Debt-laden Tap Oil is to lose its chief executive and more than half its staff in a major overhaul forced by the plunge in prices that will see its major Asian shareholders significantly increase their control over the struggling junior.

The Perth-based explorer and producer will also raise $7.75 million in a rights issue to see it through the restructuring of its debt facility with BNP Paribas and Siam Commercial Bank, which is being shrunk due to the slump in prices.