JAKARTA - Five wells in Indonesia's Mahakam block operated by Total will be cemented shut as a result of a gas leak from a shallow reservoir, the company said on Monday, although the impact of the closure is expected to remain minimal.
The wells in the Tunu field represent around 3 percent of gas production from the Mahakam delta in East Kalimantan, Indonesia's biggest source of natural gas with output currently at 1.74 billion standard cubic feet a day.
Five wells had to be shut temporarily to stop the leak from a shallow reservoir under a development well from spreading, Total Indonesie spokesman Arividya Noviyanto told Reuters, without indicating how long the closure would last.
"We did the cementing operation yesterday. One of the wells is already closed," Noviyanto said, referring to the development well, adding another four production wells would also be closed soon. Total E&P Indonesie is a unit of France's Total.
The combined impact from the closures on production was currently around 50 million standard cubic feet a day (mmscfd) he said, adding they aimed to slow this to around 20 mmscfd. "It is in a stable condition now. Later we will remove the rig," Noviyanto said, referring to the Raissa drilling rig owned by PT Apexindo Pratama Duta.
The Tunu wells are among hundreds in the Mahakam block, Noviyanto said, which is producing in excess of its target for this year of 1.577 billion standard cubic feet a day. The Tunu field produces around 800 mmscfd.
Domestic media reported that a team of experts had been flown in from the US and France to stop the leak. "We are still reviewing the impact on production next year."
Indonesia's oil and gas regulator said it was also calculating the impact of the closures on production. "They are trying to recover the situation," SKKMigas secretary Gde Pradnyana told Reuters, adding Total was in discussions with the government over how to dispose of mud from the well's drill cuttings.
A source with direct knowledge of the matter said it could take at least until the end of December to stop the leak, which threatened to cause a crater if not resolved.
An earlier release from the company said the leak had not shown any indications of liquids, and that all employees working in the area had been evacuated safely.
"TOTAL is currently deploying all necessary resources to mitigate this incident which has been reported to the relevant authorities," the company said.
The Mahakam block is jointly operated by Total and Japan's Inpex Corp, and its gas is exported to Japan, South Korea and Taiwan.