There has been another hit to the reputation of the oil and gas industry, with confirmation of a second gas leak in the Timor Sea.

The Northern Territory Government says a small amount of non-harmful gas has escaped from the Puffin oil field, which is operated by Chinese oil and gas company, Sinopec.

The leak was discovered early last month as part of a routine inspection.

The Puffin field lies about 50 kilometres north west of the West Atlas oil rig, where oil has been leaking from a well for nearly 10 weeks.

The Territory Government says the company will take measures to cap the gas leak. The amount of gas that has escaped from the well is not known.

Meanwhile the company operating the West Atlas oil rig has conceded it could take several more attempts to plug the well.

It is estimated that more than 400 barrels of oil a day has been spewing into the ocean since an underground pipe ruptured almost ten weeks ago.

Rig owner, PTTEP Australasia, says oil has reached Indonesian waters but has not reached the coast.

The company's director Jose Martins says it is a difficult operation.

"We had planned that it would have been achieved by now, it hasn't worked that way, and we would obviously plan now to have another pass this weekend," he said.

"It may require another attempt after that and if that fails another one after that, and at that point we should be at very high confidence."