Why has Iran opted to remove ONGC Videsh from the Farzad gas field bidding?

As of now, the reasons are not known but the National Iranian Oil Company or NIOC has announced ONGC Videsh or OVL will not get the Farzad-B gas field. Incidentally, it was OVL that had discovered these gas reserves in the Persian gulf. In an attempt to perhaps focus on localization of critical activities, Iran awarded the contract for developing the gas field to Iranian Petropars Group. The deal between NIOC and Petropars is worth $1.78 billion

The field was critical as it holds 23 trillion cubic feet of gas reserves. OVL and a consortium of Indian oil companies had been closely involved in the process. In fact, OVL had even offered to invest up to $11 billion to develop Farzad-B but Iran had not given India any firm commitment about the gas field development. India has already invested a huge $400 million in the block and it remains to be seen what it is able to recover.