Location: Offshore, East Kalimantan, Indonesia
Type of fluids: Mineral oil base, 13.0ppg
An offshore operator was making an open whole displacement of a water base system to a mineral oil system when sloughing coal and partial loss of returns occurred. Several attempts were made to combat the problem with various types of LC materials. None of these attempts were successful.
A 100 bbl sweep of 40ppb FRACSEAL(fine) was pumped around and full circulation was regained. Final displacement was made and drilling resumed. The hole was then swept on a regular basis to control sloughing and any seepagelosses. Prior to logging the well, a 50bbl pill of 12ppb FRACSEAL (fine) was left on bottom.
No losses were incurred while logging. Prior to running casing, a 50bbl sweep
of 12ppb FRACSEAL (fine) was pumped around. No losses were encountered while running casing and full returns were maintained during the primary cement job.