Near-Surface Geothermal Reservoir Imaging based on the Customized Dense Seismic Network

2021 ◽  
Author(s):  
Changjiang Zhou ◽  
Jianghai Xia ◽  
Jingyin Pang ◽  
Feng Cheng ◽  
Xinhua Chen ◽  
...  
Keyword(s):  
Seismic Network ◽  
Geothermal Reservoir ◽  
Near Surface

scholarly journals Passive seismic experiment “AniMaLS” in the Polish Sudetes (NE Variscides)

2021 ◽  
Vol 10 (2) ◽  
pp. 183-202
Author(s):  
Monika Bociarska ◽  
Julia Rewers ◽  
Dariusz Wójcik ◽  
Weronika Materkowska ◽  
Piotr Środa ◽  
...  
Keyword(s):  
Seismic Anisotropy ◽  
Geological Structure ◽  
Seismic Network ◽  
Data Quality Control ◽  
Crust And Upper Mantle ◽  
Near Surface ◽  
Correct Orientation ◽  
Seismic Experiment ◽  
Upper Mantle Structure ◽  
Passive Seismic

Abstract. The paper presents information about the seismic experiment “AniMaLS” which aims to provide a new insight into the crust and upper mantle structure beneath the Polish Sudetes (NE margin of the Variscan orogen). The seismic network composed of 23 temporary broadband stations was operated continuously for about 2 years (October 2017 to October 2019). The dataset was complemented by records from eight permanent stations located in the study area and in the vicinity. The stations were deployed with an inter-station spacing of approximately 25–30 km. As a result, recordings of local, regional and teleseismic events were obtained. We describe the aims and motivation of the project, the station deployment procedure, as well as the characteristics of the temporary seismic network and of the permanent stations. Furthermore, this paper includes a description of important issues like data transmission setup, status monitoring systems, data quality control, near-surface geological structure beneath stations and related site effects, etc. Special attention was paid to verification of correct orientation of the sensors. The obtained dataset will be analysed using several seismic interpretation methods, including analysis of seismic anisotropy parameters, with the objective of extending knowledge about the lithospheric and sublithospheric structure and the tectonic evolution of the study area.

Characterization of geothermal reservoir crack patterns using shear‐wave splitting

Geophysics ◽  
1997 ◽  
Vol 62 (2) ◽  
pp. 487-494 ◽  
Author(s):  
Min Lou ◽  
J. A. Rial
Keyword(s):  
Density Distribution ◽  
Shear Wave ◽  
Time Delays ◽  
Shear Wave Splitting ◽  
Seismic Network ◽  
Geothermal Reservoir ◽  
Fracture Density ◽  
Crack Patterns ◽  
Wave Splitting

Microearthquakes recorded by a downhole, three‐component seismic network deployed around the Coso, California, geothermal reservoir since 1992 display distinctive shear‐wave splitting and clear polarization directions. From the polarizations we estimated three predominant subsurface fracture directions, and from the time delays of the split waves we determined tomographically the 3-D fracture density distribution in the reservoir.

Reconnaissance geophysical studies of the geothermal system in southern Raft River Valley, Idaho

Geophysics ◽  
1978 ◽  
Vol 43 (7) ◽  
pp. 1470-1484 ◽  
Author(s):  
Don R. Mabey ◽  
Donald B. Hoover ◽  
James E. O’Donnell ◽  
Carol W. Wilson
Keyword(s):  
Salt Lake ◽  
Gravity Data ◽  
River Valley ◽  
Geothermal Reservoir ◽  
Normal Faults ◽  
Geothermal System ◽  
Surface Hydrology ◽  
Near Surface ◽  
Circulating Water ◽  
Lake Formation

