scholarly journals Sparse 3D Seismic Imaging in the Kylylahti Mine Area, Eastern Finland: Comparison of Time Versus Depth Approach

Minerals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 305 ◽  
Author(s):  
Brij Singh ◽  
Michał Malinowski ◽  
Felix Hloušek ◽  
Emilia Koivisto ◽  
Suvi Heinonen ◽  
...  

A 10.5 km2 3D seismic survey was acquired over the Kylylahti mine area (Outokumpu mineral district, eastern Finland) as a part of the COGITO-MIN (COst-effective Geophysical Imaging Techniques for supporting Ongoing MINeral exploration in Europe) project, which aimed at the development of cost-effective geophysical imaging methods for mineral exploration. The cost-effectiveness in our case was related to the fact that an active-source 3D seismic survey was accomplished by using the receiver spread originally designed for a 3D passive survey. The 3D array recorded Vibroseis and dynamite shots from an active-source 2D seismic survey, from a vertical seismic profiling experiment survey, as well as some additional “random” Vibroseis and dynamite shots made to complement the 3D source distribution. The resulting 3D survey was characterized by irregular shooting geometry and relatively large receiver intervals (50 m). Using this dataset, we evaluate the effectiveness of the standard time-imaging approach (post-stack and pre-stack time migration) compared to depth imaging (standard and specialized Kirchhoff pre-stack depth migration, KPreSDM). Standard time-domain processing and imaging failed to convincingly portray the first ~1500 m of the subsurface, which was the primary interest of the survey. With a standard KPreSDM, we managed to obtain a good image of the base of the Kylylahti formation bordering the extent of the mineralization-hosting Outokumpu assemblage rocks, but otherwise the image was very noisy in the shallower section. The specialized KPreSDM approach (i.e., coherency-based Fresnel volume migration) resulted in a much cleaner image of the shallow, steeply dipping events, as well as some additional deeper reflectors, possibly representing repetition of the contact between the Outokumpu assemblage and the surrounding Kalevian metasediments at depth.

1989 ◽  
Vol 20 (2) ◽  
pp. 229
Author(s):  
S.C. Stewart ◽  
B.J. Evans

As part of an industry funded research project into the application of the technique of LOFOLD3D land seismic surveying, a four fold three dimensional seismic survey was performed in the Perth Basin at Moora, Western Australia in July 1987. The volume covered an area of four kilometres by just under two kilometres, producing a total of 23,000 common midpoint traces. The objective was to collect and process the data in such a manner that a three dimensional structural interpretation would result, which would be the same as that resulting from a conventional three dimensional survey. A cost comparison indicates that a commercial LOFOLD3D survey would reduce the cost of performing a land 3D survey to an estimated 20% of the full fold equivalent, and the technique therefore offers potential for substantial savings if it is adopted on a commercial basis.


Geophysics ◽  
2007 ◽  
Vol 72 (5) ◽  
pp. A63-A67 ◽  
Author(s):  
Peter A. Crisi ◽  
Shelton E. Hubbell

Two different 3D seismic survey geometries for relatively low-fold exploration objectives are compared. The sparse geometry (S3D) is executed in swaths using a crew with 960 active channels. It is fast and cost effective, and has been used extensively in Saudi Arabia. The low fold conventional geometry (LFC3D) is acquired in blocks using a crew with about 4000 active channels. LFC3D geometries offer better geophysical attributes, with less variability of offsets and azimuths between common midpoints (CMPs), improved statics control, and higher fold with less source effort. LFC3D geometries have greater flexibility for different survey objectives than S3D geometries, and are competitive with S3D geometries in terms of cost, speed, and data quality.


2003 ◽  
Vol 43 (1) ◽  
pp. 761
Author(s):  
S.H. Mustoe ◽  
M.C. Greenwood ◽  
J.F. Moore

The Northern Fields 3D seismic survey in Bass Strait was a large survey of 4,000 km2, carried out between the months of October 2001 to July 2002. The program attracted interest from various groups regarding the possible impacts of the survey on fisheries and cetaceans (whales and dolphins).The survey was the first to operate in eastern Bass Strait after the Environment Australia Guidelines for Minimising Acoustic Disturbance to Whales, came into force, in September 2001.The Northern Fields program was conducted in accordance with a method statement for the mitigation of impacts to cetaceans, developed by Esso to meet the requirements of Australian environmental legislation and acknowledge environmental best practice. The program utilised teams of three whale watchers who maintained a continuous rotational watch of two observers throughout the day. This proved to be a reliable element of the program and was one of several key learnings that may assist other companies in developing comprehensive and cost-effective mitigation strategies for future surveys.Concerns raised by the fishing industry and some conservation groups about the potentially detrimental impact of seismic sources on commercial scallop larvae and fish populations were effectively addressed by avoiding commercial scallop areas during spawning periods. A controlled, in-situ study of scallops exposed to the acoustic source completed during the program conclusively demonstrated no significant variation in scallop mortality or muscle strength.Observation data collected during this survey provided a sample of the cetacean population in Eastern Bass Strait during a large part of the annual migration cycle. These observations, which may be relevant to the planning and execution of future seismic surveys in the region, are discussed. The findings also provide valuable information for continued research into the distribution and conservation of whales and dolphins in Bass Strait.


2022 ◽  
Vol 41 (1) ◽  
pp. 54-61
Author(s):  
Moyagabo K. Rapetsoa ◽  
Musa S. D. Manzi ◽  
Mpofana Sihoyiya ◽  
Michael Westgate ◽  
Phumlani Kubeka ◽  
...  

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.


2000 ◽  
Author(s):  
Abu Baker Al Jeelani ◽  
Samer Marmash ◽  
Abdul Salam Bin Ishaq ◽  
Ahmed Al-Shaikh ◽  
Eric Kleiss ◽  
...  

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Alireza Malehmir ◽  
Georgiana Maries ◽  
Emma Bäckström ◽  
Monika Schön ◽  
Paul Marsden

2018 ◽  
Vol 58 (2) ◽  
pp. 779
Author(s):  
Alexandra Bennett

The Patchawarra Formation is characterised by Permian aged fluvial sediments. The conventional hydrocarbon play lies within fluvial sandstones, attributed to point bar deposits and splays, that are typically overlain by floodbank deposits of shales, mudstones and coals. The nature of the deposition of these sands has resulted in the discovery of stratigraphic traps across the Western Flank of the Cooper Basin, South Australia. Various seismic techniques are being used to search for and identify these traps. High seismic reflectivity of the coals with the low reflectivity of the relatively thin sands, often below seismic resolution, masks a reservoir response. These factors, combined with complex geometry of these reservoirs, prove a difficult play to image and interpret. Standard seismic interpretation has proven challenging when attempting to map fluvial sands. Active project examples within a 196 km2 3D seismic survey detail an evolving seismic interpretation methodology, which is being used to improve the delineation of potential stratigraphic traps. This involves an integration of seismic processing, package mapping, seismic attributes and imaging techniques. The integrated seismic interpretation methodology has proven to be a successful approach in the discovery of stratigraphic and structural-stratigraphic combination traps in parts of the Cooper Basin and is being used to extend the play northwards into the 3D seismic area discussed.


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