Reports of a water wet reservoir in the primary target of the Twin Lions well have the shares of the participants plummeting with juniors Norwest Energy and Bounty being hit the hardest, with Bounty losing over 40% of its market capitalisation.

The only stock not heavily sold down was ROC Oil, who is being free-carried for a large percentage of the drilling costs by farmin partners.

The Irwin River Coal Measures formation was found to be water wet according to drilling reports released to the ASX this morning.

Bounty (5% equity) opened at 13c and had slid to 7.5c at press time (over 40%) with Norwest (10% equity) trading down at 8.2c after opening at 11.5c following heavy selling.

Australian Worldwide Exploration (20% equity) was a surprise casualty, shedding almost 15% to trade in the mid 80c range after trading at $1.00 at opening. With the significant Yolla discovery in the Bass Strait in the development phase, the market's reaction to the well surprised observers.

Other stocks hit were Voyager, down 14% to 20c; Arc Energy, down 9% to 91c; and Hardman, down 5% to 51c.

Norwest managing director Ivan Burgess said although there was still the High Cliff Sandstone target to be drilled lower in the well, he said he was not building anyone's expectations up, given the primary target had proven unsuccessful.