Horizon chief Brent Emmet said they suspended the well in 1998 when they encountered salt in the well and the mud system being used at the time was unsuitable.
Emmet said they found minor gas shows but the real target was the very prominent structure they had observed, but had not been able to drill.
The well will take about 26 days and is expected to spud in the last week of this month. Horizon has put a mean reserves potential of 600 billion cubic feet of gas on the structure. Horizon has 14.29% interest with an option to take up to 21.79%.