Reply #5: Have you seen this powerpoint? [View All]

From Halliburton’s presentation (large pdf), page 10, last November (my bold):

Challenges

• Shallow water flow may occur during or after cement job
• Under water blow out has happened
• Gas flow may occur after a cement job in deepwater environments that contain major hydrate zones.
• Destabilization of hydrates after the cement job is confirmed by downhole cameras.
• The gas flow could slow down in hours to days if the de- stabilization is not severe.
• However, the consequences could be more severe in worse cases.

Page 13 lists the design objectives but then concedes they can’t all be met at once:

Deepwater Well Objectives
• Cement slurry should be placed in the entire annulus with no losses
• Temperature increase during slurry hydration should not destabilize hydrates
• There should be no influx of shallow water or gas into the annulus
• The cement slurry should develop strength in the shortest time after placement
Conditions in deepwater wells are not
conducive to achieving all of these
objectives simultaneously

http://seminal.firedoglake.com/diary/44349