Gravity, aeromagnetic, and telluric current surveys in the southern Raft River have been used to infer the structure and the general lithology underlying the valley. The gravity data indicate the approximate thickness of the Cenozoic rocks and location of the larger normal faults, and the aeromagnetic data indicate the extent of the major Cenozoic volcanic units. The relative ellipse area contour map compiled from the telluric current survey generally conforms to the gravity map except for lower values in the area of the geothermal system. An area of low apparent resistivity values defined by the audiomagnetotelluric (AMT) survey appears to outline the extent of the geothermal reservoir even though the reservoir is deeper than the penetration of the survey. Self‐potential anomalies relate to near surface hydrology. The Raft River Valley is underlain by about 2 km of Cenozoic rock, most of which is Tertiary sediments of the Salt Lake formation. On the west side of the valley the Tertiary rocks appear to be separated from the underlying Precambrian basement by a low angle fault along which the Tertiary rocks have slid off a buried basement dome. Subsequent normal faults displace both the basement surface and the Tertiary beds. The geothermal system occurs where these north‐trending faults intersect a poorly understood northeast‐trending zone that may be a basement shear zone. Apparently deep circulating water at a temperature of about 150°C rises in the area of this intersection and then spreads laterally in porous zones near the base of the Tertiary rocks to form the geothermal reservoir. Upward leakage from the reservoir produces shallower effects that were measured by the AMT survey.

Benthic foraminiferal zonation in deep-water carbonate platform margin environments, northern Little Bahama Bank

1988 ◽  
Vol 62 (01) ◽  
pp. 1-8 ◽  
Author(s):  
Ronald E. Martin
Keyword(s):  
Deep Water ◽  
Benthic Foraminifera ◽  
Carbonate Platform ◽  
Sedimentary Facies ◽  
Depositional Environments ◽  
Near Surface ◽  
Sediment Gravity Flows ◽  
Gravity Flows ◽  
Platform Margin ◽  
Water Carbonate

The utility of benthic foraminifera in bathymetric interpretation of clastic depositional environments is well established. In contrast, bathymetric distribution of benthic foraminifera in deep-water carbonate environments has been largely neglected. Approximately 260 species and morphotypes of benthic foraminifera were identified from 12 piston core tops and grab samples collected along two traverses 25 km apart across the northern windward margin of Little Bahama Bank at depths of 275-1,135 m. Certain species and operational taxonomic groups of benthic foraminifera correspond to major near-surface sedimentary facies of the windward margin of Little Bahama Bank and serve as reliable depth indicators. Globocassidulina subglobosa, Cibicides rugosus, and Cibicides wuellerstorfi are all reliable depth indicators, being most abundant at depths >1,000 m, and are found in lower slope periplatform aprons, which are primarily comprised of sediment gravity flows. Reef-dwelling peneroplids and soritids (suborder Miliolina) and rotaliines (suborder Rotaliina) are most abundant at depths <300 m, reflecting downslope bottom transport in proximity to bank-margin reefs. Small miliolines, rosalinids, and discorbids are abundant in periplatform ooze at depths <300 m and are winnowed from the carbonate platform. Increased variation in assemblage diversity below 900 m reflects mixing of shallow- and deep-water species by sediment gravity flows.

Analysis of 2D and 3D defects associated with precipitation of Cu in silicon

1991 ◽  
Vol 49 ◽  
pp. 870-871
Author(s):  
P.M. Rice ◽  
MJ. Kim ◽  
R.W. Carpenter
Keyword(s):  
Colony Growth ◽  
Dark Field ◽  
Dark Side ◽  
Silicide Phase ◽  
Strain Fields ◽  
Near Surface ◽  
Unknown Composition ◽  
Secondary Precipitates ◽  
20 Nm ◽  
2D And 3D

Extrinsic gettering of Cu on near-surface dislocations in Si has been the topic of recent investigation. It was shown that the Cu precipitated hetergeneously on dislocations as Cu silicide along with voids, and also with a secondary planar precipitate of unknown composition. Here we report the results of investigations of the sense of the strain fields about the large (~100 nm) silicide precipitates, and further analysis of the small (~10-20 nm) planar precipitates.Numerous dark field images were analyzed in accordance with Ashby and Brown's criteria for determining the sense of the strain fields about precipitates. While the situation is complicated by the presence of dislocations and secondary precipitates, micrographs like those shown in Fig. 1(a) and 1(b) tend to show anomalously wide strain fields with the dark side on the side of negative g, indicating the strain fields about the silicide precipitates are vacancy in nature. This is in conflict with information reported on the η'' phase (the Cu silicide phase presumed to precipitate within the bulk) whose interstitial strain field is considered responsible for the interstitial Si atoms which cause the bounding dislocation to expand during star colony growth.

