Re-Engineering and Upgrade of a Semiautomated 3,000-hp Drilling Rig
Authors: Wilson Adam 
Published: February 2015

This article, written by Special Publications Editor Adam Wilson, contains highlights of paper SPE 164019, ’Re-Engineering and Upgrade of Semiautomated 3,000-hp Drilling Rig for KOC HP/HT Exploration Program in Frontier Areas—Case History of UPDC Rig 776,’ by A. Al-Saleh, SPE, M.D. Al-Khaldy, SPE, A.A. Shehab, SPE, F.A. Al-Naqa, SPE, and S. Baijal, Kuwait Oil Company; M.F. Karam and S. Schmidt, United Precision Drilling; and D.C. McKinnell, SPE, Total Kuwait, prepared for the 2013 SPE Middle East Unconventional Gas Conference and Exhibition, Muscat, Oman, 28-30 January. The paper has not been peer reviewed.

In 2011, the Kuwait Oil Company (KOC) considered enhancement of equipment specifications for deep drilling rigs to integrate state-of-the- art technologies. UPDC Rig 776 was the first to be upgraded, and this work was handled as an integrated project by the rig contractor working closely with the field operator. With regard to the rig design, major changes were made to enhance safety, capacity, and automation of the drilling functions.

Purpose of the Upgrade

The drilling of future deep high-pressure/ high-temperature wells in Kuwait will become more challenging. New frontier areas with increased depth and formation difficulty are being targeted. To ensure that the deep drilling rigs will be able to meet these future challenges and to improve safety and operational performance, KOC has enhanced the deep-drilling- equipment specifications for their new contracts.

For Rig 776, this required a major upgrade or replacement of all core rig components.

The subbase height had to be increased to be able to incorporate a full 15,000-psi blowout-preventer (BOP) -stack rig-up.

The topdrive system had to be upgraded to cope with higher mud-flow rates and pressures, and a control system for the driller was to be installed.

Mud pumps were replaced with new 2,200-hp pumps, producing up to 7,500 psi.

The rig power system was upgraded with five new 1,855-bhp (maximum) engines and a new selective catalytic reduction (SCR) system.

An upgrade of the drawworks included an integrated disk brake system and installation of a semiautomated control system for the driller.

The iron roughneck was enhanced.

The mud system was upgraded.

These improvements were aimed at enhancing safety, capacity, and automation of the drilling functions. In addition to these major changes, the rig camp was completely refurbished and the camp power generation was upgraded to silent packages.

Rig-Upgrade Works

Once Rig 776 finished drilling the last well before the upgrade, the rig was prepared for the yard work. As the rig commenced to rig down for the move to the project yard, all equipment had to be cleaned properly. The mud tanks had to undergo sand blasting before inspections could be conducted. The cleaned equipment was then moved to the project yard. The rig offices were set up in the project yard to provide extra office space.

Subbase and Mast. The subbase height had to be increased by 10 ft. This was accomplished by changing out all existing subbase legs. With the new subbase height, all stairs, escape slides, piping and hoses, and the personnel elevator to the rig floor had to be modified or replaced and the V-door ramp had to be extended.

In addition to increasing the height of the subbase, the entire subbase and mast underwent inspection and recertification. This required sand blasting of all components, inspection, and repainting. Any defects found had to be repaired, with parts replaced as needed.

Once work on the subbase and mast was completed, a new 120-ton BOP hoist system had to be installed. The spill containment (drip pan) was replaced under the rig-floor area.

On the rig floor, the existing ST-80 iron roughneck had to be replaced with a large-capacity IR10-100 roughneck. A new 20,000-lbm air tugger also was installed.