Drill hole measurement – precise information about the depths of the earth
Drill hole measurements supplement information received from the drill hole, providing valuable extra information about the soil – about the ore deposit and rock integrity. Accurate hole measurement is the key to finding the core samples wanted. With the right equipment we can measure precisely the depth, angle and possible branches of the drilled hole.
Accurate drill hole measurements
When planning extraction and making orebody estimates, it is important for the locations of the core sample and potential ore deposit to be precisely determined. When drilling, our measurement team provides fluent drill hole measurements, also for old drill holes if necessary.
Accurate results from deviation surveys
Deviation surveys can accurately determine the course and end point of the drill hole. The deviation survey is usually conducted after the completion of a hole, but with deep or branched holes, the survey can be conducted several times at the desired interval. Would you like to learn more about our deviation survey services? Contact us!
Hydrological measurements as part of preparation for mining
To really understand everything about mining and especially the safety part of mine development, you need to know how to control the water in the ground. Before mining, you need to know where the groundwaters are and where they connect to other sources.
Water pressure surveys provide data on rock integrity
Water pressure surveys specify the integrity of the rock to be surveyed. Water pressure surveys provide extra information about the fragmented zones in the bedrock and the scale of such. The measurement findings can be calculated as Lugeons.
Surface measurements and borehole surveys
Our measurement services also include the locating of boreholes in the earth using a precision GPS device, and the measurement of boreholes’ start azimuth once drilling is complete. We offer high quality borehole survey services. Contact us, if you’re interested in our borehole survey expertise!
The equipment we use for directional surveys in hole measurement
SPT Gyromaster for borehole measurement
This is high-end true north tool that provides location data in relation to the Geographic North Pole. It provides the best possible accuracy of measurement – no other equipment is needed!
Northseeking Gyro is suitable for measuring all kinds of boreholes but it is particularly useful in measuring deep and branched holes.
Reflex Gyro for measuring old boreholes and in mines
This electronic gyro device is a good all-round tool for most situations. The device can be practically used for measuring old boreholes without the need for bringing the drill rig to the site. Reflex Gyro is also suitable for measurements in underground mines.
Devico Deviflex for more shallow holes
This is an extremely easy-to-use, non-magnetic device for all kinds of measurements. Devico Deviflex is especially handy for shallow holes and daily use.
What is deviation survey?
Borehole deviation survey is also known as directional survey. The survey is an accurate way to measure both directional and straight drill holes. Directional borehole survey is usually conducted when the hole is completed, but the survey can also be conducted several times if the drillhole is deep or branched.
Deviaton survey or directional survey is done to determine the angle of the deviation during drilling. The survey can be completed with two different instruments: first type reveals only the drift angle of the drillhole, and the other one indicates both the angle and the direction.
When you want to be sure of the best possible results, contact us and ask about all-inclusive drill hole measurement services.
What is drill hole deviation and how do you prevent hole deviation?
While diamond drilling, excessive feed pressure can cause the drill bit to tilt, which then can cause hole deviation when the drill’s bit pivots during rotation. Hole deviation is the unintentional departure of the drill bit from a preselected drillhole trajectory.
We can prevent hole deviation with active drill hole measurements and deviation surveys. In the process of planning, to get to the target with as less hole deviation as possible, ensuring the correct wellbore path and knowing it’s position is important. In preventing drill hole deviation it’s also important to set up the drill rig in the exact right place and to be aware of geological conditions such as fractured rocks, that can impact the drill.
Why are deviation surveys required?
During drilling, deviation surveys are taken periodically to ensure that the drill hole will hit it’s target. Drill hole surveys also make sure that even a branched drill hole is still in the proper area, if there is a possibility for it to trespass different property.
When doing drill hole surveys during drilling, we can also determmine geological and geotechnical parameters along the way to the main target.
