Development of 3-D seismic exploration technology for deep nickel‐copper deposits—A case history from the Sudbury basin, Canada

Geophysics ◽  
2000 ◽  
Vol 65 (6) ◽  
pp. 1890-1899 ◽  
Author(s):  
Bernd Milkereit ◽  
E. K. Berrer ◽  
Alan R. King ◽  
Anthony H. Watts ◽  
B. Roberts ◽  
...  
Keyword(s):  
Direct Detection ◽  
Mineral Exploration ◽  
Massive Sulfide ◽  
Seismic Survey ◽  
Seismic Exploration ◽  
Seismic Scattering ◽  
Sudbury Igneous Complex ◽  
Seismic Methods ◽  
Seismic Experiment ◽  
Nickel Copper

Following extensive petrophysical studies and presite surveys, the Trill area of the Sudbury basin was selected for conducting the first 3-D seismic survey for mineral exploration in North America. The 3-D seismic experiment confirms that in a geological setting such as the Sudbury Igneous Complex, massive sulfide bodies cause a characteristic seismic scattering response. This provides an excellent basis for the direct detection of massive sulfides by seismic methods. The feasibility study suggests that high‐resolution seismic methods offer a large detection radius in the order of hundreds to thousands of meters, together with accurate depth estimates.

Performance of low-fold scalar migration for downhole seismic imaging of massive sulfide ore deposits at Norman West, Sudbury, Canada

Geophysics ◽  
2012 ◽  
Vol 77 (5) ◽  
pp. WC3-WC13 ◽  
Author(s):  
Christof Mueller ◽  
Gilles Bellefleur ◽  
Erick Adam ◽  
Gervais Perron ◽  
Marko Mah ◽  
...  
Keyword(s):  
Seismic Data ◽  
Seismic Imaging ◽  
Signal To Noise Ratio ◽  
Massive Sulfide ◽  
Ore Deposits ◽  
Ore Deposit ◽  
Seismic Scattering ◽  
Vertical Seismic Profiling ◽  
Sudbury Igneous Complex ◽  
Sulfide Ore

The Downhole Seismic Imaging consortium conducted two consecutive vertical seismic profiling surveys in the Norman West mining camp (Sudbury, Canada) in 1998 and 1999. These were aimed toward imaging a massive sulfide ore deposit situated within the footwall of the Sudbury Igneous Complex (SIC). Three-component seismic data were acquired in four boreholes with variable signal-to-noise ratio and poor polarization quality. Consequently, the images suffered from strong azimuthal ambiguity. A strike filter, passing only reflections originating from within the SIC, was applied during migration to enhance interpretability of the images obtained. Migrated images showed structures correlating with the known position of an ore deposit located 1800 m away from one borehole (N40). Diffraction coherency migration enhanced the image of the deposit, and suggested strong seismic scattering from within the footwall of the SIC.

Innovative seismic imaging of volcanogenic massive sulfide deposits, Neves-Corvo, Portugal — Part 2: Surface array

Geophysics ◽  
2021 ◽  
Vol 86 (3) ◽  
pp. B181-B191 ◽  
Author(s):  
George A. Donoso ◽  
Alireza Malehmir ◽  
Bojan Brodic ◽  
Nelson Pacheco ◽  
João Carvalho ◽  
...  
Keyword(s):  
New Technologies ◽  
Mineral Exploration ◽  
Velocity Model ◽  
Massive Sulfide ◽  
Seismic Survey ◽  
Prototype System ◽  
Mining Operations ◽  
Seismic Section ◽  
Surface Data ◽  
Surface Profiles

