Geophysical Exploration Technology Research Articles

A multi-task learning network based on the Transformer network for airborne electromagnetic detection imaging and denoising

Abstract As an emerging geophysical exploration technology in recent years, airborne electromagnetic exploration has the advantages of adapting to diverse terrains, wide coverage, and providing a large amount of electromagnetic data, and can be applied to the rapid collection of large amounts of data. Scenarios are often used in fields such as deep geological structures, mineral resource exploration, and environmental engineering research. However, traditional airborne electromagnetic data inversion technology usually takes a long time to process a large amount of airborne electromagnetic data, and it is difficult to remove the noise in the later signals. Therefore, this paper proposes a multi-task learning network structure based on Transformer. By constraining the two network branches of imaging and denoising, a sub-network with simultaneous denoising and imaging is established to process aeronautical electromagnetic data. The noise test set is introduced for testing. This model achieved a 582.61% signal-to-noise ratio improvement in smooth Gaussian noise denoising, and a 129.69% and 112.74% signal-to-noise ratio improvement in non-smooth Gaussian noise and random impulse noise denoising, respectively. The method proposed in this article overcomes the shortcomings of traditional inversion imaging such as slow speed and low resolution, and at the same time eliminates the influence of noise in airborne electromagnetic data. This is of great significance for the application of deep learning in the field of geophysical exploration.

Application of integrated geophysical techniques in geothermal exploration in Binhai County, Jiangsu Province

AbstractIntegrated geophysical technology is a necessary and effective means for geothermal exploration. However, integration of geophysical technology for large‐scale surveys with those for geothermal reservoir localization is still in development. This study used the controlled source audio‐frequency magnetotelluric method technology for large‐scale exploration to obtain underground electrical structure information and micromotion detection technology to obtain underground wave velocity structure information. The combination of two detection technologies was used for local identification of geothermal reservoirs. Further, auxiliary correction and inversion constraint were implemented through the audio magnetotelluric sounding technology for maximum authenticity restoration of the near‐ and transition‐field data. Through these technology improvements, a geothermal geological model was established for the Binhai County of Jiangsu Province in China and potential geothermal well locations were identified. On this basis, a geothermal well was drilled nearly 3000 m deep, with a daily water volume of over 2000 m3/day and a geothermal water temperature of 51°C at the well head. It is found that predictions using the above integrated geophysical exploration technology are in good agreement with the well geological formation data. This integrated geophysical technology can be effectively applied for geothermal exploration with high precision and reliability.

Geophysical exploration strategy for Cu-Ni-Co deposits in China: A review

Nickel (Ni) and Cobalt (Co) deposits are important mineral resources, and China is the largest consumer of these resources. Magmatic, hydrothermal, sedimentary, and meta-sedimentary ore-bearing rocks are the most significant Co-Ni deposit types in China, accounting for 98% of the Co production. Thus, exploring the Chinese Co-Ni resources and reserves is beneficial for promoting its economic development. We have analyzed the metallogenetic geologic model and the physical characteristics of the rocks and ores of magmatic Co-Ni sulfide and hydrothermal Cu-Co deposits and the sedimentary and meta-sedimentary rocks that host the Cu-Co ore deposits to develop an effective geophysical exploration technology system. For magmatic deposits, the small ore-forming intrusion is the main detection target; in general, gravity, magnetic, and seismic exploration and artificial-source electromagnetic methods are widely used to determine the precise location of the ore-forming intrusion. For hydrothermal deposits, ore-controlling structures and favorable positions for mineralization (e.g., alteration belts) are the main exploration targets, and the combination of hyperspectral remote sensing, gravity, magnetic-excitation, chemical prospecting, and artificial-source electromagnetic detection techniques can help locating such ore body types. For sedimentary and meta-sedimentary ore-bearing deposits, a combination of soil debris geochemical exploration measurement, induced polarization (IP) scanning, gravity method, IP sounding, and the transient electromagnetic method has been used to scan and locate the ore-controlling and ore-bearing layers. Finally, upon selecting the Xiarihamu magmatic Co-Ni deposit in the East Kunlun orogenic belt as our study area, we have conducted controlled-source electromagnetic exploration and obtained reliable results. Our study can serve as a reference for determining the most effective geophysical technique for the exploration of Cu-Ni-Co deposits in China.

