BP's £900m punt on difficult fields

BP is taking a big bet on lifting gas from difficult fields in the US by spending nearly £900 million on assets in Oklahoma.

Under pressure in Russia, where it increasingly seems as if it may be forced to partially withdraw, BP is looking to the West again and is paying $1.75 billion for so-called "unconventional" gasfields from Chesapeake Energy.

BP is acquiring interests in reservoirs deemed too difficult or expensive to lift in the past.

The Chesapeake deal gets the oil giant access to shale gas found in dense rock which can be accessed only by state-of-the-art drilling techniques.

The decision is seen by analysts as a stark change in direction for BP.

It follows similar pushes into unconventionals by Shell, which earlier this week spent £3 billion buying Duvernay Oil, furthering its production and search for assets in the expensive-to-refine Canadian oilsands fields.