Survey and Ori Tools

Don MacDonaldRegional Manager Victoria

1. Survey Tools1. Magnetic2. Gyroscopic3. Magnetic Ground

2. Orientation Tools1. Mechanical2. Core Barrel orientation

3. Limitations

Drill hole surveys1. Drill holes will corkscrew naturally

(Steep hole)2. Involve the drillers when planning

a deep hole to a small target3. Every 30m – diamond holes4. Every 50m – RC holes

Magnetic Survey ToolsMust run in a non magnetic environment1. Mechanical (Magnetic compass and a film)2. Electronic

A. Gravity accelerometers (Measure Inclination / Dip)B. Fluxgate magnetometers (Measure Direction / Azimuth)

Eastman Camera

Magnetic Survey Tools - Electronic

SingleshotMultishotExamples• Devishot• Reflex Ez-Trac, Ez-Shot, Maxibore• Globaltech Pathfinder• 2IC - Verti-Ori (vertical holes)

Gyroscopic Survey ToolsUsed when there is external magnetic interference (casing, magnetic rocks, etc).1. Spinning wheel on a shaft (40,000 RPM) within a Gimbal2. Wheels inertia keeps it facing the same direction

1. Wheel is constant in space – but the earth is moving (360 degrees in 24 hours)

3. Usually run with a multishot survey tool

Surveys in Magnetic Ground• Require a starting reference azimuth• Gyroscope Surveys• DeviFlex

– Non Gyro (Accelerometers and strain gauges)

• Reflex Maxibore

Surveys - Traps for young players1. Surveying a near vertical hole will give a large range of azimuth readings2. Cleavage, bedding or faults can cause the hole to “naturally” deviate3. Dip readings can be taken in Magnetic ground4. Azimuth readings in magnetic ground require specialised equipment (gyro) 5. Geos should give the drillers guidelines to work to (i.e. +/- 2 degrees /

100m)6. Record the magnetic reading to determine if a survey is reliable

Orientating CoreRequire:

A. Survey of the Hole (Dip and Azimuth)B. Collar of the hole (X, Y, Z co-ordinates)C. Bottom (or top) of the core must be marked

Orientation Tools1. Mechanical

1. Orientates core BEFORE its drilled2. Marks the core that is still in the ground

2. Core Barrel Orientation1. Orientates core AFTER its drilled2. Orientates the core barrel3. Electronic and Mechanical

Electronic Orientation Tools1. Reflex ACT III (ACE Tool)2. Adam Oritools3. Devico Devicore4. GlobalTech Orifinder5. Boart Longyear Trucore

Core Barrel Orientation Tools1. The mark is placed by the driller on the last piece of core drilled2. Assumes that the last piece of core is attached to the country rock3. Mostly electronic4. 2IC EZI-Ori is mechanical

Mechanical tools1. Spear 2. Ezy-Mark3. Scribe knife (Survey and Ori)

Orientations - Traps for young players1. Orientations are not good in broken ground2. The geo must understand the orientation system used

a) i.e. core barrel tool, core may move in the barrel

3. Audit the tool and the processa) Regular, standard, benchtop checks

4. Check repeatability - Line up three marks in a row5. Check the ori line every run and give immediate feedback to the drillers6. A small amount of good data is better than lots of bad data

Incorrect Orientations

Bouncing Spear, exploding pencil