Improvement of the Tracer Test Method for the 10cm Scale Single Fracture

Sato, Hisashi*; Takebe, Atsuji

In case of measuring tracer concentration using an electrical conductivity meter, tracer residence time will be overestimated due to the relative larger volume at electrical conductivity meter and tubing from fracture to electrical conductivity meter. When using a small rock fracture sample, it is difficult to conduct tracer tests with sufficient accuracy. Because capacity in a crack is small, influence of dead volume is large. Then, authors devised the tracer pouring method of not being influenced of dead volume. In order to check the performance of the tracer pouring method, the parallel plate with a crack width of 10cm and a crack length of 10cm made from acrylics was used, and permeability tests, tracer tests, and measurement of geometric aperture were conducted. Consequently, it was continued that a tracer tests could be conducted under sufficient accuracy by our method.