deepwater 'shallow string' cementing

17 January 2014 In shallow 'deepwater' flow environments due to lack of formation integrity, competence and where narrow margins between pore and fracture commonly exists.  

100-300psi above normal overpressure is all that is expected from potential flow zones. i.e. >8.66ppg and up to 9.0-9.3ppg depending on depth below mud line. (Ref for this IADC deepwater well control guidelines.)

With the section safely, drilled, and section tripped either conventionally or usual a dual gradient system e.g. annular cuttings loading, weighted sweeps, pump and dump, mud recovery etc.

Cementing often the greatest challenge to end each drilling phase.

What drives a prefernce for Foam (dominant in Gulf of Mexico) vs a light weight designer cement (dominant elsewhere world-wide) is then often debated in these deepwater 'flow prone' environments.

To allow a decision to be made on a current project,

What pro's and cons of these cementing methods, current knowledge, experience, best practise and ref to these systems and proceses used/applied by forum members is greatly appreciated.

regards,

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