A Case Study on Downhole Measurement to Monitor Drilling Hazards in Integrated Ocean Drilling Program (IODP) Expedition 314

For integrated ocean drilling program (IODP) expedition 314, the deep sea drilling vessel Chikyu spent 56 days carrying out scientific drilling in the Kumano basin off the Kii peninsula. Drilling conditions were generally severe through the work of the expedition. In addition to Chikyu on-board measurement system, a state-of-the-art measurement while drilling (MWD) technology primarily intended for monitoring drilling condition such as borehole pore fluid pressure, rotary speed of the drill string. This study demonstrates the downhole measurement using MWD is effective for monitoring occurrence of drilling hazards in Nankai Trough seismogenic zone.