Location: Madura Strait, Indonesia
To overcome losses in the Wonocolo formation. One of the most difficult carbonate / limestone loss zones to plug off. Some of experienced drilling personel believe that Wonocolo is incurable. Nothing can stop if losses occur in this formation.
Starting from last casing at 1,769 5, despite of losses at >110 bph drilling from 1,790 ft, the 17½” hole was blind drilled to 3,189 ft (1,420 ft interval) using Seawater and Hivis sweeps. At 3,189 ft, (after passing through the Wonocolo formation) STOPLOSS pill of 777 bbls @ 45 ppb concentration was deployed in attempt to seal off the loss
After spotting STOPLOSS Static losses drastically reduced to 10 bph and then Zero. As static, the hole was then displaced to 9.8 KCL Lime Polymer mud and drilling operation was resumed without any problems.