While the foundations were being dug, a steel-and-timber-framed shell of the house was built off-site.

WSJ: Striking Gold in the Backyard

In a meeting with investors in November, Shell CEO Peter Voser ticked off how the firm is investing today to capitalize on long-term global demand.

FORBES: Shell's 5% Dividend Yield (Part 2): Will Huge Capital Spending Pay Off?

They point to the Sakhalin-2 project off Russia's Far East coast, where Gazprom gained majority control from Royal Dutch Shell last year, after Russian authorities refused to give Shell environmental clearance for the scheme.

BBC: NEWS | Business | Gazprom talk lifts Centrica stock

For foreign majors like Royal Dutch Shell PLC and BP PLC, their former heartlands in the Gulf sands are now largely off-limits.

WSJ: Big Oil Companies Are Shifting Their Focus Back to the West

"How the sound reflects off this reflecting surface with this composite object on it - which is pretty big and has a cloaking shell on it - really reflects... just like a flat surface does, " Dr Cummer said.

BBC: Acoustic 'cloaking device' shields objects from sound