Geography 2152F/G Lecture Notes - Lecture 13: Blowout Preventer, Drilling Fluid, Wellhead
12 Apr 2019
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Document Summary
The depth of an oil well is considered to be deep water (1000 to 4999 feet). The waters of the gulf are difficult to drill because the seafloor falls of the gently sloping continental shelf into jumbled basin-and-range-like terrain, with deep canyons, ocean ridges, and active mud volcanoes 500 feet high. The commercial deposits lie deeply buried under layers of shifting salt that are prone to undersea earthquakes. Early reports from industry warned of the increasing risk of deep-water blowouts, the fallibility of blowout preventers, and the difficultly of stopping a deep-water spill after it started. Problems at the start with drill pipe got stuck in the borehole, as did the tool sent down to grind the stuck section, drillers had to back out and drill around the obstruction. Deepwater horizon was 6-weeks behind schedule and the delay was costing bp more than half a million dollars a day.
