|
In addition to the numerous surface
geophysical services we provide, Hager-Richter
also offers a full suite of down hole geophysical methods to meet our
client's specific needs. Geophysical borehole logging involves measuring
the physical properties of the surrounding medium with a sensor located in
a borehole. Down hole geophysical measurements are made in situ and thus
can provide highly accurate information about subsurface properties.
Down hole methods also provide a means of correlating geological formations
from one borehole to another. A variety of geologic information can be
obtained from down hole surveys.
Borehole geophysical logging can
provide information about:
- lithology
- formation thickness
- dip of strata
- location and attitude of fractures
- presence of water-bearing fractures
- formation fluid content
- condition of well casing
- depth of bottom of casing
- sediment porosity/permeability
- subsurface temperature
- depth of water table
|
Video logging can be used to determine:
- casing conditions
- rock socket conditions
|
|
 |
|
|
Hager-Richter owns and operates the ISL Spectrum 100 PTZ camera
(pictured at left),
manufactured by Inuktun. The PTZ series camera has a number of
advantageous characteristics:
|
Depth Rating |
200 feet, Salt or Fresh Water |
| Lens |
72:1 Zoom (18X Optical, 4X Digital) |
| Illumination |
3 lux, Variable Intensity |
| Pan Range |
340°
Mechanical (360°
Visible) |
| Tilt Range |
270° |
| Control System |
- Variable Speed Joystick Pan & Tilt Control
- Can produce in-field display |
|
The parameters measured by borehole logging depend on the instruments
used and the data required. Parameters may include temperature,
seismic velocities, natural radioactivity, various electrical properties,
and diameter of the borehole.
|
General applications |
Specific Applications |
- municipal and industrial groundwater supply investigations
- construction/engineering applications
- environmental audits and site assessments
- evaluation of active and inactive industrial facilities
- public/private remedial investigations and feasibility studies
- geological studies
- mining applications
|
- determine lithologies and their physical properties
- locate zones of contamination
- test well casing integrity
- locate water producing zones
- correlate stratigraphy
- locate productive rock fractures
- locate clay layers in overburden
- locate zones for hydrofracing
- locate pegmatites, radioactive ores, and base metals
|
Hager Richter has extensive experience with Acoustic Televiewer (ATV)
logging. We own a Mount Sopris MGX-II Slim Borehole Geophysical
Logging System and are also equipped to provide fluid temperature, fluid
resistivity, 3-arm caliper, heat pulse flow meter, electromagnetic
induction, natural gamma ray, normal resistivity, single point resistance,
and spontaneous potential surveys. Our custom-built borehole video
logging system uses a high resolution submersible video camera with depth
capability greater than 200 feet and an 18X optical (4X digital) zoom.
|
It is our standard practice to provide an interpretation of the
borehole logging data. Most other firms provide only the logs
to their clients. Our decades of experience and years of
research allow us to provide our clients with a clear and concise
description of the results, as well as an honest assessment of the
limitations. |
 |
|
Borehole Logging Case Study |
| Problem:
Our client sought to develop a detailed
groundwater flow model to project the movement of contaminant at a
Superfund Site owned by a major defense contractor in the
Northeastern U.S.. The correlation and continuity of clay
layers in the overburden was a critical factor in the model.
The site was large and geologically complex. Solution:
We logged
dozens of wells for gamma radiation to locate the clay layers and
for temperature to determine where the water was entering the wells.
Data from the borehole logging program was used to construct more
accurate geologic cross-sections and to fine tune the groundwater
flow model of the site, helping our client resolve several questions
without needing to install many more borings. |
|
