Location: Offshore West Java, Indonesia
One of notorious loss areas in Indonesia, a troublesome carbonate/limestone section. Common problems are Severe losses and Hole Pack offs. In this interval, drill bits can easily encounter natural fractures and cavernous formations.
Starting from last casing at 380 ft the 17½” hole was drilled using Seawater and Hivis sweeps. Drilling at 935 ft had sudden Dynamic loss at 423 BPH and then Total losses. Static losses observed was at 120 BPH. STOPLOSS pill was deployed by pumping in sequence 20 bbls lead Hi-Vis spacer, 50 bbls @45 ppb STOPLOSS pill and 20 bbls tail Hi-Vis spacer.
After spotting STOPLOSS Static losses reduced to 10 BPH and then nil. Washed down to 935 ft and then hole was displaced to 9.0 KCL Polymer Mud. Drilling was resumed to target depth without any problems.