Novel Grouting Composition Seals Challenging Loss Zone
Published: 02/22/2022
Novel Grouting Composition Seals Challenging Loss Zone
Published: 02/22/2022
Approximately 120 sacks of grout were mixed in 3,300 galUS of water using the rig hopper in a standard mix tank. After the grout was pumped and had time to settle, the contractor was able to drill through the strengthened formation without losses.
While attempting to drive 350 ft
of 54-in conductor casing, a drilling
contractor could only achieve 280 ft,
leaving a significant exposed rubble zone
that resulted in total lost returns.
The 22-in pilot hole under the Missouri River
was suspended by the environmental
inspector until a solution could be found.
The use of SMOOTH GROUT 30
30%-active-solids slurry grout was
recommended to seal the loss zone, and
an M-I SWACO field engineer oversaw
the mixing and the pumping of the bentonite grout
slurry. With the ground successfully
stabilized, the contractor was able to continue
drilling and achieve the target objective.