Shock consolidation of Ni-Ti alloy powder

1986 ◽  
Vol 44 ◽  
pp. 430-431
Author(s):  
Naresh N. Thadhani ◽  
Thad Vreeland ◽  
Thomas J. Ahrens
Keyword(s):  
Alloy Powder ◽  
Amorphous Material ◽  
Ti Alloy ◽  
Two Phase ◽  
Near Surface ◽  
Optical Micrograph ◽  
Shock Compaction ◽  
Powder Particles ◽  
Ti Powder ◽  
Rapidly Solidified

A spherically-shaped, microcrystalline Ni-Ti alloy powder having fairly nonhomogeneous particle size distribution and chemical composition was consolidated with shock input energy of 316 kJ/kg. In the process of consolidation, shock energy is preferentially input at particle surfaces, resulting in melting of near-surface material and interparticle welding. The Ni-Ti powder particles were 2-60 μm in diameter (Fig. 1). About 30-40% of the powder particles were Ni-65wt% and balance were Ni-45wt%Ti (estimated by EMPA).Upon shock compaction, the two phase Ni-Ti powder particles were bonded together by the interparticle melt which rapidly solidified, usually to amorphous material. Fig. 2 is an optical micrograph (in plane of shock) of the consolidated Ni-Ti alloy powder, showing the particles with different etching contrast.

Preparation of cross-sectional samples for near-surface TEM studies

1987 ◽  
Vol 45 ◽  
pp. 380-381
Author(s):  
R.C. Dickenson ◽  
K.R. Lawless
Keyword(s):  
Standard Sample ◽  
Surface Region ◽  
Specimen Preparation ◽  
Thick Sheet ◽  
Drill Bit ◽  
Sample Holder ◽  
Metal Interface ◽  
Cross Sectional ◽  
Near Surface ◽  
Cold Worked

In thermal oxidation studies, the structure of the oxide-metal interface and the near-surface region is of great importance. A technique has been developed for constructing cross-sectional samples of oxidized aluminum alloys, which reveal these regions. The specimen preparation procedure is as follows: An ultra-sonic drill is used to cut a 3mm diameter disc from a 1.0mm thick sheet of the material. The disc is mounted on a brass block with low-melting wax, and a 1.0mm hole is drilled in the disc using a #60 drill bit. The drill is positioned so that the edge of the hole is tangent to the center of the disc (Fig. 1) . The disc is removed from the mount and cleaned with acetone to remove any traces of wax. To remove the cold-worked layer from the surface of the hole, the disc is placed in a standard sample holder for a Tenupol electropolisher so that the hole is in the center of the area to be polished.

Near-Surface Aggregation of Sn In Heavily Sn-Doped GaAs Films Grown By Molecular Beam Epitaxy

1985 ◽  
Vol 43 ◽  
pp. 368-369
Author(s):  
S. H. Chen
Keyword(s):  
Molecular Beam Epitaxy ◽  
Cross Section ◽  
Electron Spectroscopy ◽  
Molecular Beam ◽  
Surface Segregation ◽  
Secondary Ion Mass Spectrometry ◽  
Specimen Preparation ◽  
Near Surface ◽  
Gaas Films ◽  
Secondary Ion

Sn has been used extensively as an n-type dopant in GaAs grown by molecular-beam epitaxy (MBE). The surface accumulation of Sn during the growth of Sn-doped GaAs has been observed by several investigators. It is still not clear whether the accumulation of Sn is a kinetically hindered process, as proposed first by Wood and Joyce, or surface segregation due to thermodynamic factors. The proposed donor-incorporation mechanisms were based on experimental results from such techniques as secondary ion mass spectrometry, Auger electron spectroscopy, and C-V measurements. In the present study, electron microscopy was used in combination with cross-section specimen preparation. The information on the morphology and microstructure of the surface accumulation can be obtained in a fine scale and may confirm several suggestions from indirect experimental evidence in the previous studies.

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