Use of DEVICO Deep Drilling Technology at Rorys Knoll (Aurora Project), Guyana Guyana Goldfields Inc.
The Country - Guyana
Only English speaking country in South America British common law, secure tenure Highly literate population of 700,000 Pro-mining government Largely unexplored by modern methods Long history of significant gold production
History of Gold Exploration in the Guianas Guiana is a Country that hath yet her Maidenhead… not opened for gold, the mines not broken with sledges… Sir Walter Raleigh The Discovery of the Large, Rich and Beautiful Empire of Guiana, 1596 Sir Walter Raleigh
The Region
The Guiana Shield
Aurora Property, Geology Geology after Bracewell, 1949 Calebs East & West Gold Creek
Property Locations
Aurora Property The Golden Mile
Aurora Base Camp
Golden Mile Mineralized Zones Diamond Drill Holes
Rorys Knoll Diamond Drill Holes
Why DEVICO ? Constraint of 100 m x 150 m steep (70-75 deg) NNW-plunging Tonalite dimensions Historical left turns and consistent hole shallowing when drilling westwards due to regional foliation trend (NW) Problems with multiple wedging operations by Orbit drilling personnel Uncontrolled hole direction-wise
North East view of drilling operations Grid (10mX10m) for a 680m target. 4 pilot holes and 36 directional cuts
DEVICO Requirements Rig capacity on total drilled depth RPM/WOB control Mud Pump Capacity: Flow Rate- 55 l/min Pump pressure- 60 bar Drilling mud pressure gauge & flow meter Mud pump accummulator / compensator (minimize pressure/flow rate pulsation) NQ-sized inner core barrel overshot / drill pipe sub
Long Section 10700E Showing Lithology (plus blue-colored Devico directional holes)
Long Section 10700E Showing Assay Composites
Long Section 10750E Showing Lithology (plus blue-colored Devico directional holes)
Long Section 10750E Showing Assay Composites
Long Section 10800E Showing Lithology (plus blue-colored Devico directional holes)
Long Section 10800E Showing Assay Composites
Horizontal Plan View (-800 mRL)
Horizontal Plan View (-1000 mRL)
Devico directional factors Lithology (e.g. Ash Tuff Sediments) Structures (e.g. fault/foliation) Drilling parameters (e.g. hole azimuth & inclination) Target cone of influence specs per midpoint Devico target (e.g. up/down/left/right) DEVICO limits (e.g. high torque ~ 1000 m)
Devico-Orbit operations Rig mechanical problems (e.g. pump; etc.) Devico tool specs (e.g. thrust bearing; inner tube; etc.) Orbit-Devico drilling operations (e.g procedural; controlled drilling; etc.) Spare parts logistics
3-D View of Rorys Knoll Mineralization showing 100 m x 150 m Tonalite dimensions (looking North)
3-D View of Rorys Knoll Mineralization showing 100 m x 150 m Tonalite dimensions (looking East)
Devico-Orbit hole statistics RKD-60 mother hole: 9 directional cuts –Wedged/Devico-directed completed holes: RKD-60DV1/60DV2/60DV3L/60DV4R/60DV5R/ RKD-63B/RKD-67B/RKD-72B RKD-62 mother hole: 10 directional cuts –Wedged/Devico-directed completed holes: RKD-62DV1L/62DV2R/RKD-64/RKD-66/RKD-69/RKD- 71/RKD-73 RKD-63B/RKD-67B/RKD-72B Abandoned holes: –RKD-61A/61B/61C/RKD-63A/67A/72A
Summary 85 % Devico-hit on Rorys Knoll mineralized zones on 19 medium to deep directional cuts proving mineralization is open at depth Cost-savings per hole (instead of drilling holes from surface): ~ 45-50% (estimated) Successful directional cuts are mainly dependent on drilling operations personnel teamwork and still improving !!! Once good Devico techs are spotted and with proven directional performance; dont let go of them !!!