Oil and Natural Gas Corp, which had last year firmed up an investment of Rs 34,012 crore (USD 5.076.37 billion) in bringing to production 10 oil and gas discoveries in its Bay of Bengal block KG-DWN-98/2 (KG-D5), plans to invest another Rs 21,528.10 crore (USD 3.2 billion) in developing the ultra-deepsea UD-1 find.