Online Journal for E&P Geoscientists

Kasahara, Junzo ^*1; Ito, Shinji ¹; Hasada, Yoko ²; Takano, Masanori ¹; Andre, Guidi ¹; Fujiwara, Tomohiro ¹; Tsruruga, Kayoko ³; Fujii, Naoyuki ⁴
(1) Science System Solution, NTT-DATA-CCS Co. Ltd., Tokyo, Japan. (2) Daiwa Exploration and Consulting Co. Ltd., 2-2-11 Furuishiba, Kouto-ku, Japan. (3) Marine Science, Tokyo University of Marine Science and Technlology, 4-5-7 Kounan, Minato-ku, Tokyo, Japan. (4) Department of Science, Shizuoka University, 836 Oya,Shizouka, Japan.

In order to watch the temporal change of the physical states of oil/gas/CO2 reservoirs, it is important to develop technologies for the accurate 4D(time-lapse) monitoring. For these objectives, we use ultra-stable seismic source called ACROSS and multi-geophones. Using newly developed seismic ACROSS, we examined the waveforms of observed 32-three component geophones exited by the ACROSS in Awaji Island. The seismic ACROSS can generate seismic signals from 10 to 50Hz with 40 ton-f at 50Hz. By the addition and the subtraction of clockwise and anti-clockwise rotations of the eccentric weigh-mass of the ACROSS, we obtained transfer functions between a source and a receiver for vertical force and horizontal forces. It is found that addition and subtraction process of clock and anti-clock rotation records can satisfactory generate P and S wavers, respectively.