Mr Kloppers said the writedown on the Fayetteville assets was also a reflection of BHP's decision to change course and shift drilling from dry gas to liquid-rich fields.

BBC: BHP Billiton in $3.3bn writedown as gas prices plunge

The natural gas glut has caused natural gas drilling to be curtailed, making drilling equipment and workers available to shift to going after the oil.

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Secondly, layered on top of our core thesis, we see significant upside from a potential industry shift back toward natural gas drilling.

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