Shares of companies engaged in crude oil exploration business fell sharply after crude oil prices crashed in international markets. The operator of world's largest crude-oil refining facility at Jamnagar and operator of KG-D6 basin in Krishna Godavari basin Reliance Industries slumped as much as 13.65%, its biggest single-day fall in at least 10-years, to hit an intra-day low of 1,096.65, data from BSE showed.