MANUAL – REFLEX EZ-TRAC™ | 80
11.2.4 Pumping
The pumping method is used for boreholes with inclinations up to 45
degrees from horizontal and for boreholes directed upwards, where
gravity is not an advantage.
This method is commonly used for underground programs were the
inclinations vary from positive to negative.
By using the core tube and locking in the core barrel, the system is
allowed to safely lock in place while the survey is being performed.
The survey system for the pumping method consists of the
REFLEX EZ-TRAC™ instrument, three aluminium extension rods and a
core adapter. A water swivel or stuffing box may also be required
depending on the inclination of the hole.
Pumping
1. Before lowering the survey system down the drill string, ensure
that the drill rods are raised from the bottom a minimum of seven
meters.
2. Thread the box end of the core adapter to the pin end of the core
tube. Tighten with pipe wrenches.
3. Gently place the survey system (instrument with three aluminium
extension rods) in the collar of the hole. Be careful to secure the
survey system to prevent it from falling into the hole.
4. Thread the pin end of the core adapter into the box end of the
aluminium extension rod and tighten with pipe wrenches.
5. Attach the water swivel or stuffing box and slowly pump the core
tube with the attached survey system into the borehole.
6. When the core tube and the back end reach the landing ring, the
back end will lock in the landing ring while the instrument extends
4.5 m/15 ft past the drill string.
7. Keep the survey system stationary at the survey station until the
measurement has been taken.
8. Slowly retrieve the core tube and the survey system. Alternatively,
continue surveying while tripping out (see the section Tripping out
above).
9. Gently lift the survey system from the hole.
10. Place the survey system in a safe position away from the
borehole and unthread the running gear.
11.2.5 Open hole surveying
Open hole surveying is used when the drill rods have been removed
from the hole. If the hole is uncased, or cased with PVC tubing or
other non-magnetic material, these holes may be surveyed.
Note, open hole surveying is high risk. Due to the existence of
cavities, irregularities and fractures as a result of bad rock formation,
the survey system risks to get struck and remain in the hole.
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