Shares in Jadestone Energy PLC surged 14% after news it is making headway in bringing its floating storage and production vessel back online.
Since the 10 August update, the company has made steady progress in addressing the issue.
Oil from the affected tank has been transferred to a shuttle tanker, allowing for inspections and cleaning.
The defects pose no safety, structural or environmental risks.
Jadestone is in discussions with Australia's National Offshore Petroleum Safety and Environmental Management Authority regarding the situation.
The company anticipates that the Montara production shutdown won't exceed 60 days. A detailed update is expected the week of 28 August.
At 8.35 am, the shares were changing hands for 25.37p, up 3.27p.