インダクション-ソニック-マイクロラテロログよりの油層評価
1967 年 32 巻 6 号 p. 336-346
詳細
1967 年 32 巻 6 号 p. 336-346
In this paper, the authors expained log interpretation of Induction-Sonic-Microlatero logging system for shaly sand deposited at the depth of shallower than 3, 000 meters in Niigata prefecture, Japan. The sands which were dealt with, were considered to be medium degree of hardness and from medium to slight degree of shaliness. The results of log interpretation from such sands were concluded as follows;
1) With gas reservoir, sonic transit time ΔT of sand appreciably increased due to gas effect and, also, it was of interest that ΔT of water formation which had residual gas saturation had a similar effect as gas reservoir. As regarding the data dealt here, it was necessary to use some correcting factor for gas effect, in the case of calculating porosities.
2) The relation between porosity and formation resistivity factor for the sand followed the wellknown Humble's formula.
3) As for the method of ploting Sonic transit time vs. depth for evaluating formation pressure, it was very useful, but, on the standpoint of field application, the authors thought that there existed in some cases the plot of ΔT sh vs. depth was more preferable than that of log (ΔTsh) vs. depth.
