In this series, our head of Rig Inspection Services Steven Lee shares tips on how operators and owners can get through rig inspections with flying colours – and which pitfalls to avoid! Mr Lee has more than a hundred rig inspections under his belt, from all parts of the world. Part 9 looks at power generation and supply systems.
The heart of a modern drilling rig, without doubt, is the power generation and distribution system. As rigs have increased in size and drilling capability, the power generation systems have had to scale accordingly.
Modern dynamic positioned drilling rigs can have upwards of 40 Megawatts of power, which could supply 40,000 homes. To assist with the delivery of these high power demands high voltage systems are utilised, with many of these now providing up to 11,000 Volts.
With regard to rig inspections in these areas, it is important that inspection teams see control of access to these restricted areas. If an inspection team asks to see the HV Switchgear areas they would expect to be challenged in being given unsupervised access.
Inside HV Switchgear areas, inspection teams will be expecting high standards of housekeeping and appropriate lifesaving equipment to be in place. They will be looking closely at any previously isolated equipment and are likely to cross reference this later against long-term isolation or permits to work.
An area of interest not only restricted to High Voltage switchboards – which thorough teams will look at – is whether electrical switchboards or distribution boards are installed with the correct insulated matting at both the front and rear of the cabinets. They will be looking for matting rating, which will be marked upon the rear of the matting, and for the certification.
Inspection teams will want to review main engine hours and next scheduled major overhauls, as no rig charterer would wish to be in a situation where they have just taken on a rig and it needs extensive reduced operational capacity due to major overhauls of engines. Engine overhaul periods can and should be closely monitored and managed to minimise impact upon the rig’s operations.
Finally, inspection teams are likely to be required, as part of a comprehensive rig acceptance program, to witness blackout recovery. The inspection teams will be watching closely not only at how the equipment performs in this situation but how the rig crew performs. Blackouts can be high-stress situations and require the rig’s technical team’s full attention. Experienced rig inspectors will understand the need to not interfere or get in the way during the blackout recovery phase.