Shallow VSP work in the U.S. Appalachian coal basin

Geophysics ◽  
1998 ◽  
Vol 63 (3) ◽  
pp. 795-799
Author(s):  
Lawrence M. Gochioco
Keyword(s):  
Seismic Reflection ◽  
Reflection Method ◽  
Coal Seams ◽  
Seismic Section ◽  
Additional Information ◽  
Seismic Wavelet ◽  
Common Depth Point ◽  
Seismic Reflection Method ◽  
Weathered Layer ◽  
Sonic Logs

Most geophysical applications in North American coal exploration have centered around the conventional surface seismic reflection method to provide continuous subsurface coverage for evaluating both good and anomalous coal reserve areas (Ruskey, 1981; Dobecki and Bartel, 1982; Greaves, 1984; Lawton, 1985; Lyatsky and Lawton, 1988; Gochioco and Cotten, 1989; Lawton and Lyatsky, 1989; Gochioco and Kelly, 1990; Gochioco, 1991; Henson and Sexton, 1991). The surface seismic reflection method, however, has inherent resolution limitations because the seismic wavelet must propagate substantial distances through the weathered layer, resulting in rapid attenuation of the desired higher frequencies. Since the depths and thicknesses of coal seams are usually known before‐hand, it is imperative that the seismic reflection associated with the target coal seam is absolutely identified in the seismic section to avoid misinterpretations. However, it is common that checkshot data and sonic and density logs are not available to generate synthetic seismograms to assist in the interpretation of coal seismic data. To overcome some of these limitations, the vertical seismic profiling (VSP) technique was tested in a coal exploration program to provide additional information for correlation with surface seismic reflection [or common‐depth‐point (CDP)] data and a synthetic seismogram generated from density and sonic logs.

scholarly journals Shallow seismic reflection survey for imaging deep-seated coal layer - Case study from Muara Enim coal

2021 ◽  
Vol 24 (1) ◽  
pp. 15-29
Author(s):  
Muhammad Ramdhani ◽  
◽  
Muhammad Ibrahim ◽  
Hans Siregar ◽  
Tony Rahadinata ◽  
...  
Keyword(s):  
Seismic Reflection ◽  
Coalbed Methane ◽  
Coal Gasification ◽  
Reflection Method ◽  
Borehole Data ◽  
Seismic Section ◽  
Shallow Seismic ◽  
Coal Layer ◽  
Seismic Reflection Method ◽  
Amplitude Characteristics

Indonesia has a great potential for deep-seated coal resources. To assist and support the deep-seated coal exploration, a shallow seismic reflection method is applicable for this purpose. This study has conducted a shallow seismic reflection method in Musi Banyuasin Regency, South Sumatera Province. The Muara Enim coal target varies from 100 to 500 meters from the surface. The thickness of the coal layer varies from 2 to 10.65 meters. This study uses 48 channels with 14 Hz single geophone and MiniSosie as the energy source. The receiver and source interval is 15 meters. This study uses a fixed receiver and moving source configuration. From the interpreted seismic section, this study identified a deep-seated coal layer target. These layers are Mangus, Burung, Benuang, Kebon and Benakat layers. A simple interpretation is analyzed by combining the seismic amplitude characteristics and the thickness of the coal layer from the borehole data. From the interpreted seismic section, deep-seated coal layer targets have strong amplitude characteristics and are continuous from southwest to the northeast with a down-dip of around 20-30°. This study helps to inform the operator companies who develop the utilization of deep-seated coal (coalbed methane, underground coal gasification and underground coal mining) about the effective and proper geophysical method for imaging deep-seated coal layer.

