Exploration Technique: Microgravity-Hybrid Microgravity
|Exploration Technique Information|
|Exploration Group:||Geophysical Techniques|
|Exploration Sub Group:||Gravity Techniques|
|Parent Exploration Technique:||Gravity Techniques|
|Information Provided by Technique|
|Stratigraphic/Structural:||Ground subsidence can be mapped using microgravity|
|Hydrological:||Monitoring net mass changes of a geothermal reservoir due to production and reinjection processes|
|Thermal:||Changes in liquid density due to temperature changes in the reservoir|
|Low-End Estimate (USD):|| 50.005,000 centUSD |
5.0e-8 TUSD / station
|Median Estimate (USD):|| 61.676,167 centUSD |
6.167e-8 TUSD / station
|High-End Estimate (USD):|| 115.0011,500 centUSD |
1.15e-7 TUSD / station
|Low-End Estimate:|| 0.30 days8.213552e-4 years |
0.00986 months / 10 stn
|Median Estimate:|| 0.36 days9.856263e-4 years |
0.0118 months / 10 stn
|High-End Estimate:|| 1.20 days0.00329 years |
0.0394 months / 10 stn
|Cost/Time Dependency:||Location, Size, Resolution, Terrain, Weather|
Microgravity surveys produce contour maps of gravity changes, through which regions of net mass loss or gain can be identified over a specified time period in between measurements.
For instance, at the Wairakei geothermal field in New Zealand, the ground subsidence achieved a maximum vertical ground movement of 11 m in one area of the field. Additionally, the maximum subsidence rate (in mm/yr) between gravity measurements may be calculated. 
• Microgravity measurements should be recorded outside the boundary of the known geothermal field as well in order to characterize the fluid flow upon reinjection.
• The frequency of reoccupation of the microgravity stations should be greater during the initial production of the field, when the largest changes may be anticipated.
• Microgravity data should be applied in conjunction with numerical reservoir simulation models. 
No exploration activities found.