FEATURE
Improving Borehole Survey Accuracy in Mining Exploration
The importance of using the correct gyro survey tools and quality controls for borehole trajectory accuracy in mining exploration projects
Today , when it comes to the
exploration of mineral and raw materials in the mining industry , the measurement of the trajectory during drilling – both in the exploration phase and in production – is a key factor that those responsible for the geology , drilling , and planning departments must take into account . Even a slight error in the planning phase can result in the deviation of the well ( or borehole ), missing the final target body .
Many companies and investors fund mineral deposit exploration projects that initially seem very promising . However , as they advance , the results do not always coincide with what was expected . One of the most common causes of this occurrence is the well trajectory missing the target during drilling the borehole . Likewise , the use of incorrect gyro survey technologies , combined with the lack of a robust quality control process used in the selection and operation of these tools , can also result in the well trajectory being off-target .
Further , the use of standard data synchronization programs in conventional systems often starts from the final data . In comparison , the technology implemented by Stockholm Precision tools ( SPT AB ) is based around a rigorous calibration control process for each tool , in addition to measurement checks that compare the In-Run & Out-Run data , which is then automatically processed by the SPT software . Stockholm Precision Tools is the only company in this field of exploration drilling , whose tools are equipped with this intensive quality control process , with the objective of protecting the client ’ s investment .
When it comes to mining exploration , investors seek to obtain the best possible results from their mining projects , whether the target ore is present at
Figure 1 . GyroMaster™
the said location , or not . This provides them with the required returns to the capital they have invested for the mining project . Unfortunately , this is not always the case .
All too frequently , exploration projects overlook the importance of a Quality Assurance , Quality Control ( QA / QC ) Program for the positional survey data from the start . This is important because the data obtained from the geospatial location and the core sample in its exact origin are key to determine the existence or not , of the target mineral , on which the economic viability of the project heavily depends upon .
Advantages of using the correct gyro survey tool An important factor that can affect the quality of a recovered core body sample is the wrong choice of the gyro survey tool , which is often chosen solely based on its price . A detailed analysis is needed around the question : What is
Figure 2 . Core Retriever™ more expensive : renting high-precision true north seeking gyros , such as SPT GyroMaster ™ and Core Retriever™ ( Fig . 1 and 2 ), or the incorrect evaluation of mineral reserves due to the use of a low cost and unreliable gyro survey tool ? gyromaster solid state north seeking gyro instrument
SPT GyroMaster™ : High accuracy True North Seeking Gyro Survey Tool
What is a Gyroscope ? The gyroscope is defined as an object that is in rotation , with two fundamental properties : gyroscopic inertia or “ stiffness in space ” and precession , which is the inclination of the axis at right angles to any force that tends to change the plane of rotation . These properties are inherent in all rotating bodies , including Earth .
Gyroscopic inertia and the force of gravity can be used to make the gyroscope function as a directional indicator or compass . If you consider a gyroscope mounted on the Earth ’ s equator , with its axis of rotation located in the east-west plane , the gyroscope will continue to point in that direction as the Earth rotates from west to east . Thus , the eastern end will ascend relative to Earth , although it will continue to point in the same direction in space .
This resistance or compensation in force makes an opposing movement around the vertical axis , towards the meridian , so that the axis of the gyroscope always points to the true meridian ( or to the true north ).
Due to its operation being based on the rotational force of the Earth and not on magnetism , the GyroMaster™ has multiple applications and its use is increasingly widespread in geology and major mining exploration projects .
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