Using Areal Common Depth-Point (CMP) Seismic Reflection Method for Additional Exploration of the Coal Field

2020 ◽  
Author(s):  
A.M. Turchkov ◽  
A.N Oshkin ◽  
I.P. Korotkov ◽  
E.A. Keldyushova ◽  
A.A. Vyaznikovcev
Keyword(s):  
Seismic Reflection ◽  
Reflection Method ◽  
Coal Field ◽  
Common Depth Point ◽  
Seismic Reflection Method

Feasibility of CDP seismic reflection to image structures in a 220-m deep, 3-m thick coal zone near Palau, Coahuila, Mexico

Geophysics ◽  
1992 ◽  
Vol 57 (10) ◽  
pp. 1373-1380 ◽  
Author(s):  
Richard D. Miller ◽  
Victor Saenz ◽  
Robert J. Huggins
Keyword(s):  
Seismic Data ◽  
Seismic Reflection ◽  
Subsurface Structure ◽  
Reflection Method ◽  
Accurate Identification ◽  
Common Depth Point ◽  
Seismic Reflection Method ◽  
The Common ◽  
Zone Depth ◽  
Seismic Sections

The common‐depth‐point (CDP) seismic‐reflection method was used to delineate subsurface structure in a 3-m thick, 220-m deep coal zone in the Palau area of Coahuila, Mexico. An extensive series of walkaway‐noise tests was performed to optimize recording parameters and equipment. Reflection events can be interpreted from depths of approximately 100 to 300 m on CDP stacked seismic sections. The seismic data allow accurate identification of the horizontal location of the structure responsible for a drill‐discovered 3-m difference in coal‐zone depth between boreholes 150 m apart. The reflection method can discriminate folding with wavelengths in excess of 20 m and faulting with offset greater than 2 m at this site.

Detecting Abandoned Air-Raid Shelter Using The S-Wave Seismic Reflection Method

2008 ◽  
Author(s):  
Shunichiro Ito ◽  
Takao Aizawa ◽  
Fumio Nakada ◽  
Ryosuke Kitamura
Keyword(s):  
Seismic Reflection ◽  
Reflection Method ◽  
S Wave ◽  
Seismic Reflection Method

Seismic Reflection Expression of Reactivated Structures in the New Madrid Rift Complex

1988 ◽  
Vol 59 (4) ◽  
pp. 141-150 ◽  
Author(s):  
John. L. Sexton
Keyword(s):  
Seismic Reflection ◽  
Structural Features ◽  
Normal Faults ◽  
Earthquake Activity ◽  
Seismic Zone ◽  
Reflection Method ◽  
Intraplate Earthquakes ◽  
Reflection Data ◽  
Seismic Reflection Method ◽  
New Madrid

Abstract An important aspect of seismogenesis concerns the role of preexisting faults and other structural features as preferred zones of weakness in determining the pattern of strain accumulation and seismicity. Reactivation of zones of weakness by present day stress fields may be the cause of many intraplate earthquakes. To understand the relation between reactivated structures and seismicity, it is necessary to identify structures which are properly oriented with respect to the present-day stress field so that reactivation can occur. The seismic reflection method is very useful for identifying and delineating structures, particularly in areas where the structures are buried as in the New Madrid seismic zone. Application of the seismic reflection method in widely separated locations within the New Madrid rift complex has resulted in successful detection and delineation of reactivated rift-related structures which are believed to be associated with earthquake activity. The purpose of this paper is to discuss results from seismic reflection profiling in the New Madrid rift complex. Reflection data from several surveys including USGS Vibroseis* surveys in the Reelfoot rift area reveal reactivated faults and other deep rift-related structures which appear to be associated with seismicity. High-resolution explosive and Mini-Sosie** reflection surveys on Reelfoot scarp and through the town of Cottonwood Grove, Tennessee, clearly show reverse faults in Paleozoic and younger rocks which have been reactivated to offset younger rocks. A Vibroseis survey in the Wabash Valley area of the New Madrid rift complex provides direct evidence for a few hundred feet of post-Pennsylvanian age reactivation of large-offset normal faults in Precambrian-age basement rocks. Several earthquake epicenters have been located in the vicinity of these structures. In the Rough Creek graben, Vibroseis reflection data provide clear evidence for reactivation of basement faults. The success of these reflection surveys shows that well-planned seismic reflection surveys must be included in any program seeking to determine the relationship between preexisting zones of weakness and seismicity of an area.

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