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TITLE

Research on the Carbon Dioxide Monitoring by the Time-lapse 3D Seismic Survey
(Joint Program to Promote Technological Development with the Private Sectors)

AUTHOR

RITE - TOKYO SHINAGAWA LABORATORY in JAPAN PETROLEUM EXPLORATION CO., LTD.
RITE - CHIBA MIHAMA LABORATORY in JAPAN PETROLEUM EXPLORATION CO., LTD.

SOURCE
ABSTRACT Geologic sequestration by carbon dioxide injection is the promising method to mitigate the global climate change due to excess carbon dioxide emission to the atmosphere. To verify the long-term subsurface safe storage of carbon dioxide in the aquifer, and others, it requires monitoring during and after the injection. Time-lapse 3D or 4D seismic monitoring is the most effective to spatially and efficiently detect the fluid movement and the change of pore pressure in the subsurface, which has been evidenced by case studies in the hydrocarbon industry.

In the Iwanohara field, Nagaoka, onshore Japan, approximately 10,000 tons of carbon dioxide was injected in the aquifer zone during the period of July 2003 to January 2005 by RITE/METI. In order to monitor injected carbon dioxide, 4D seismic survey was conducted in 2003 as baseline survey and in 2005 as a monitor survey, which was the first 4D seismic monitoring for the carbon dioxide injection to the onshore saline aquifer in the world. 4D anomaly zone caused by possible carbon dioxide saturation effects was identified and mapped in the aquifer zone by several methods. Non-linear clustering method was to reduce data redundancy and remnant non-repeatable noises inherent to the onshore 4D seismic data and it turned out to have improved the conventional visual inspection of simple math difference of 3D seismic volume. 3D data were evaluated by well synthetics and impedance inversion to estimate physical parameters and were implemented to both clustering analysis and estimates of physical parameter distribution. Identified 4D anomaly has a spatial correlation with the higher permeability distribution map on the injection zone estimated by baseline 3D volume. To estimate carbon dioxide saturations from 4D anomaly data, rock properties of the target aquifer had to be evaluated and rock physics approach was effective.