Application of wide-field electromagnetic method in shale gas survey in Eastern Kunlun, Qinghai province, China

Besides coal seam, the source rocks including dark mudstone, carbon mudstone and so on account for a large proportion in the coal measures. Based on the complex geothermal evolution history, the majority of coal measure organic matters with the peak of gas generation have a good potential of gas. Therefore, shale gas in coal measure is an important part of the shale gas resources. There are good conditions including the thickness of coal measures, high proportion of shale rocks, rich in organic matter content, high degree of thermal evolution, high content of brittle mineral and good conditions of the porosity and permeability for the generation of shale gas in Wuli area, the south of Qinghai province. Also the direct evidence of the gas production has been obtained from the borehole. The evaluation of shale gas in coal measure resources could broaden the understanding of the shale gas resources and promote the comprehensive development of the coal resources.

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Application of Wide Field Electromagnetic Method in the Geological Mapping of Benxi Ore Concentration Area

Proceedings of the 7th International Conference on Environment and Engineering Geophysics & Summit Forum of Chinese Academy of Engineering on Engineering Science and Technology ◽

10.2991/iceeg-16.2016.26 ◽

2016 ◽

Author(s):

Bing Zheng ◽

Diquan Diquan Li ◽

Maojun Tian

Keyword(s):

Geological Mapping ◽

Electromagnetic Method ◽

Wide Field

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The Development of Near-source Electromagnetic Methods in China

Journal of Environmental and Engineering Geophysics ◽

10.2113/jeeg23.1.115 ◽

2018 ◽

Vol 23 (1) ◽

pp. 115-124 ◽

Cited By ~ 1

Author(s):

Guo-qiang Xue

Keyword(s):

High Efficiency ◽

Academic Research ◽

Electromagnetic Method ◽

Detection Accuracy ◽

Wide Field ◽

Transient Electromagnetic Method ◽

Transient Electromagnetic ◽

Detection Technology ◽

Deep Depth ◽

Central Loop

Near-source electromagnetic technology has been developed and applied in the exploration of petroleum, metallic ore, coal, and engineering geology due to its high efficiency, high detection accuracy, and deep depth of investigation. In this paper, research and applications of the frequency-domain electromagnetic sounding method (FDEM), wide-field electromagnetic method (WFEM), modified central-loop transient electromagnetic method (TEM), and short-offset grounded-wire TEM (SOTEM) with obvious near-source characteristics, were reviewed and analyzed. From the 1960s to 1990s, the FDEM method and equipment were extensively developed in China. These methods have played important roles in the exploration of coal resources. Based on controlled source audio-frequency magnetotelluric (CSAMT) and FDEM methods, a new method has been developed by deriving a new expression to calculate apparent resistivity. This method, which is referred to as WFEM, has been studied, applied, and received great attention in China. To increase work efficiency and reduce the influence of local transverse anisotropy on the detection processes, a modified central-loop TEM detection technology based on the central loop transient electromagnetic method was developed in China. The advantages of SOTEM in near-source surveys with high resolution and increased depth detection stimulated academic research interest to further develop grounded-wire TEM techniques. [Figure: see text]

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Application of a Wide-Field Electromagnetic Method for Hot Dry Rock Exploration: A Case Study in the Gonghe Basin, Qinghai, China

Minerals ◽

10.3390/min11101105 ◽

2021 ◽

Vol 11 (10) ◽

pp. 1105

Author(s):

Hui Tan ◽

Fan Ling ◽

Zhenwei Guo ◽

Jie Li ◽

Jiawei Liu

Keyword(s):

Mineral Resources ◽

Wide Field ◽

Qinghai Province ◽

Hot Dry Rock ◽

Good Potential ◽

Subsurface Resistivity ◽

And Inversion ◽

The Relationship ◽

Gonghe Basin

Hot dry rock (HDR) is a geothermal resource with a high temperature that is widely distributed and has good potential as a clean and renewable energy source. To determine underground electrical structures and to predict granite reservoir distributions, the wide-field electromagnetic (WFEM) method has been applied to explore deep mineral resources and has advantages such as explorations at greater depths and at high resolutions. In this study, a WFEM investigation was carried out for HDR exploration in Gonghe Basin within Qinghai Province. Six parallel survey lines, each spaced apart by 1 km, were designed for WFEM data acquisition. After data processing and inversion, we mapped the subsurface resistivity distribution and divided the inversion resistivity of HDR in the Qiabuqia area into four layers. From the WFEM results, we inferred the location of HDRs, which was verified using drilling wells. HDRs were found at a depth between 3200 m and 3705 m in the well. Furthermore, with the calibration of drilling well GR1, we provided the relationship between temperature and inversion resistivity. From this relationship, the exploration areas with mining potential can be determined.

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