日本 地熱 学 会誌 第16巻 第4号(1994) 455頁 ～471頁 Journal of the Geothermal Research Society of Japan Vol.16, No.4 (1994) P.455-P.471 飽和率の分布を考慮 した相対浸透率の推算式 新堀雄一 ・千 田 佶 (平成5年12月2日一部発表,平 成6年1月7日 受 付,平 成6年3月2日 受 理) Estimation Equations of Relative Permeabilities Considered Saturation Distribution Yuich1 NIIBORI and Tadashl CHIDA Abstract The authors have investigated effects of distribution of saturation in a geothermal reservoir on relative permeabilities. Because the grid cells in a numerical calculation of reservoir simulation are not so small that the distributions of saturation in the cells are not assumed to be uniform. This paper proposes a model of saturation distribution , using a probability density function. The model, based on the Bernoulli trials, gives the following relation between the average value of the relative permeability for water phase, krwa and the arithmetical mean of the normalized water saturation, Sw*a : krwa = Sw*a,m (1•¬m•¬4). Also, the relative permeability of the steam phase , krga is as follows: krga =1-2Sw *a + 2Sw *a (2m+1)/3-Sw *a m (1•¬m•¬4), where m is an index representing the non-uniformity of saturation. When m equals 4, krwa and krga each agree with the , so-called, Corey's equations. Then, the saturation is assumed to be distributed uniformly in the grid cell . On the other hand, when m =1, the flow of each phase is isolated one another . The proposed correlation equations are investigated through some experimental data already reported by the authors. The equations agree quite well with the experimental results of mass transfer in water-steam flow with boiling in a porous medium. *東北 大学 工 学 部 〒980-77仙 台市青葉区荒巻字青葉 (Faculty of Engineering, Tohoku University, Sendai 980-77 Japan)