Terra Logging Data Services

Acoustic and Optical Televiewers are geophysical imaging logging devices, that provide high-resolution information on the location and character of secondary porosity, such as fractures and solution openings.

Televiewers also provide information on the azimuth and dip of planar features, such as fractures, bedding planes, breakout zones, mineralised structures like filled fractures and veins.

Sonic log measures the travel time of the amplitude of the elastic wave through the formation.

This information can be used to derive the velocity of elastic waves through the formation.

Full wave sonic (FWS) additionally will provide the entire sonic waveform with amplitude and travel time.

FWS most common applications are:

• Mechanical properties: rock strength and elasticity (Poisson’s ratio, bulk modulus, Young modulus, shear modulus, uni axial compressive strength TLUCS™, indentation hardeness index – TLIHI™)
• Determination of porosity (together with the gama-gamma density and neutron tools).
• Location of poor or missing cement behind casing (cement bond log – CBL).
• Fracture and permeability indication in hard rock.
• Determination of fracture aperture and permeability index.
• Provides a  record  of  “seismic”  velocity  and  travel  time  throughout  a   borehole. This information can be used to calibrate a seismic data set / synthetic seismograms (tie it in to the measured values of seismic velocity). The tool works at a higher frequency than seismic waves, therefore one must be careful with the direct comparison and application of sonic log data with seismic data.
• Stratigraphic correlation.
• Identification of lithology.
• Facies recognition.
• Identification of compaction.
• Identification of over-pressures.
• Identification of source rocks.

The gamma gamma density tool measures the electron density of the geological formation, adjacent to the borehole, using Compton Scattering effect of the gamma rays. Electron density can be converted to bulk density.

Density is the single most important geophysical measurement. Therefore, an accurate bulk density is pillar to all subsequent geophysical, petrophysical, geological and geotechnical interpretation.

Two main different types of tools are available: single and dual detector density tools. Both tools have their limitations and strengths.

We provide unique corrections and compensation algorithms for electron density, borehole rugosity, any size steel casing and RC drill rods.

Corrections are uniquely designed for any single and dual density tool design.

A borehole rugosity correction applied on a dual density detector tool, independently on short and long space detector responses will bring back valuable information otherwise lost.

Borehole rugosity correction identifies thin beds and ore nuggets density.

Single and dual density calibration programs from design to implementation for in house and onsite use.

Broad experience in mineral, oil and gas industry, on three continents Europe, North America and Australia.

Over 30 projects in  iron ore, gold, Lithium and coal deposits geophysical, geological, geotechnical and petrophysical interpretation.

Successfully developed the first dual density production program for the largest iron ore Australian producer, from initial technical design, production implementation to calibration procedures.

Customized televiewer data processing and interpretation courses to the general community as well as specific in-house courses to companies and acquisition and processing contractors

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