Publications

Exploration in deep water poses a challenging environment for drilling because of very narrow safe mud weight window with little margin of error. Therefore, thorough planning and efficient and safe drilling are essential for a successful drilling campaign. This paper is a summary of a recent successful drilling campaign in the East Java sea. Kangean Energy Indonesia (KEI), as part of their exploration strategy, drilled an exploration well with a water depth of 3,057 ftMD located in the South Saubi Prospect in Block E, Kangean PSC, East Java Sea, Indonesia. In between 1990 and 2000, there were five exploration wells drilled near South Saubi Prospect and based on drilling experiences, there have been numerous drilling problems that have occurred such as kick, pack-off, BHA stuck, forced side-track and loss circulation. These five wells are vertical well and the primary target was Prupuh/Kujung/Ngimbang reservoirs. Real-time geomechanics services were employed to provide an estimate not only for safe mud weight windows that were bounded by pore pressure and fracture gradient but safe and stable mud weight windows whereby breakout/collapse and breakdown mud weights were estimated in addition to pore pressure and fracture gradient in order to avoid stuck, pack-off, tight hole, etc. Geomechanics engineers updated the pre-drill geomechanical model using logging-while drilling data: gamma-ray, resistivity, sonic, density and seismic that were streamed in real-time. Using these logs, pore pressure, breakout/collapse, fracture gradient and breakdown and mud weights were generated in real-time. These estimated mud weight windows were analyzed and interpreted in conjunction with drilling mechanics, mud logs, cutting/cavings analysis, ECD and ESD for safe and stable mud weight recommendation. This window was further calibrated while drilling with LWD formation pressure measurement and leak-off test. Real-time updates on safe and stable mud weight enabled several critical decisions to be made such as optimized casing depths and mud weight management. The Southern Basin Exploration well was eventually drilled safely with minor and manageable drilling problems.