Development of the telemetry system for the long-term borehole monitoring system

The international project supported by the Integrated Ocean Drilling Program (IODP) started in 2007 to drill the area off Kii Peninsula, JAPAN. This area is one of the most active earthquake zones. In the final stage of this project, Japan Agency for Marine-Earth Science and Technology (JAMSTEC) plans to install the Long-Term Borehole Monitoring Systems (LTBMS) in riser holes to take a direct look at activities of the plate boundary fault and subsidiary megasplays above it. As a part of the development of this LTBMS, JAMSTEC started developing an experimental prototype (EXP) of the telemetry system with IODP funding in February 2007. In United States Fiscal Year (USFY) 2007, JAMSTEC defined the engineering specifications for the telemetry system. LTBMS project team in Schlumberger K. K. (SKK) did a part of this work through outsourcing. JAMSTEC confirmed feasibilities of some technical features, such as high speed downhole data transmission, accurate time synchronization between land station and downhole systems, and so on. This paper reports the engineering specifications and relating investigations.