03.08.2009

Many deepwater fields are developed as subsea completions with production either tied back to a platform in shallow water or transmitted to a floating production system.

In many cases the processing facility is remotely located from the producing wells. Therefore flow assurance in the gas gathering system is critical of all subsea deepwater developments. Sea bottom temperature is cold and cooling of wellstreams during transmission can lead to formation of problematic hydrates and other solids such as waxes and asphaltenes which can clog flowlines and other subsea equipment.

The flow of produced oil and gas can be decreased or stopped by hydrate and wax formations inside steel pipe caused by its poor insulation properties against cold. This effect can be magnified by the coil-like internal structure of steel flexible pipe

Check valves that permit fluid to pass downward, but not upward through the casing. A float collar is a special coupling device inserted one or two joints above the bottom of the casing string. A float shoe is positioned at the end of the casing

Any radioactive or stable nuclide resulting from fission, including both primary fission fragments and their radioactive decay products

The splitting of a heavy nucleus into two, accompanied by the release of a relatively large amount of energy and usually one or more neutrons. It may be spontaneous but usually is due to a nucleus absorbing a neutron and thus becoming unstable

The energy made available to the consumer before its final conversation, namely before final utilisation.