Many subsequent studies using borehole log data, core data, and laboratory measurements have confirmed that an exponential relation is good approximation for relating resistivity to porosity (Jackson et al. 1978; Swanson 1979; Hilfer 1991; Ioannidis et al. 1997).
However, a subsequent hydrogeological characterisation, which involved borehole logging, grain size analyses, Natural Gamma Ray and pumping tests, revealed the presence of thin transmissive layers inside the low hydraulic conductivity materials.
Breakouts are more important due to their influences on the formation of plastic zone around borehole wall, collapse and subsequent size changes of the borehole.
Delta initiation and subsequent delta growth were investigated by using radiocarbon-dated borehole cores from the Song Hong (Red River) delta, Vietnam.
A key of the technology is to significantly increase the permeability of the overlying and underlying protected seams and subsequent gas extraction from the protected coal seams by boreholes drilled from the retained roadways (Yuan 2008).
Consequently, local thermal borehole enlargement reduces project failure risks by providing better control on subsequent stimulation processes.
The two methods most sensitive to anisotropy are found to be (1) subsequent injection from a lateral screen and from the bottom of an otherwise cased borehole, and (2) single injection from a lateral screen with an additional head observation along the casing.
A pilot hole, the KTB-VB, went to about 4 km deep, and a subsequent superdeep main hole, the KTB-HB, went to about 9.1 km deep; the two boreholes were about 200 m apart (Emmermann and Lauterjung 1997).
Twenty-six days later, the borehole went through.
A borehole is about the safest option.
