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An operator drilling in Indonesia experienced severe losses in the 8 ½-in. interval. The losses began at 8,000-ft. about 2,000-ft. below the 9 5/8-in. casing shoe. The rate of losses in the first loss zone reached 120 barrels per hour (BPH) in a 9.6 lb/gal synthetic-based mud (SBM).
Three conventional 50 barrel 50 lb/bbl lost circulation pills were pumped and spotted at 8,062-ft., 8,230-ft., 8,352-ft., which reduced losses to 30-80 BPH. The losses quickly increased to 120 BPH at 8,514-ft. and three additional pills were pumped. These pills reduced losses, but logging-while-drilling (LWD) logs indicated a possible fracture at 9,295-ft. would accelerate the loss rate. Three additional pills were pumped (bringing the total to nine pills thus far of conventional LCMs (nutplug, calcium carbonate); however, losses were still occurring.
With the ongoing losses, the operator required a more robust solution to reduce lost circulation and selected LCP 2000 to plug the fractures and drill to section total depth (TD) past the fractured zones at 12,250-ft. Three LCP 2000 pills were pumped with background CaCO3 and the losses were reduced to 2 BPH.
LCP 2000 reduced the loss rate over 97%. With conventional LCM, 8,825 bbls of SBM were lost to the formation. With LCP 2000, a total of 185 bbls of SBM were lost. However, according to a post well analysis, the losses occurring while LCP 2000 was used were coming from the previous loss zones, higher up in the formation. The overall reduction in losses allowed the operator to drill through the troublesome intervals and reach planned well depth.