The rigs were procured by ONGC in the 1970's and 1980's. Of these, nine were supplied by BHEL, while the rest were supplied by American companies. This is the fourth major order awarded to BHEL by ONGC under their programme of refurbishment and upgradation of ageing rigs with state-of-the-art technology. For the contract, the mechanical jobs will be done by BHEL's Hyderabad plant, while the electrical jobs will be undertaken by the company's Bhopal plant.
The scope of work involves repair and replacement of structural members of mast and substructure, overhauling of rotating and hoisting equipment, revamping electrical systems and site erection, and commissioning of these equipment.