Seismic methods are an affordable and effective way of studying the subsurface for mineral exploration. With the goal of testing new technologies for mineral exploration in highly challenging mining areas, in early 2019, an innovative seismic survey was conducted at the Neves-Corvo mine, south Portugal. We have focused on the data and results from the surface array data, whereas other work deals with the underground seismic data. The surface seismic survey consisted of two perpendicular 2D profiles positioned above the known world-class tier-1 Lombador deposit. Simultaneously, a survey inside the active underground mine took place, being unique because it included the testing of a prototype system that enabled accurate GPS-time (microsecond accuracy) synchronization inside the mine tunnels, approximately 650 m below the surface profiles. Due to the active mining operations, the surface data are noisy. To handle this, a carefully tailored processing algorithm was developed and applied to enhance reflections in the data, interpreted to originate from lithologic contacts and the Lombador deposit. The results and interpretations from 2D processing were validated taking advantage of the known deposit geometry using 3D exploding reflector modeling and pseudo-3D cross-dip analysis. These analyses suggest that there is an out-of-plane signature of the Lombador deposit on the surface data. Additionally, source points activated in the exploration tunnels and simultaneously recorded on the surface profiles allowed for the creation of a 2D velocity model that was used for migration and time-to-depth conversion, providing a reliable 2D seismic section of the subsurface under the surface profiles. We determine that limited surface coverage 2D surveys and a velocity model derived from the tunnel-to-surface seismic recordings allow for imaging of key subsurface geologic structures and delineating mineral deposits of economic interest.

scholarly journals Cost-Effective Seismic Exploration: 2D Reflection Imaging at the Kylylahti Massive Sulfide Deposit, Finland

Minerals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 263 ◽  
Author(s):  
Suvi Heinonen ◽  
Michal Malinowski ◽  
Felix Hloušek ◽  
Gardar Gislason ◽  
Stefan Buske ◽  
...  
Keyword(s):  
Seismic Data ◽  
Seismic Reflection ◽  
Imaging Techniques ◽  
Mineral Exploration ◽  
Massive Sulfide ◽  
Seismic Profile ◽  
Seismic Exploration ◽  
Sulfide Deposit ◽  
Depth Imaging ◽  
Seismic Reflection Profiles

We show that by using an advanced pre-stack depth imaging algorithm it is possible to retrieve meaningful and robust seismic images with sparse shot points, using only 3–4 source points per kilometer along a seismic profile. Our results encourage the use of 2D seismic reflection profiling as a reconnaissance tool for mineral exploration in areas with limited access for active seismic surveys. We used the seismic data acquired within the COGITO-MIN project comprising two approximately 6 km long seismic reflection profiles at the polymetallic Kylylahti massive sulfide mine site in eastern Finland. The 2D seismic data acquisition utilized both Vibroseis and dynamite sources with 20 m spacing and wireless receivers spaced every 10 m. For both source types, the recorded data show clear first breaks over all offsets and reflectors in the raw shot gathers. The Kylylahti area is characterized by folded and faulted, steeply dipping geological contacts and structures. We discuss post-stack and pre-stack data processing and compare time and depth imaging techniques in this geologically complex Precambrian hardrock area. The seismic reflection profiles show prominent reflectors at 4.5–8 km depth utilizing different migration routines. In the shallow subsurface, steep reflectors are imaged, and within and underneath the known Kylylahti ultramafic body reflectivity is prominent but discontinuous.

scholarly journals Analysis of Seismic Methods Used for Subsea Hydrocarbon Exploration

2020 ◽  
Vol 58 (1) ◽  
pp. 77-89
Author(s):  
Ivan Birin ◽  
Lovro Maglić
Keyword(s):  
Seismic Waves ◽  
Seismic Station ◽  
Hydrocarbon Exploration ◽  
Seismic Survey ◽  
Seismic Exploration ◽  
Seismic Arrays ◽  
Seismic Methods ◽  
Subsurface Layers ◽  
Hydrocarbon Fields ◽  
Marine Seismic

Subsea hydrocarbon exploration comprises detection and estimation of shape, depth, volume and other physical properties of hydrocarbon fields within the Earth’s subsurface layers. Marine seismic survey is a process that generally includes sending seismic waves into seabed and recording the intensity and travel time of reflected seismic waves to determine the subsurface features of the Earth. Different methods, equipment and techniques are used to conduct a survey, from sea surface seismic arrays to seabed local seismic station networks. In this paper different widely used seismic methods are presented, together with their advantages and drawbacks. Furthermore, new methods that are being developed and tested for future approach to more advanced and efficient seismic exploration are presented.

scholarly journals S-wave experiments for the exploration of a deep geothermal carbonate reservoir in the German Molasse Basin

