Single-Well and Cross-Well Resistivity
Exploration Technique: Single-Well and Cross-Well Resistivity
|Exploration Technique Information|
|Exploration Group:||Downhole Techniques|
|Exploration Sub Group:||Well Log Techniques|
|Parent Exploration Technique:||Well Log Techniques|
|Information Provided by Technique|
|Lithology:||Identify different lithological layers, rock composition, mineral, and clay content|
|Stratigraphic/Structural:|| -Fault and fracture identification
-Rock texture, porosity, and stress analysis
-determine dip and structural features in vicinity of borehole
-Detection of permeable pathways, fracture zones, faults
|Hydrological:||Resistivity influenced by porosity, grain size distribution, permeability, fluid saturation, fluid type and phase state of the pore water|
|Thermal:||Resistivity influenced by temperature|
|Median Estimate (USD):|| 5,000.00|
500,000 centUSD/ well
- "Downhole resistivity methods come in numerous forms and there are many different variations, configurations, and instruments used for downhole resistivity surveys. Many different companies perform single-well and cross-well resistivity surveys and countless different names have been coined for the surveys; some examples are: Formation Micro-Imager (FMI) Logs, Electric-micro Imager (EMI) Logs, Micro Resistivity, Resistivity Log, Resistivity Tomography, Fullbore Formation MircroImaging, and Formation Micro-Conductivity Imaging. '"`UNIQ--ref-00000000-QINU`"''"`UNIQ--ref-00000001-QINU`"' '"`UNIQ--ref-00000002-QINU`"' There is also a configuration called Single-point Resistance in which one electrode is placed down a well and one is on the surface.'"`UNIQ--ref-00000003-QINU`"'" cannot be used as a page name in this wiki.
- The given value was not understood.
- "Similarly to Single-Well And Cross-Well Seismic methods the downhole resistivity methods can be conducted in many different configurations. Single well resistivity methods require the transmitter and receivers to be lowered down the well on one line, so vertical cross section images of the formations immediately around the borehole can be collected. The horizontal range is dependent on the electrode spacing. With larger electrode spacing range increases, but resolution is sacrificed. The technique complements core sample data and is useful for describing intervals of a well that were not cored.'"`UNIQ--ref-00000004-QINU`"' Cross-well methods require two or more wells and are highly useful for creating cross sectional images of resistivity structures between the two wells. With cross-well methods faults, fracture patterns, and zones of permeability between the wells can be mapped.'"`UNIQ--ref-00000005-QINU`"' Single-well and cross-well resistivity is useful in geothermal exploration because down hole structural features can be revealed in high detail. This information can be very useful for siting future production wells and selecting depths for collecting core samples. Downhole resistivity measurements are useful for mapping resistivity structures, dip, porosity, rock texture, stress patterns, faults, and fractures, thus helping to create a more complete geologic model of the geothermal area and pinpointing future drilling targets.'"`UNIQ--ref-00000006-QINU`"''"`UNIQ--ref-00000007-QINU`"'" cannot be used as a page name in this wiki.
- The given value was not understood.
Single-well and cross-well resistivity is useful in geothermal exploration because down hole structural features can be revealed in high detail. This information can be very useful for siting future production wells and selecting depths for collecting core samples. Downhole resistivity measurements are useful for mapping resistivity structures, dip, porosity, rock texture, stress patterns, faults, and fractures, thus helping to create a more complete geologic model of the geothermal area and pinpointing future drilling targets.
- Well Log Techniques
- Acoustic Logs
- Caliper Log
- Chemical Logging
- Density Log
- Gamma Log
- Image Logs
- Mud Logging
- Neutron Log
- Pressure Temperature Log
- Single-Well and Cross-Well Resistivity
- [[Spontaneous Potential Well Log|Spontaneous Potential Well Log" cannot be used as a page name in this wiki.
There are many different variations of downhole resistivity logging instruments which are designed to be integrated with standard wireline technology. The instrument is lowered down the well via wireline cable and real time resistivity images can be viewed from the logging vehicle.
For a cross well resistivity survey two or more wells can be utilized. An array of electrical receivers is lowered down one well and a transmitter is lowered down another well. Typically the receiver array stays fixed and the transmitter moves between depth ranges while continuously broadcasting. After the profile is completed, the receiver array is moved to a new depth and the process is repeated. For thorough data collection this process is carried out until all source and receiver positions have been occupied for all zones of interest.
-Most instruments cannot withstand wells exceeding 175°C unless specially designed electronics or shielding is integrated into the equipment, which can drastically increase the price.
- Hemisphere Technologies. Micro-Conductivity Imager Logging Tool [Internet]. 2011. [cited 2013/10/09]. Available from: http://www.hemisphereoil.com/mcit.html
- Shakeel Ahmed. Formation Micro-Imager Logs (FMI) [Internet]. 2013. [cited 2013/10/09]. Available from: http://petphy.blogspot.com/2011/12/formation-micro-imager-logs-fmi.html
- Schlumberger. FMI Fullbore Formation Microimager [Internet]. 2013. [cited 2013/10/09]. Available from: http://www.slb.com/services/characterization/wireline_open_hole/geology/fullbore_formation_microimager.aspx
- Carole D. Johnson. Borehole Geophysical Methods [Internet]. Storrs, Connecticut. USGS. [cited 2013/10/22]. Available from: http://www.engr.uconn.edu/~lanbo/G228378Lect0511BH.pdf
- Crosswell Electromagnetic Resistivity Imaging: Illuminating the Reservior [Internet]. 2006. Middle East Asia Reservior Reviiew. [cited 2013/10/22]. Available from: http://www.slb.com/~/media/Files/resources/mearr/num7/illuminating_reservoir.pdf
- Schlumberger (Schlumberger). 2002. FMI Borehole Geology, Geomechanics and 3D Reservoir Modeling. N/A: N/A.
- Coso Geothermal Area
- Glass Buttes Area
- Maui Area
- New River Area
- Wister Area
- Alum Geothermal Area
- Fish Lake Valley Area
- Fort Bliss Area
- Long Valley Caldera Geothermal Area
- The Needles Area
- Valles Caldera - Redondo Geothermal Area
- Valles Caldera - Sulphur Springs Geothermal Area
- Crump's Hot Springs Geothermal Area
- Silver Peak Area