Ann: Trading Halt, page-31

To request a suspension from trading a company has to give valid reasons for the request to the ASX. For the ASX to grant a suspension they must agree that the reasons given are valid. In this instance with a well just completed and a flow test being conducted, the outcome of which (I think) will greatly affect the share price, the suspension is probably well justified.
There's also the possibility that they're negotiating with, buyers, banks, JV candidates etc the outcome of which also is price sensitive. Then again it could all fizzle, it's the nature of the beast.