core orientation in vertical holes. vertical hole in portugal ground investigation for mine shaft...
TRANSCRIPT
![Page 1: Core orientation in vertical holes. Vertical hole in Portugal Ground investigation for mine shaft 1250m deep (planned) 5m radius Drillcon drilling contractor](https://reader035.vdocuments.us/reader035/viewer/2022070412/56649e975503460f94b9aaea/html5/thumbnails/1.jpg)
Core orientation in vertical holes
![Page 2: Core orientation in vertical holes. Vertical hole in Portugal Ground investigation for mine shaft 1250m deep (planned) 5m radius Drillcon drilling contractor](https://reader035.vdocuments.us/reader035/viewer/2022070412/56649e975503460f94b9aaea/html5/thumbnails/2.jpg)
Vertical hole in Portugal
• Ground investigation for mine shaft• 1250m deep (planned)• 5m radius• Drillcon drilling contractor• Devico
• Directional core drilling• Core orientation
![Page 3: Core orientation in vertical holes. Vertical hole in Portugal Ground investigation for mine shaft 1250m deep (planned) 5m radius Drillcon drilling contractor](https://reader035.vdocuments.us/reader035/viewer/2022070412/56649e975503460f94b9aaea/html5/thumbnails/3.jpg)
Borehole specifications
• Core orientation required in project specifications
• Devico offered the DeviCore system, but mainly as a ”steering” tool to keep track of borehole inclination. Core orientation would be possible if inclination was above -88.5°.
![Page 4: Core orientation in vertical holes. Vertical hole in Portugal Ground investigation for mine shaft 1250m deep (planned) 5m radius Drillcon drilling contractor](https://reader035.vdocuments.us/reader035/viewer/2022070412/56649e975503460f94b9aaea/html5/thumbnails/4.jpg)
DeviCore system
• Continuous orientation• Scratchers marks the core during drilling
• Single point orientation• The core is marked on surface after drilling
![Page 5: Core orientation in vertical holes. Vertical hole in Portugal Ground investigation for mine shaft 1250m deep (planned) 5m radius Drillcon drilling contractor](https://reader035.vdocuments.us/reader035/viewer/2022070412/56649e975503460f94b9aaea/html5/thumbnails/5.jpg)
DeviCore principal
DeviCore 0° tool face aligned with master scratcher/mark
![Page 6: Core orientation in vertical holes. Vertical hole in Portugal Ground investigation for mine shaft 1250m deep (planned) 5m radius Drillcon drilling contractor](https://reader035.vdocuments.us/reader035/viewer/2022070412/56649e975503460f94b9aaea/html5/thumbnails/6.jpg)
Drilling equipment
• Atlas Copco Corac N3/50 core barrel• 3m inner tube with split tubes• 50mm core
![Page 7: Core orientation in vertical holes. Vertical hole in Portugal Ground investigation for mine shaft 1250m deep (planned) 5m radius Drillcon drilling contractor](https://reader035.vdocuments.us/reader035/viewer/2022070412/56649e975503460f94b9aaea/html5/thumbnails/7.jpg)
DeviCore in Corac
• Difficult to accommodate the DeviCore in the split tubes
• DeviCore takes up 1 meter of the inner tube
• Solution: 1.5m extension behind the inner tube/split tubes and on the core barrel
![Page 8: Core orientation in vertical holes. Vertical hole in Portugal Ground investigation for mine shaft 1250m deep (planned) 5m radius Drillcon drilling contractor](https://reader035.vdocuments.us/reader035/viewer/2022070412/56649e975503460f94b9aaea/html5/thumbnails/8.jpg)
Core orientation
Mark on the inner tube corresponds with DeviCore
![Page 9: Core orientation in vertical holes. Vertical hole in Portugal Ground investigation for mine shaft 1250m deep (planned) 5m radius Drillcon drilling contractor](https://reader035.vdocuments.us/reader035/viewer/2022070412/56649e975503460f94b9aaea/html5/thumbnails/9.jpg)
Core orientation cont.
• Drill 3m as normal• Reduce or remove water
flow• Instrument reading
before breaking the core
![Page 10: Core orientation in vertical holes. Vertical hole in Portugal Ground investigation for mine shaft 1250m deep (planned) 5m radius Drillcon drilling contractor](https://reader035.vdocuments.us/reader035/viewer/2022070412/56649e975503460f94b9aaea/html5/thumbnails/10.jpg)
Core orientation cont.
Mark the core at 0° tool face and pump the split tubes
![Page 11: Core orientation in vertical holes. Vertical hole in Portugal Ground investigation for mine shaft 1250m deep (planned) 5m radius Drillcon drilling contractor](https://reader035.vdocuments.us/reader035/viewer/2022070412/56649e975503460f94b9aaea/html5/thumbnails/11.jpg)
Core orientation cont.
Mark the core according to tool face reading (shows up)
![Page 12: Core orientation in vertical holes. Vertical hole in Portugal Ground investigation for mine shaft 1250m deep (planned) 5m radius Drillcon drilling contractor](https://reader035.vdocuments.us/reader035/viewer/2022070412/56649e975503460f94b9aaea/html5/thumbnails/12.jpg)
DeviCore results
• Core orientation has worked (surprisingly) well
• Good results achieved even at inclinations down to -89.3°
• Normal error 0°-10°• Maximum error about 30°-40°• All orientation work performed by the drillers
![Page 13: Core orientation in vertical holes. Vertical hole in Portugal Ground investigation for mine shaft 1250m deep (planned) 5m radius Drillcon drilling contractor](https://reader035.vdocuments.us/reader035/viewer/2022070412/56649e975503460f94b9aaea/html5/thumbnails/13.jpg)
Understanding the orientation
• Some issues getting the core loggers to understand the orientation
• Making the orientation line from the reference mark
• Vertical hole gives rapid changes in azimuth which moves the orientation line over the rock structures
![Page 14: Core orientation in vertical holes. Vertical hole in Portugal Ground investigation for mine shaft 1250m deep (planned) 5m radius Drillcon drilling contractor](https://reader035.vdocuments.us/reader035/viewer/2022070412/56649e975503460f94b9aaea/html5/thumbnails/14.jpg)
Directional core drilling
• High natural deviation
• Soft and fractured rocks
• Dogleg setting of 6!!
• 5 DeviDrill corrections
before 450m