Application of KISOS for the Monitoring Environmental Risks Assessment in Deep-water Gas Hydrate Test Production in the Ulleung Basin, East Sea of Korea

Abstract:

Korea Institute of Geoscience and Mineral Resources (KIGAM) has developed the KIGAM Seafloor Observation System (KISOS) for the baseline studies in the monitoring gas hydrate test production in the deep-water (>2,000m) Ulleung Basin of the East Sea of Korea. The KISOS consists of an acoustic positioning system (USBL), altimeter, still camera, video camera, water sampler, measuring devices (dissolved methane, dissolved oxygen, turbidity, chlorophyll, and currents) mounted on the unmanned ROV, and a seafloor sediment collecting device.

The ultimate goals of the seafloor monitoring are to assess environmental risks (gas leakage and production water/drilling discharge, and so on) which may occur during and after the gas hydrate test production drilling. The KISOS was applied to solely conduct baseline studies during the last three years. We will conduct the KIGAM seafloor monitoring system (KIMOS) of the Korean gas hydrate program in the future. The large scale of environmental monitoring program includes the environmental impact assessments such as seafloor disturbance and subsidence, detection of methane gas leakage around well and cold seep, methane bubbles and dissolved methane, change of marine environments, chemical factor variation of water column and seabed, diffusion of drilling mud and production water, and biological factors of biodiversity and marine habitats before and after production drilling test well and nearby areas.

Topics that will cover include:1) configuration of KISOS and general layout/operational design of KIMOS, 2) numerical simulation of gas and materials transport using SIMAP/CHEMMAP + MUDMAP softwares, 3) sensitivity analysis such as gas leakage modeling, operational produced water discharge, and 4) modeling of drilling discharge with cuttings and mud.

Key words: gas hydrate, environmental monitoring, KISOS, KIMOS, Ulleung Basin