Offshore drilling is defined as drilling below water surface, mainly in seas and oceans, with rigs consisting of either floating or fixed platforms on the bed of the ocean to support drilling. There are many different types of facilities from which offshore drilling operations take place. These include platforms, jack-ups, drill ships and semi-submersibles.
Offshore wells are drilled in much the same way as their onshore counterparts with several allowances for the offshore environment. A conduit made from lengths of steel pipe permits drilling fluids to move between the rig at the water's surface and the sea floor. This conduit is called a "riser."
The well is drilled using a length of steel pipes and other tools that, connected, comprise a "drill string."
The drill string is lowered through the riser to the sea floor, passing through a system of safety valves called a "blowout preventer" (BOP, pronounced "B.O.P."). This stack of multiple safety valves is designed to contain any natural pressures that the drillers might encounter beneath the Earth's surface. Its purpose is to prevent a possible "blowout", an uncontrolled eruption of oil, gas or wellbore fluids due to excessive natural pressure.
Offshore drilling is more challenging than land-based installations due to remote and harsher environment. The industry is constantly improving technology and practices to optimize well placement, reduce drilling costs and increase production. Cost concerns remain a real issue. Rig day rates make running a rig expensive, which means that the speed of rigging down, moving and rigging up is crucial to guarantee project success. Drilling equipment has to be reliable and easy to handle on the rig.
All these specifications requires products capable of drilling:
on platforms, jack-ups, drill ships, and semisubmersibles
in water depths exceeding 12 000 ft (3700m)
in extended reach, deviated, and deep wells
despite unexpected pressure variations and low pressures in reservoir
while withstanding corrosion, storms, high seas, and strong currents
Products & Solutions
COMMAND-SMFI offers custom drill strings to meet offshore challenges: