Browsing Earth and Ocean Sciences by Issue Date
Now showing items 1-20 of 34
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Electron backscatter diffraction (EBSD) in the SEM: applications to microstructures in minerals and rocks and recent technological advancements
(Sociedad Española de la Mineralogía, 2008-09-16)Electron backscatter diffraction (EBSD) is based on the principle that a beam of electrons generated in the scanning electron microscope (SEM) is the source of randomly scattered electrons in a specimen. The backscattered ... -
Fractures interpreted from acoustic formation imaging technology: Correlation to permeability
(Stanford University, 2011-01-31)Permeable feed zones in geothermal wells are commonly identified using well profiles of temperature, pressure and fluid velocity measured at different injection rates during well completion testing and heat-up. While this ... -
Statistical corrections of fracture sampling bias in boreholes from acoustic televiewer logs
(New Zealand Geothermal Workshop, 2012)Targeting structurally controlled permeability remains a challenge in high temperature geothermal fields, because of the difficulties in characterising faults and fractures and their behaviour within the reservoir. The ... -
Quantifying the stress distribution at the Rotokawa Geothermal Field, New Zealand
(New Zealand Geothermal Workshop, 2012)Knowledge of the orientation and magnitude of the principal stresses can be used to model the behavior of faults and fractures, and determine how they may influence fracture hosted permeability in geothermal reservoirs. ... -
The nature of fracture permeability in the basement greywacke at Kawerau Geothermal Field, New Zealand
(Stanford University, 2012-01-30)The Mesozoic basement at Kawerau Geothermal Field comprises well indurated, inter-bedded sandstones and argillites with a complex structural history. These rocks have very low matrix porosity but nonetheless host both ... -
Fabrics produced mimetically during static metamorphism in retrogressed eclogites from the Zermatt-Saas zone, Western Italian Alps
(Elsevier, 2012-09-12)Lattice preferred orientations (LPOs) are commonly interpreted to form by dislocation creep. Consequently they are used to infer deformation at the metamorphic grade at which the minerals were stable, especially if those ... -
Late-interseismic state of a continental plate-bounding fault: Petrophysical results from DFDP-1 wireline logging and core analysis, Alpine Fault, New Zealand
(American Geophysical Union (AGU), 2013)We present a geophysical characterization at 0.1-100 m scales of a major plate-bounding continental fault in a late-interseismic state. The Alpine Fault produces M-W approximate to 8 earthquakes every 200-400 years and ... -
A7 Makaroro River dam site Phase 1C: Field characterisation of possible secondary fault displacement
(GNS Science, 2013)GNS Science has undertaken a field study to investigate the possibility of active secondary faulting in the vicinity of the proposed A7 dam site on the Makaroro River, central Hawke’s Bay. The A7 site is located c. 750 ... -
An energy-driven geologist
(The New Zealand Association of Scientists, 2013)[No abstract available] -
Interpretive review of the acoustic borehole image logs acquired to date in the Wairakei-Tauhara Geothermal Field
(Institute of Geological and Nuclear Sciences Limited, 2013)[No abstract available] -
A damage mechanics approach to modeling failure in Greywacke rock
(New Zealand Geothermal Workshop, 2014)Fracture networks within greywacke basement rocks often control fluid flow in geothermal reservoirs in New Zealand. Thermal, hydrological, chemical, and mechanical processes affect the evolution of these fracture networks. ... -
Rock properties of Greywacke Basement hosting geothermal reservoirs, New Zealand: preliminary results
(Stanford University, 2014-02-24)Geothermal resources in New Zealand are known to be hosted in greywacke basement rocks. Fluid flow in these reservoirs and the wells that access them is controlled by fracture networks. As such it is of vital importance ... -
Processing and analysis of high temperature geothermal acoustic borehole image logs in the Taupo Volcanic Zone, New Zealand
(Elsevier, 2014-06-19)Acoustic borehole televiewer (BHTV) logs provide direct observations of lithology, structure and in-situ stress in reservoirs, essential for successful well targeting and field management. Analyses of BHTV logs acquired ... -
Fracture geometries and processes in andesites at Mt Ruapehu, New Zealand: implications for the fracture modelling of the Rotokawa Geothermal Field
(Le Consortium Gocad, 2014-09-16)Fluid flow in the high-temperature (300 C), andesite-hosted Rotokawa geothermal reservoir (Taupo Volcanic Zone (TVZ), New Zealand) is largely controlled by fractures and faults but their geometries are still poorly ... -
Heterogeneity of structure and stress in the Rotokawa Geothermal Field, New Zealand
(American Geophysical Union (AGU), 2015-02-12)Geometric characterization of a geothermal reservoir's structures, and their relation to stress field orientation, is vital for resource development. Subsurface structure and stress field orientations of the Rotokawa ... -
Comparing borehole televiewer logs with continuous core: An example from New Zealand
(International Geothermal Association, 2015-04-19)The use of borehole televiewer logging is a recent addition to the well logging toolkit available to the geothermal industry in New Zealand. The information acquired from borehole televiewer (BHTV) equipment, such as the ... -
Fracture width and spacing distributions from borehole televiewer logs and cores in the Rotokawa Geothermal Field, New Zealand
(International Geothermal Association, 2015-04-19)The successful targeting of permeable fractures in geothermal fields is aided by understanding the spatial and geometric characteristics of fracture populations. Studies of numerous outcrop, and a limited number of geothermal ... -
New Zealand geothermal power plants as critical facilities: an active fault avoidance study in the Wairakei Geothermal Field, New Zealand
(International Geothermal Association, 2015-04-19)Active faults in rifts commonly provide high crustal permeability and control geothermal fluid pathways. However, active faults can also pose surface deformation hazards to geothermal power plants and associated infrastructure. ... -
A review of the Rotokawa Geothermal Field, New Zealand
(Elsevier, 2015-07-29)The Rotokawa Geothermal Field of New Zealand has seen significant development over the last 20 years and has been the study site for new and innovative geological and geothermal research. This includes the one of the first ... -
Feasibility of storing carbon dioxide on a tectonically active margin: New Zealand
(American Association of Petroleum Geologists, 2015-09-13)New Zealand's sedimentary basins was found to have available several gigatonnes of CO2 storage capacity. However, CO2 storage is currently untested in New Zealand. The country's position on an active Neogene plate boundary ...