OPaL, promoted by ONGC and co-promoted by Gujarat State Petroleum Corp (GSPC) and gas company GAIL (India) Ltd, operates a cracker which has a capacity of 1.1 million tonnes of ethylene a year.
"We are supplying all of the naphtha to OPaL...we will export if our laycans do not match with that of OPaL's," said a company source, adding that OPal is working out its strategy to source some quantity from the market as well.
A cracker of this size typically consumes more than 3 million tonnes of naphtha a year, based on Reuters calculation, but OPaL cracker is able to run on gas and naphtha.
"OPal did not run full until recently," said a second source, explaining why ONGC only stopped halting exports this year.
ONGC is the key supplier of feedstock to OPaL, with the raw material coming from Hazira, Uran and Dahej in western India.
ONGC Hazira was exporting one to two 34,500-tonne cargoes a month in 2016 but this stopped this year, based on Reuters data.
ONGC was also exporting an average 35,000 tonnes of naphtha a month from Mumbai in 2016. It last sold a cargo for January 2017 loading.