The rocky road to oil riches

Colorado, America’s “Centennial State”, is home to four-and-a-half million people, lots of cattle, and potentially the world’s biggest reserves of oil.

The US Energy department thinks that the state is sitting on about a trillion barrels worth of oil, as much as the rest of the world’s conventional oil reserves added together.

Trouble is, it’s not quite ready to be extracted yet.

The state’s “black gold” is trapped thousands of feet underground in the kerogen-rich shale rock deposits of western Colorado.

If it was allowed to sit tight, a few more million years of heat and pressure would transform it into liquid pools ready to be drilled.

BBC