Extreme Losses in Carbonate

Situation: Drilling 8 1/2 inch hole in Carbonate reservoir, at 6,877
ft MD (250 ft outside the last casing), using WBM 9.4 ppg. The
bottom falls out of the well, total losses, well kicks, close BOP,
keep well full with Seawater.

With the well closed in we can manage the pressures, we can bullhead
gas back into the formation. With the pumps off the annulus will
unload and displace to gas, it will not support a seawater column.

So far 13 LCM pills, of various make-up including Gunk squeezes,
have been pumped down without showing the slightets sign of plugging
off the the wellbore.
Over the last three days the well has absorbed in excess of 20,000
bbl of seawater and more than 1,000 bbl of LCM plugs, plus some mud.
Options that we can try SWELLCM (Turbochem), Flexplug (Hallibuton),
Form-A-Squeeze (MI/Alpine).

It looks like we have drilled either into a formation with extreme
porosity/permeability or a cave. Neither appears to be a candidate
for simple plugging off.

Is there anybody out there that has had simmilar problems and what
was done to resolve them.

Regards,
Huib

13 Answer(s)

---