As a result of the vessel blocking other tankers from entering, APLNG, operated by ConocoPhillips (COP.N), has so far deferred two LNG cargoes and Origin warned "it expected that more LNG cargoes will be deferred".
APLNG, which has a capacity of 9 million metric tons per annum (mtpa) of LNG, can only take one vessel at a time and on average loads one tanker every three days at Curtis Island off Australia's east coast.
Its two main customers are China's Sinopec (600028.SS) and Japan's Kansai Electric (9503.T).
Vessel tracking data showed the disabled tanker is the Cesi Qingdao, which was due to go to Wenzhou in China. Origin and APLNG spokespeople were not immediately available to comment on who owns the cargo.
Origin, the country's biggest energy retailer, supplies gas to APLNG, which is co-owned by ConocoPhillips, Origin and Sinopec.
ConocoPhillips is working with all parties concerned, including the relevant maritime regulator and port authority, to resolve the situation, Origin said.
The total numbers of cargo deliveries which could be deferred will depend on when the situation resolves, it said.
"In addition, Origin is taking steps to bank its non-operated portfolio production and execute additional domestic gas sales," the company said.
Shares in Origin, which is subject to a $10.6 billion takeover offer from a consortium led by Canada's Brookfield, were down 0.6% at A$8.48 as of 0108 GMT.
