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] A drilling riser is a conduit that provides a temporary extension of a subsea oil well to a surface drilling facility. Drilling risers are categorised into two types: marine drilling risers used with subsea blowout preventer (BOP) and generally used by floating drilling vessels; and tie-back drilling risers used with a surface BOP and generally deployed from fixed platforms or very stable floating platfor. Marine drilling riserA marine drilling riser has a large diameter, low pressure main tube with external auxiliary lines that include high pressure choke and kill lines for circulating fluids to the subsea (BOP), and usually po. .
A tie-back riser can be either a single large-diameter high pressure pipe, or a set of concentric pipes extending the casing strings in the well up to a surface BOP.
[pdf] Mars field was discovered in 1989 at around 130 miles south of New Orleans. The field, located at 3,000ft water deep, started production in 1996. Mars B was discovered after Shell geologists located untappe.
[pdf] 
