Imaging of reservoirs and fracture systems using microearthquakes induced by hydraulic injections

Conference · Tue Jan 01 04:00:00 EST 1991

OSTI ID:5526732

Fehler, M; House, L; Phillips, W S ^[1]; Block, L; Cheng, C H ^[2]

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1. Los Alamos National Lab., NM (USA)
2. Massachusetts Inst. of Tech., Cambridge, MA (USA). Earth Resources Lab.

Predicting the future performance of a geothermal reservoir and planning a strategy for increasing productivity from the reservoir require an intimate knowledge of the fracture system through which geothermal fluids permeate. Microearthquakes often accompany hydraulic fracturing as well as normal production activities in geothermal fields. The waveforms from the se microearthquakes provide valuable information that can be used to infer the three-dimensional structure of the fracture system in the reservoir. The locations of the microearthquakes can be used to infer the presence of large fractures along which shear slip has occurred. Tomographic imaging using arrival times of the seismic waves, provides a three-dimensional image of the P and S wave velocity structure of the reservoir. These velocities yield information about the presence of microfractures in the rock. Waveform stacking methods can be used to both corroborate seismic velocities and image seismic scatters in the reservoir. The most prominent seismic scatters are likely to be fluid-filled fractures. Thus, seismic data provide information about a fractures over a large scale range which can be of use in reservoir engineering. 32 refs., 4 figs.

• Research Organization: Los Alamos National Lab., NM (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 5526732
• Report Number(s): LA-UR-91-1829; CONF-911074--2; ON: DE91013368
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
150200* -- Geology & Hydrology of Geothermal Systems
58 GEOSCIENCES
580000 -- Geosciences
COMMINUTION
DIAGNOSTIC TECHNIQUES
EARTHQUAKES
FLUID MECHANICS
FLUID-STRUCTURE INTERACTIONS
FLUIDS
FRACTURING
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
GEOPHYSICAL SURVEYS
GEOTHERMAL FIELDS
GEOTHERMAL FLUIDS
Geothermal Legacy
HYDRAULIC FRACTURING
IMAGES
MECHANICS
MICROEARTHQUAKES
P WAVES
PARTIAL WAVES
S WAVES
SEISMIC EVENTS
SEISMIC SURVEYS
SEISMICITY
SUBSURFACE ENVIRONMENTS
SURVEYS
TOMOGRAPHY
WAVE FORMS
WELL LOGGING