Recent industry analysis by Visiongain has estimated that the total expenditure in the global deepwater infrastructure market would reach $ 145bn in 2011 . In the Deepwater Horizon oil spill of 2010 , a large explosion occurred killing workers and spilling oil into the Gulf of Mexico while a BP oil rig was drilling in deep waters . Some of the earliest evidence of water wells are located in China . The Chinese discovered and made extensive use of deep drilled groundwater for drinking . The Chinese text '' The Book of Changes '' , originally a divination text of the Western Zhou dynasty ( 1046 -771 BC ) , contains an entry describing how the ancient Chinese maintained their wells and protected their sources of water . Archaeological evidence and old Chinese documents reveal that the prehistoric and ancient Chinese had the aptitude and skills for digging deep water wells for drinking water as early as 6000 to 7000 years ago . A well excavated at the Hemedu excavation site was believed to have been built during the Neolithic era . The well was cased by four rows of logs with a square frame attached to them at the top of the well . 60 additional tile wells southwest of Beijing are also believed to have been built around 600 BC for drinking and irrigation
Deepwater Horizon oil spill
Deepwater Horizon oil spill
Deepwater drilling