Backstory
When tai-pan Ian Dunross learned in Noble House that the North Sea may soon be wide open for oil exploration, he sent Andrew Gavallan to Scotland to quietly buy up real estate in Aberdeen so they would be positioned to take advantage of this trend. The North Sea oil rigs, once built, are serviced by helicopter, which leads to Gavallan being involved in the helicopter and oil services industries. These become main business ventures of Struan's in Iran during the 1970s, as depicted in Whirlwind.
Read more about this topic: Whirlwind (novel)