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Britta Wawerzinek ◽  
Hermann Buness ◽  
Hartwig von Hartmann ◽  
David C. Tanner
Keyword(s):  
Upper Jurassic ◽  
Carbonate Reservoir ◽  
P Wave ◽  
Seismic Survey ◽  
Seismic Exploration ◽  
Molasse Basin ◽  
S Wave ◽  
Induced Earthquakes ◽  
Conversion Point ◽  
Facies Classification

AbstractThere are many successful geothermal projects that exploit the Upper Jurassic aquifer at 2–3 km depth in the German Molasse Basin. However, up to now, only P-wave seismic exploration has been carried out. In an experiment in the Greater Munich area, we recorded S-waves that were generated by the conventional P-wave seismic survey, using 3C receivers. From this, we built a 3D volume of P- to S-converted (PS) waves using the asymptotic conversion point approach. By combining the P-volume and the resulting PS-seismic volume, we were able to derive the spatial distribution of the vp/vs ratio of both the Molasse overburden and the Upper Jurassic reservoir. We found that the vp/vs ratios for the Molasse units range from 2.0 to 2.3 with a median of 2.15, which is much higher than previously assumed. This raises the depth of hypocenters of induced earthquakes in surrounding geothermal wells. The vp/vs ratios found in the Upper Jurassic vary laterally between 1.5 and 2.2. Since no boreholes are available for verification, we test our results against an independently derived facies classification of the conventional 3D seismic volume and found it correlates well. Furthermore, we see that low vp/vs ratios correlate with high vp and vs velocities. We interpret the latter as dolomitized rocks, which are connected with enhanced permeability in the reservoir. We conclude that 3C registration of conventional P-wave surveys is worthwhile.

Seismic solutions utilizing existing in-mine infrastructure for mineral exploration: A case study from Maseve platinum mine, South Africa

2022 ◽  
Vol 41 (1) ◽  
pp. 54-61
Author(s):  
Moyagabo K. Rapetsoa ◽  
Musa S. D. Manzi ◽  
Mpofana Sihoyiya ◽  
Michael Westgate ◽  
Phumlani Kubeka ◽  
...  
Keyword(s):  
South Africa ◽  
Seismic Data ◽  
Mineral Exploration ◽  
Ground Surface ◽  
Seismic Survey ◽  
Noisy Environment ◽  
Borehole Data ◽  
Passive Seismic ◽  
Below Ground

We demonstrate the application of seismic methods using in-mine infrastructure such as exploration tunnels to image platinum deposits and geologic structures using different acquisition configurations. In 2020, seismic experiments were conducted underground at the Maseve platinum mine in the Bushveld Complex of South Africa. These seismic experiments were part of the Advanced Orebody Knowledge project titled “Developing technologies that will be used to obtain information ahead of the mine face.” In these experiments, we recorded active and passive seismic data using surface nodal arrays and an in-mine seismic land streamer. We focus on analyzing only the in-mine active seismic portion of the survey. The tunnel seismic survey consisted of seven 2D profiles in exploration tunnels, located approximately 550 m below ground surface and a few meters above known platinum deposits. A careful data-processing approach was adopted to enhance high-quality reflections and suppress infrastructure-generated noise. Despite challenges presented by the in-mine noisy environment, we successfully imaged the platinum deposits with the aid of borehole data and geologic models. The results open opportunities to adapt surface-based geophysical instruments to address challenging in-mine environments for mineral exploration.

Pb-Nd-Sr Isotope Geochemistry of Metapelites from the Iberian Pyrite Belt and Its Relevance to Provenance Analysis and Mineral Exploration Surveys

2021 ◽  
Author(s):  
Filipa Luz ◽  
António Mateus ◽  
Ezequiel Ferreira ◽  
Colombo G. Tassinari ◽  
Jorge Figueiras
Keyword(s):  
Isotope Geochemistry ◽  
Mineral Exploration ◽  
Hanging Wall ◽  
Massive Sulfide ◽  
Iberian Pyrite Belt ◽  
Isotopic Signature ◽  
Sr Isotope ◽  
Provenance Analysis ◽  
Basement Rocks ◽  
World Class

