Aban Offshore has received firm orders from ONGC for the deployment of three rigs - Aban III, Aban IV and Aban V - for a period of three years each following the completion of their existing contracts with ONGC.According to a release issued by Aban to the BSE today, the operating day rate for each contract is $1,56,600, and the total value of the contract is approximately Rs 2,000 crore.