1
25-085
Study on the Influence of Borehole Conditions on Panoramic
Side-View Borehole Images in Underground Coal Mines
Yuting Xue
NIOSH, Pittsburgh, PA, USA
Mark Van Dyke
NIOSH, Pittsburgh, PA, USA
Zoheir Khademian
NIOSH, Pittsburgh, PA, USA
ABSTRACT
Borehole scoping has been widely used in the U.S. under-
ground coal mines as a method for geologic mapping and
stability analysis because it is very useful for identifying rock
types, voids, fractures, and formation boundaries through
the direct observation of the borehole wall. An image stitch-
ing technique was proposed to generate panoramic bore-
hole images from side-view borescopes in a previous study.
However, the generation of panoramic borehole images can
be affected by the borehole condition because the image
stitching process highly depends on the key point detection
and matching. The presence of dust and water could have a
significant influence on the detection of key points. In this
study, the influence of borehole conditions on panoramic
borehole images was studied from the success of image
stitching and the visibility of geologic features and lithology
changes. Borehole videos recorded at different times, when
the same borehole was freshly drilled, freshly washed with
water and 12 days after washing, were processed with the
proposed technique. The comparison of the stitched images
shows that the presence of dust has minimal influence on
the image stitching process but shows significant negative
effects on the visualization of geologic feature and lithology
change. In addition, the presence of water can significantly
hinder the image stitching process, which in turn helps
in identifying lithology change. Borehole scoping aids in
identifying and mitigating hazardous conditions in under-
ground mines, and this study provides preliminary inputs
into identifying optimum borehole conditions for geologic
mapping with panoramic borehole images.
INTRODUCTION
Accurate characterization of the roof lithology within the
bolting horizon is very important for effective roof sup-
port design. Borescoping has been widely used in the U.S.
underground coal mines as a method for geologic mapping
and stability analysis. It provides an efficient and practical
method to directly observe the in-situ structures of bore-
hole wall through the optical imaging technique. Borehole
scoping can provide detailed visual information about the
lithology, structure, and any potential weak spots such as
faults, bedding planes, or inclusions, which is essential for
roof characterization and roof support design in under-
ground coal mines (Peng 2005 Iannacchione et al. 2006a,
b Bahrampour et al. 2015 Liu et al. 2018) Also, borehole
scoping can be used to assess the stability of the surround-
ing rock strata. By observing the formation of new fractures
and the opening of bedding planes, borehole scoping helps
in identifying potential instability that could pose safety
risks during mining operations.
In U.S. coal mining industry, a borehole scoping sys-
tem typically includes a video scope, a water pump, and
support poles. The water pump is used to wash boreholes
and remove the dust covering the borehole wall. The tip
of the video scope is attached to one support pole and is
pushed up by the support poles one by one. The depth is
normally marked on the support poles with a certain inter-
val, and as a result, they need to be connected following a
specific order. When scoping a borehole in underground
coal mines, it is important to have an experienced geologist
at the site for identifying and documenting the geologic
features or lithology changes and the corresponding depth.
25-085
Study on the Influence of Borehole Conditions on Panoramic
Side-View Borehole Images in Underground Coal Mines
Yuting Xue
NIOSH, Pittsburgh, PA, USA
Mark Van Dyke
NIOSH, Pittsburgh, PA, USA
Zoheir Khademian
NIOSH, Pittsburgh, PA, USA
ABSTRACT
Borehole scoping has been widely used in the U.S. under-
ground coal mines as a method for geologic mapping and
stability analysis because it is very useful for identifying rock
types, voids, fractures, and formation boundaries through
the direct observation of the borehole wall. An image stitch-
ing technique was proposed to generate panoramic bore-
hole images from side-view borescopes in a previous study.
However, the generation of panoramic borehole images can
be affected by the borehole condition because the image
stitching process highly depends on the key point detection
and matching. The presence of dust and water could have a
significant influence on the detection of key points. In this
study, the influence of borehole conditions on panoramic
borehole images was studied from the success of image
stitching and the visibility of geologic features and lithology
changes. Borehole videos recorded at different times, when
the same borehole was freshly drilled, freshly washed with
water and 12 days after washing, were processed with the
proposed technique. The comparison of the stitched images
shows that the presence of dust has minimal influence on
the image stitching process but shows significant negative
effects on the visualization of geologic feature and lithology
change. In addition, the presence of water can significantly
hinder the image stitching process, which in turn helps
in identifying lithology change. Borehole scoping aids in
identifying and mitigating hazardous conditions in under-
ground mines, and this study provides preliminary inputs
into identifying optimum borehole conditions for geologic
mapping with panoramic borehole images.
INTRODUCTION
Accurate characterization of the roof lithology within the
bolting horizon is very important for effective roof sup-
port design. Borescoping has been widely used in the U.S.
underground coal mines as a method for geologic mapping
and stability analysis. It provides an efficient and practical
method to directly observe the in-situ structures of bore-
hole wall through the optical imaging technique. Borehole
scoping can provide detailed visual information about the
lithology, structure, and any potential weak spots such as
faults, bedding planes, or inclusions, which is essential for
roof characterization and roof support design in under-
ground coal mines (Peng 2005 Iannacchione et al. 2006a,
b Bahrampour et al. 2015 Liu et al. 2018) Also, borehole
scoping can be used to assess the stability of the surround-
ing rock strata. By observing the formation of new fractures
and the opening of bedding planes, borehole scoping helps
in identifying potential instability that could pose safety
risks during mining operations.
In U.S. coal mining industry, a borehole scoping sys-
tem typically includes a video scope, a water pump, and
support poles. The water pump is used to wash boreholes
and remove the dust covering the borehole wall. The tip
of the video scope is attached to one support pole and is
pushed up by the support poles one by one. The depth is
normally marked on the support poles with a certain inter-
val, and as a result, they need to be connected following a
specific order. When scoping a borehole in underground
coal mines, it is important to have an experienced geologist
at the site for identifying and documenting the geologic
features or lithology changes and the corresponding depth.