Location: Onshore, North Sumatra, Indonesia
Type of fluids: Diesel based Invermul, 9.7 ppg
An operator was drilling a well below 9.000’ when a depleted zone was penetrated and dynamic mud losses of 180bph were encountered.
The drill string was picked up and a 30bbl pill of 15 ppb FRACSEAL (fine) and 15ppb FRACSEAL (coarse) was pumped to the bottom. Dynamic mud losses were reduced to 20bph. A second similar 30bbl pill FRACSEAL (fine) and FRACSEAL (coarse) was pumped to the bottom and losses were reduced to 4bph. Drilling was resumed with a reduced pump rate while adding 12ppb of FRACSEAL (fine) to the mud system.
Dynamic mud losses were reduced to less than 1bph. Before T.D. was reached, full returns were obtained. Prior to both logging and running casing operations, the hole was swept with a 40bbl pill of 10ppb FRACSEAL (fine). There were no losses during logging and full returns were maintained throughout the primary cementing.