抄録
In this paper, we discussed the relationship between velocity and effective porosity with the effects of the clay minerals. The relation between velocity and porosity is shown on the crossplot (Fig. 1); the velocity generally increases as the porosity decreases but the data are so dispersed that we are not able to come up with an equation that exhibits strong linear relation between velocity and porosity. We supposed that the existence of clay is the cause of this dispersion. We determined the area of the data by two equations: one equation expresses the relation between the velocity and porosity for clean sandstone and another expresses the relation between the velocity and effective porosity of 100% clay minerals in the pore space. The effective porosity is moved between two lines.
Using the technique of well log interpretation, we estimate the volume of bound water and show the effects of clay minerals for the relationship between velocity and effective porosity.
The velocities of shale show the effects of velocity reduction due to clay minerals.
