Geophysical and analytical determination of overstressed zones in exploited coal seam: a case study

Acta Geophysica ◽

10.1007/s11600-021-00547-z ◽

2021 ◽

Author(s):

Dariusz Chlebowski ◽

Zbigniew Burtan

Keyword(s):

Coal Seam ◽

Wave Velocity ◽

Seismic Tomography ◽

Analytical Modeling ◽

Coal Mines ◽

Vertical Stress ◽

P Wave ◽

Rockburst Hazard ◽

State Of Stress ◽

P Wave Velocity

AbstractA variety of geophysical methods and analytical modeling are applied to determine the rockburst hazard in Polish coal mines. In particularly unfavorable local conditions, seismic profiling, active/passive seismic tomography, as well as analytical state of stress calculating methods are recommended. They are helpful in verifying the reliability of rockburst hazard forecasts. In the article, the combined analysis of the state of stress determined by active seismic tomography and analytical modeling was conducted taking into account the relationship between the location of stress concentration zones and the level of rockburst hazard. A longwall panel in the coal seam 501 at a depth of ca.700 m in one of the hard coal mines operating in the Upper Silesian Coal Basin was a subject of the analysis. The seismic tomography was applied for the reconstruction of P-wave velocity fields. The analytical modeling was used to calculate the vertical stress states basing on classical solutions offered by rock mechanics. The variability of the P-wave velocity field and location of seismic anomaly in the coal seam in relation to the calculated vertical stress field arising in the mined coal seam served to assess of rockburst hazard. The applied methods partially proved their adequacy in practical applications, providing valuable information on the design and performance of mining operations.

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The P-wave velocity structure of Deception Island, Antarctica, from two-dimensional seismic tomography

Journal of Volcanology and Geothermal Research ◽

10.1016/j.jvolgeores.2008.11.020 ◽

2009 ◽

Vol 180 (1) ◽

pp. 67-80 ◽

Cited By ~ 20

Author(s):

Tami Ben-Zvi ◽

William S.D. Wilcock ◽

Andrew H. Barclay ◽

Daria Zandomeneghi ◽

Jesús M. Ibáñez ◽

...

Keyword(s):

Wave Velocity ◽

Seismic Tomography ◽

Velocity Structure ◽

P Wave ◽

Two Dimensional ◽

Deception Island ◽

P Wave Velocity ◽

P Wave Velocity Structure

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Analisis Model Kecepatan Gelombang-P pada Coal-Seam Gas Studi Kasus Cekungan Sumatera Selatan, Indonesia

Jurnal Geofisika Eksplorasi ◽

10.23960/jge.v6i2.74 ◽

2020 ◽

Vol 6 (2) ◽

pp. 113-120

Author(s):

Harnanti Yogaputri Hutami ◽

Fitriyani Fitriyani ◽

Tiara Larasati Priniarti ◽

Handoyo Handoyo

Keyword(s):

Coal Seam ◽

Elastic Properties ◽

Wave Velocity ◽

Rock Physics ◽

Velocity Model ◽

Significant Negative Correlation ◽

P Wave ◽

Gas Content ◽

Coal Seam Gas ◽

P Wave Velocity

The rock physics model is one effective yet challenging way to investigate the coal-seam gas potential in Indonesia. However, because of the complex conditions of the Coal-Seam Gas Reservoirs, it is difficult to establish models. Despite the scarce modeling, this study aims to estimate the relation of gas-saturated within pores of coal seam to the elastic properties of rock, which is P-wave velocity. First, the coal seam minerals are applied to quantify matrix moduli using the Voigt-Reuss-Hill Average method. Pride’s simple equation is used to estimate the elastic properties of the coal seam at dry condition (zero gas saturation). Finally, Biot-Gassmann’s theory is applied to determine the elastic properties of coal seam with fully gas saturated. As the result, the proposed model showed that there is a significant negative correlation between gas content with both density and P-wave velocity of the coal seam. Finally, this P-wave velocity model of gas-saturated coal seams should be properly useful as the quick look for identifying coal seam gas potentials.

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Three-Dimensional P-wave Velocity Structure of the Zhuxi Ore Deposit, South China Revealed by Control-Source First-Arrival Tomography

Minerals ◽

10.3390/min10020148 ◽

2020 ◽

Vol 10 (2) ◽

pp. 148

Author(s):

Yunpeng Zhang ◽

Baoshan Wang ◽

Guoqing Lin ◽

Yongpeng Ouyang ◽

Tao Wang ◽

...

Keyword(s):

Wave Velocity ◽

Seismic Tomography ◽

Velocity Structure ◽

Three Dimensional ◽

P Wave ◽

Ore Deposit ◽

P Wave Velocity ◽

Velocity Anomalies ◽

P Wave Velocity Structure ◽

Control Source

The Zhuxi ore deposit, located in Jiangxi province, South China, is the largest tungsten reserve in the world. To better understand the geological structure and distribution of orebodies, we conducted a high resolution three-dimensional P-wave velocity tomography of the uppermost 0.5 km beneath the Zhuxi ore deposit and adjacent area. Our velocity model was derived from 761,653 P-wave first arrivals from 998 control-source shots, recorded by a dense array. As the first 3D P-wave velocity structure of the Zhuxi ore deposit, our model agrees with local topographic and tectonic structures and shows depth-dependent velocity similar to laboratory measurements. The Carboniferous formations hosting the proven orebodies are imaged as high velocities. The high-velocity anomalies extend to a larger area beyond the proven orebodies, and the locations of high–low velocity boundaries are in accordance with the boundaries between the Neoproterozoic formation and the Carboniferous–Triassic formation. Seismic tomography reveals that high-velocity anomalies are closely related to the mineralized areas. Our results are helpful for further evaluating the total reserves and suggest that seismic tomography can be a useful tool for mineral exploration.

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