Borehole Methods
Borehole geophysical logging and imaging is used to characterize a variety of specific subsurface conditions. NORCAL provides a complete line of fully digital state-of-the-art borehole geophysical logging and imaging techniques. The equipment is very portable and can be easily shipped to distant or difficult to reach sites, including those that require helicopter access. Our latest computer software provides a wide range of data presentation formats and sophisticated 2-D and 3-D modeling capabilities.
Techniques and typical logging objectives are as follows:
- Caliper-determine borehole dimensions
- E-Log, Induction & Guard Resistivity-define stratigraphy and stratigraphic correlations
- Sonic-access casing cement bond; P-wave velocity correlations
- P & S wave Suspension Logger-determine compressional and shear wave velocities
- Optical and Acoustic Televiewer-delineate fracture patterns and orientations and other structural features
- Heat-Pulse Flowmeter-measure vertical groundwater flow
- Deviation-determine borehole verticality
- Temperature-Differential Temperature Fluid Conductivity-determine groundwater inflow and outflow depth locations
- Discrete Water Sampling-profiling of contaminate concentration levels
- Borehole and Water Well Inspection
The following links provide detailed information regarding the various borehole logging techniques and the respective data presentation and interpretation routines.
Click on the links below to download a pdf.- Acoustic Televiewer (729kb)
- Acoustic Televiewer Analysis (880kb)
- Optical Televiewer (1.4mb)
- Optical Televiewer Analysis (1.12mb)
- Fracture Analysis (540kb)
- Stereo Analysis of Dips (1mb)
- Digital Suspension P and S Wave (924kb)
- Full Wave Form Sonic (1.5mb)
- Electric and Natural Gamma (1.23mb)
- Induction (183kb)
- Log Presentation (522kb)
- Vertical Groundwater Flow (1.1mb)
- 3D Subsurface Modeling (840kb)
- Color Borehole Video (225kb)
