Supported engineering studies on the proposed pit walls. DGI measured the orientation and extent of joints and other points of weakness. While on site, we also supported ongoing exploration and delineation work through the collection of physical properties.
DGI assisted our client by measuring the thickness and orientation of coal seams. We also measured density, resistivity and natural gamma to assess the quality of the deposit.
Our client was conducting Pre-Feasibility stage bulk sampling program on several kimberlite bodies. Bulk sampling programs are designed to capture large samples of kimberlite to evaluate the quantity and quality of diamonds. This typically involves drilling holes between 12” and 36” in diameter, and it is important to accurately measure the diameter of the hole and calculate the volume from the different facies. DGI performed caliper measurements, profiling the hole and assisting our client with volumetric analysis. While we were on standby, we completed various geotech tasks including gyro surveys, measuring ice thickness and core logging.
Physical properties are a powerful tool in understanding kimberlites, as physical properties can vary between pipes and within facies in a kimberlite. These facies represent different eruptive events and may be associated with differing diamond grades. As physical properties can help map these facies, they are extremely useful in understanding kimberlites. DGI assisted our client by measuring density, magnetic susceptibility, acoustic velocity and natural gamma across multiple kimberlites, and associating physical property signatures with the various facies intersected. This greatly improved the understanding of the property and helped focus additional work.
DGI obtained hydrogeological and structural information for the development stage gold program.
The site is a large scale, low grade, high tonnage copper - gold deposit in Alaska. Part of the deposit is deeply buried, and geophysics can be extremely useful in targeting drillholes. Geophysics is the non-invasive investigation of the subsurface by measuring physical properties contrasts, such as magnetics, gravity, resistivity from surface. The geophysicist uses these measurements to model the size and depth of the target prior to drilling.
The drilling results are analyzed and sometimes the target is hit and sometimes the hole missed. Regardless of the outcome, it is important to capture physical properties inside the drillholes. These direct physical property measurements of the geophysical parameter used to originally target the drillhole, are used by the geophysicist to better understand why the target was hit/missed, and help guide where to drill next. DGI helped our Alaskan client with this approach to guide the drilling campaign.
DGI measured the density and magnetic susceptibility, estimating the quality and tonnage of the iron ore deposit. Gyro measurements were also performed to place the information in the correct location.
DGI supported our iron client with televiewer measurements for lithological characterization, structural analysis and rock mass conditions.
DGI was asked to measure the natural radioactivity and determine rock type, as part of a large scall uranium project. Given the complexity of the the terrain, or used a float plane to travel to camp, located on the edge of the lake.
Televiewer measurements to support geotechnical analysis to evaluate re-opening a former mine.
DGI performed geotechnical work to understand joint sets and other planes of weakness to support the pit wall design. Physical properties were also collected to support ongoing metallurgical work, to design a flowsheet to maximize recovery of the nickel.
An active mine was developing a new pit, adjacent to a lake and needed to understand the hydrogeology. The client was also concerned about the potential for swelling clays and their impact. DGI designed a program that included Nuclear Magnetic Resonance (NMR), and Spectral Gamma. NMR, is an MRI for the borehole and measures total porosity and differentiates between capillary and clay-bound fractions. It can be a very useful tool as no nuclear sources are involved and it is high resolution. DGI delivered porosity, calculated permeability, and identified clay types providing the client with the information needed to make decisions on the pit design.
Nuclear Magnetic Resonance Surveying for Permafrost Characterization in the Northwest Territories: (could use another one of our northern/winter images as long as there are no trees in the picture) DGI acquired Nuclear Magnetic Resonance data in permafrost, to measure liquid water volume. Traditional Neutron logging was not possible because of the inability to distinguish between hydrogen in liquid and solid form.
DGI acquired Spinner Flowmeter profiles downhole to locate water-bearing zones and estimate transmissivity under pumping conditions. We first acquired Acoustic Televiewer to image the borehole and see which joints were open and could potentially be an avenue for fluid flow. The client used this information to determine the location of dewatering wells, and where to set screens during well completion.
Locating water-bearing fractures and measuring their size, for a pit dewatering drill program.