TAG Oil Ltd. is a development stage international oil and gas company, which engages in the production, development, and exploration of assets in New Zealand and Australia. It conducts oil exploration operations in Cardiff Deep gas discovery, Cheal discoveries, Kaheru Offshore JV and Sidewinder discovery in Taranaki basin, Waitangi Hill discovery, and Waipawa and Whangai source rock in unconventional oil. The company was founded by Alex P. Guidi on December 12, 1990 and is headquartered in Vancouver, Canada.