A drilling riser is a conduit that provides a temporary extension of a to a surface drilling facility. Drilling risers are categorised into two types: marine drilling risers used with subsea (BOP) and generally used by floating drilling vessels; and tie-back drilling risers used with a surface BOP and generally deployed from or very stable floating platfor.
[pdf] Offshore drilling is a mechanical process where a wellbore is drilled below the seabed. It is typically carried out in order to explore for and subsequently extract petroleum that lies in rock formations beneath the seabed. Most commonly, the term is used to describe drilling activities on the continental shelf, though the term can also be applied to drilling in lakes, inshore waters and inland seas. Of. HistoryAround 1891, the first submerged oil wells were drilled from platforms built on piles in the fresh waters of the in . The wells were developed by small local companies such as Bryson, Riley Oil, G. .
Offshore drilling is usually done from platforms generically known as mobile offshore drilling units (MODU), which can be of one of several formats, depending on the water depth: •. .
Notable offshore fields include: • the • the (offshore , , , and )• (in the and , part of the Ventura Basin).
[pdf] 
Deepwater Horizon was an ultra-deepwater, dynamically positioned, semi-submersible offshore drilling rig owned by Transocean and operated by the BP company. On 20 April 2010, while drilling in the Gulf of Mexico at the Macondo Prospect, a blowout caused an explosion on the rig that killed 11 crewmen and ignited a fireball visible from 40 miles (64 km) away. The fire was inextinguisha. DesignDeepwater Horizon was a fifth-generation, RBS-8D design (i.e. model type), deepwater, ,. .
Deepwater Horizon was built for R&B Falcon (which later became part of ) by in , South Korea. Construction started in December 1998, the was laid on 21 March 200. .
At 7:45 p.m. on 20 April 2010, during the final phases of drilling the exploratory well off the gulf of Mexico, a geyser of seawater erupted from the onto the rig, shooting 70 metres (230 ft) into the air. This wa. .
Transocean received an early partial insurance settlement for total loss of the Deepwater Horizon of US$401 million about 5 May 2010. noted that the insurance recovery was likely to be more than t.
[pdf] 
