenging, aiming for new frontier areas with increased depth and formation difficulty. The rig designs employed have therefore been developed over the years with new technologies being incorporated to meet these challenges, and to improve safety and operational performance.

In 2011 KOC looked into the enhancement of the equipment specifications for deep drilling rigs to integrate ‘State-of-the-Art’ technologies in the new contract terms. UPDC-776 was the first of the existing fleet rigs to be upgraded and this work was handled as an integrated project by the rig contractor working in close cooperation with the field operator.

With regard to the rig design, major changes were made to enhance safety, capacity and automation of the drilling functions. These modifications included; re-design of sub-structure to incorporate full 15K BOP stack rig-up, upgrade of TDS, 2200HP mud pumps and associated 7500 psi discharge pipework, new power train and SCR system, upgraded drawworks with semi-automated control system, iron roughneck and power slips, increased capacity mud system with latest design solids control equipment. The actual rig modifications were carried out within the scheduled time and performance has been improved with less downtime than comparative new build start-ups.

This paper will describe the ‘Upgrading Project’ including the re-engineering and design, rig modifications and construction phase, commissioning / break-in operations on the first well. The case study will make particular reference to the planning, logistics, and teamwork employed during this process and conclude with lessons learnt plus recommendations for future rig modification projects.

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