Abstract The boundary in the Iberian Pyrite Belt is a world-class metallogenic district developed at the Devonian-Carboniferous boundary the Iberian Variscides that currently has seven active mines: Neves Corvo (Cu-Zn-Sn) and Aljustrel (Cu-Zn) in Portugal, and Riotinto (Cu), Las Cruces (Cu), Aguas Teñidas (Cu-Zn-Pb), Sotiel-Coronada (Cu-Zn-Pb), and La Magdalena (Cu-Zn-Pb) in Spain. The Iberian Pyrite Belt massive sulfide ores are usually hosted in the lower sections of the volcano-sedimentary complex (late Famennian to late Visean), but they also occur in the uppermost levels of the phyllite-quartzite group at the Neves Corvo deposit, stratigraphically below the volcano-sedimentary complex. A Pb-Nd-Sr isotope dataset was obtained for 98 Iberian Pyrite Belt metapelite samples (from Givetian to upper Visean), representing several phyllite-quartzite group and volcano-sedimentary complex sections that include the footwall and hanging-wall domains of ore horizons at the Neves Corvo, Aljustrel, and Lousal mines. The combination of whole-rock Nd and Sr isotopes with Th/Sc ratios shows that the siliciclastic components of Iberian Pyrite Belt metapelites are derived from older quartz-feldspathic basement rocks (–11 ≤ εNdinitial(i) ≤ –8 and (87Sr/86Sr)i up to 0.727). The younger volcano-sedimentary complex metapelites (upper Tournaisian) often comprise volcanic-derived constituents with a juvenile isotopic signature, shifting the εNdi up to +0.2. The Pb isotope data confirm that the phyllite-quartzite group and volcano-sedimentary complex successions are crustal reservoirs for metals found in the deposits. In Neves Corvo, where there is more significant Sn- and Cu-rich mineralization, the higher (206Pb/204Pb)i and (207Pb/204Pb)i values displayed by phyllite-quartzite group and lower volcano-sedimentary complex metapelites (up to 15.66 and 18.33, respectively) suggest additional contributions to the metal budget from a deeper and more radiogenic source. The proximity to Iberian Pyrite Belt massive sulfide ore systems hosted in metapelite successions is observed when (207Pb/204Pb)i >15.60 and Fe2O3/TiO2 or (Cu+Zn+Pb)/Sc >10. These are important criteria that should be considered in geochemical exploration surveys designed for the Iberian Pyrite Belt.

scholarly journals Seismic Methods in Geothermal Water Resource Exploration: Case Study from Łódź Trough, Central Part of Poland

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Tomasz Maćkowski ◽  
Anna Sowiżdżał ◽  
Anna Wachowicz-Pyzik
Keyword(s):  
Estimation Error ◽  
Geophysical Methods ◽  
Petroleum Industry ◽  
Geological Structure ◽  
Seismic Survey ◽  
Energy Potential ◽  
Geothermal Resources ◽  
Geothermal Waters ◽  
Seismic Methods ◽  
Geophysical Surveys

The geothermal waters constitute a specific type of water resources, very important from the point of view of their thermal energy potential. This potential, when utilized, supplies an ecological and renewable energy, which, after effective development, brings many environmental, social, and industrial benefits. The key element of any geothermal investment is the proper location of geothermal installation, which would guarantee the relevant hydrogeothermal parameters of the water intake. Hence, many studies and analyses are carried out in order to characterize the reservoir parameters, including the integrated geophysical methods. For decades, the geophysical surveys have been the trusty recognition methods of geological structure and petrophysical parameters of rock formations. Thus, they are widely applied by petroleum industry in exploration of conventional and unconventional (shale gas/oil, tight gas) hydrocarbon deposits. Advances in geophysical methods extended their applicability to many other scientific and industrial branches as, e.g., the seismic survey used in studies of geothermal aquifers. The following paper presents the opportunities provided by seismic methods applied to studies of geothermal resources in the central Poland where the geothermal waters are reservoired in both the Lower Cretaceous and the Lower Jurassic sedimentary successions. The presented results are obtained from a network of seismic profiles. An important advantage of the seismic survey is that they may support the selection of an optimal location of geothermal investment and determination of the geometry of geothermal aquifer. Furthermore, the application of geophysical methods can significantly contribute to the reduction of estimation error of groundwater reservoir temperature.

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