Core drilling is a method of drilling that involves using a special drill bit and drill to remove a cylindrical core of material. This technique is often used in construction and other industries to create holes.
[pdf] The Micro Oil Screw Air Compressor uses two rotors (screws) that rotate in opposite directions. As the screws turn, air is drawn in and compressed. The oil injected into the system lubricates and cools the compressor element while also sealing the gap between the screws.
[pdf] 
On 17 April 2002, a 44-year-old Norwegian worker on the rig was struck on the head and killed in an industrial accident. The accident resulted in Byford Dolphin losing an exploration contract with Statoil, which expressed concerns with the rig's operating procedures. .
Byford Dolphin was a , column-stabilised operated by , a subsidiary of . Byford Dolphin was registered in , and drilled seasonally for various. .
Byford Dolphin accident of 1983On Saturday, 5 November 1983, at 4:00 a.m., while drilling in the in the Norwegian sector of the , four divers were in a system on the rig's deck that was connected by a trunk. .
• Gjerde, Kristin Øye; Ryggvik, Helge (2009). [North Sea divers] (in Norwegian). Stavanger: Wigestrand Forlag.. .
Built as Deep Sea Driller, Byford Dolphin was the first-of-class in the highly successful H-3 series, designed by and completed at the shipyard in 1974.Byford Dolphin had an overall length of 108.2 metres (355. .
• • – Professional diving in support of the oil and gas industry• – Diving mode and decompression technique•
[pdf] 
