Site Investigation – Storage Tanks
Scanning Swimming Pool Base for Voiding
Fast effective and proven
Groundsearch are managing programs from its International Bases to diverse locations such as Mongolia,
Cambodia and Africa. We will work with you to deliver the right solution wherever your project
We have a diverse set of capabilities, and a strong base of experience in Asia and surrounds.
Grant is a qualified person to report to ASX and TSX stock exchanges. He has sign off against JORC (Australia) amd 43101 (Canada) -- we can provide more details on request
To achieve this Groundsearch uses state-of-the-art technologies, experienced senior exploration staff and in-country knowledge. This means projects that are cost effective, results driven, and locally relevant. We will work with you to deliver the right solution wherever your project may be.
Borehole geophysics has proven to be an indispensable tool for our clients in coal exploration, mineral mining, coal seam gas exploration and scientific research to name just a few. It is an incredible value-adding tool to confirm target depths, characterise overburden, assess dipping angles and much, much more.
Groundsearch uses state of the art combination tools from Century Geophysical Corporation to maximise the information gathered from the hole, while maintaining usability and the convenience to transport the equipment to operate from nearly anywhere (and over the years our clients have occasionally pushed this “anywhere” claim to extremes! – See “Our Projects”) Our most popular tools are listed here, but we can get in a tool to suit almost any endeavour very quickly.
With the backing of a huge amount of experience in exploration projects all over NZ, and a comprehensive support structure, we can manage your borehole geophysics effectively and efficiently. Email us for more information.
The Series 9239, Compensated Density logging tool uses the two focused density detectors to compute borehole compensated density real time while logging. No post processing required to produce CDL bulk density. Additionally, the tool also records natural gamma, caliper , medium guard resistivity, and borehole temperature.
The 9239 is a very well proven, diverse and reliable tool which is ideally suited for coal exploration as well as a variety of other applications. It delineates coal seams with fantastic accuracy, and can operate inside or outside the water column, and even inside or outside drill rods or casing.
The Acoustic Televiewer takes an oriented “picture” of the borehole using high-resolution sound waves. This acoustic picture is displayed in both amplitude and travel time. This information is used to detect bedding planes, fractures, and other hole anomalies without the need to have clear fluid filling the boreholes.
The televiewer digitizes 256 measurements around the borehole at each high-resolution sample interval (.005 meters/.02 feet). This data is oriented to North and displayed real-time while logging using the Visual Compu-Log software. Analysis includes color adjustment, fracture dip and strike determination, and classification of anomaly. It allows information to be displayed on the graphical screen, plot, and in report format. Optionally, the tool can be equipped with a natural gamma sensor.
The Full Wave Sonic tool contains a single transmitter and dual receiver to record formation travel times. The full wave form data is also recorded simultaneously, along with near and far travel times, borehole-compensated delta time, calculated sonic porosity, receiver gains, near/far amplitudes and natural gamma. The sonic or acoustic log uses the basic principle of sound waves traveling through a media. The Century sonic system uses a single transmitter and dual receiver system for recording the travel times of the formation. The receivers are spaced approximately 2 and 3 feet, from the transmitter. Therefore, a 0.3 m (1 ft.) calculation can be made to measure this interval transit time.
The Dipmeter tool is a formation strike and dip directional probe primarily used in mining and environmental logging applications. Additionally, the tool also records natural gamma, X-Y calipers, and borehole deviation is computed from the slant angle and bearing measurements calculated from the inclinometer and magnetometer sensors. To ensure accurate strike and dip measurements in small-diameter holes, special care should be taken when calibrating the calipers to maximize their accuracy.The image to the right shows a set of dipmeter data with “tadpoles” giving dip and dip direction of the bedding structures. The bed boundary is picked from the current logs. The boundary is then cross-correlated between each pad data and merged to give the dip of the best “plane ” through this data.
Ground penetrating radar (GPR) is a high-resolution, shallow penetrating geophysical technique.
It gives images of the underground.
Voids, cable, pipes, treasure, geotechnical targets, and geology.
Range ~1m up to 30m or more.
Figure 1, Field surveys
GPR gives accurate images of the shallow subsurface.
Applications include Non Destructive Tests (NDT’s) in construction and roading, utility location, and void detection.
It is versatile and cost effective, and Groundsearch has an impressive track record of successful surveys using GPR.
Multichannel Analysis of seismic waves
Shear Wave velocity ( Vs). Vs is one of the elastic constants , ( Young’s modulus). V
Vs is an indicator of the ground strength (stiffness) and load-bearing capacity.
A method to map soils strength without drilling.
Measure the Shear wave velocity of the soils using a geophysical survey and very smart processing.
Fill in gaps between drill holes – corelate to SPT hammer data and soil strength data.
A very powerful and fast geophysical method.
Active mode – to 25m
Passive mode to more than 100m. No need for sources uses natural ground noise source
MASW is a non-destructive method use advance or as adjunct to drilling to give soil and rock depth and soil strength.
Multi-electrode resistivity surveys allow for the collection of depth and volume information of subsurface structures through electrical measurements at the surface. This represents a versatile non-invasive method to accurately assess a wide variety of subsurface features. Electrodes are arranged in various arrays at the surface, and current is passed through the source-detector system; it is the variations in this transmitted current that is recorded. By varying the electrode separation and location we can obtain information on subsurface changes in soil resistivity and map these variations with position and depth.
Applications of ERI include mineral prospecting, monitoring of ground water flow and archaeology to name a few. It has been employed to determine the extent of saline intrusion at coastal sites, and in void assessment, especially in clay-rich conductive areas where GPR is ineffective.
Using modern equipment and good survey design this method can be rapidly applied over a large area investigating both shallow and deep soil conditions.