Preface

The 10th International Conference on Environmental and Engineering Geophysics (ICEEG) is hosted by China University of Geosciences, Beijing, China, from June 07-12, 2023. Held biennially since 2004, the ICEEG Conference is one of the most important events for geophysical research and applications in environmental and engineering. Drawing together scientists, engineers, industrial delegates and end-users, the conference is a place to see all of the advanced developments, ranging from fundamental achievement in geophysical methods to the most interesting case studies. Traditionally, the proceedings “Engineering Environmental Geophysics and Intelligent Detection Technology” of the 10th International Conference on Environment and Engineering geophysics is published for the readers from the near-surface geophysics communityShallow surface geophysics refers to the exploration theory and application research on the surface of the earth using physical principles and methods. The shallow surface supports the needs of human survival and development. On the one hand, human beings obtain water and minerals from it, and build the necessary underground space to contain water, electricity, gas, communication, transportation and other pipe network systems in modern cities. On the other hand, various kinds of waste generated by human activities is discharged and buried in it, forming a unique geological layer of the Anthropocene. Whether from the technical level (physics) or non-technical level (politics, society, law), shallow surface geophysics is becoming more and more important. Artificial intelligence technology has been widely used in various fields in recent years, and the construction of smart cities cannot be separated from the support of shallow surface geophysical exploration and monitoring methods and technologies. Due to the integration of urbanization and the development of geophysical technology in China, geophysicists have more opportunities for scientific research. In order to promote exchanges, improve the level of environmental and engineering geophysical exploration, and provide a first-class platform for extensive exchanges among workers engaged in scientific research, technology development and production applications in this field, the 10th International Conference on Environment and Engineering Geophysics will be held in China University of Geosciences (Beijing), a famous university of geosciences. We warmly welcome experts and scholars to contribute and participate in the conferenceIn the proceedings of 10th ICEEG, 160 peer-reviewed research expended abstracts are published according to the following topics: geophysical exploration of urban underground space, high frequency surface wave theory and application, ground penetrating radar technology and application, advances in shallow surface geophysics, engineering geophysics, hydrology and environmental geophysics, disaster geophysical survey, archaeological geophysics, unmanned aerial vehicle detection, smart city geophysics, intelligent detection technology, geophysical monitoring technique, geophysical instruments and software, shallow active source and passive source seismic detection, and young scientists forum.We are deeply grateful to the members of the scientific committee and institutional scientific partners of ICEEG: Chinese Geophysical Society, China University of Geosciences (Beijing), Shallow Surface Geophysical Committee of Chinese Geophysical Society, Professional Committee of Environmental Geophysics, Chinese Geophysical Society, Department of Earth Sciences, National Natural Science Foundation of China, China University of Geosciences (Wuhan), Central South University, Chengdu University of Technology, Chang’ An University, Institute of Geology and Geophysics, Chinese Academy of Sciences, China University of Mining and Technology (Beijing), Zhejiang University and Jilin UniversityWe would like to thank all reviewers for their great efforts to achieve the high quality of published articles.We would also like to extend our gratitude to all participants of 10th ICEEG for their interests and great contributions. Our special thanks go to the invited speakers for their significant contributions to the conference and the proceedings.We would also like to thank all the sponsors. It is your years’ support that makes the ICEEG conference a success.We would also extend our thanks to all committee members and student volunteers for their great efforts in organizing this wonderful event.We hope the proceedings show the challenges and the latest developments in the application of Engineering Environmental Geophysics and Intelligent Detection Technology.

Editorial for Special Issue “3D/4D Geological Modeling for Mineral Exploration”

With the development of high-precision geological observation technology, in situ mineral microanalysis technology, isotope geochemical analysis technology, deep geophysical exploration technology, deep drilling, real-time mining, remote sensing high-resolution hyperspectral image technology, and supercomputer and industrial intelligence, geoscience has entered an era of big data and artificial intelligence in the 21st century [...]

Application of Multi-Electrode Resistivity Method on Semi-Diagenesis Rocks in Freezing Area and Its’ Implications

Recently, with the development of geophysical exploration technology, geophysical engineering instruments and methods have also improved. The multi-electrode resistivity method is widely used in engineering exploration. In this paper, multi-electrode resistivity tests were carried out in a seasonal frozen soil area in Heilongjiang Province, to provide an optimized multi-electrode resistivity method under the conditions of frozen soil. Combined with shear wave velocity tests and standard penetration tests, multi-electrode resistivity tests were used to comprehensively analyze and evaluate the physical and mechanical properties of Tertiary semi-diagenesis rocks. The results show that the high resistivity due to the frozen surface layer acting as a shield can be eliminated by technical means. It is feasible to test the resistivity through the frozen surface layer. The multi-electrode resistivity method can visually reflect the interface between saturated sand and semi-diagenetic rocks. Dividing the interface between saturated sand and semi-diagenetic rocks is advantageous as the morphology of the resistivity curve has a significant curvature change. There is a strong correlation between the resistance and shear wave velocity of a strata in which the Pearson correlation coefficient is as high as 0.99. The multi-electrode resistivity method test used in combination with the shear wave velocity test and the standard penetration test could give the bearing capacity and frictional resistance of semi-diagenetic rocks, which saves a lot of time and material costs in engineering exploration.

Research on the Development Status and Practical Application of Geophysical Exploration Technology

Research on the Development Status and Practical Application of Geophysical Exploration Technology

Joint interpretation technology of favorable HDR geothermal resource exploration in Northern Songliao Basin

Hot dry rock (HDR) is considered a new clean and renewable energy source. China is rich in HDR resources, but viable and reliable resource evaluation techniques and exploration methods have not been available yet. This research method, consisting of deep exploration combined with shallow drilling, screens the geothermal anomaly regions using heavy magnetic, electric measurement, seismic and thermal joint interpretation technology, and verifies the geophysical multiplicity with massive oilfield drilling data to locate the favorable HDR target region. The research results show a regionally geothermal abnormal area. We use relative impedance combined with seismic profile to recognize the HDR target region. The geophysical exploration and geological joint interpretation technology are faster and more accurate than the single geophysical exploration technology. The comprehensive analysis believes that the high resistance granite body in the southern Paleo-central uplift zone, with its area 500km2, its thickness 150–330m, its static formation temperature reaching 152° in the depth of 3360m, its high rock thermal conductivity, its good deep fracture, and base fracture development, is a fragmented granite and weathered shell, easy for artificial reservoir re-constructing. There is high preciseness in locating the favorable target region for HDR development.

Development Strategy of Quantum-Based Deep Geophysical Exploration Technology and Equipment

Quantum-based sensing and measurement technology is a disruptive technology that can realize fine detection of the gravity and magnetic fields in deep Earth, and it has become a key development direction for geophysical exploration equipment worldwide. This study focuses on the frontier technologies for the quantum-based high-precision measurement of Earth’s gravity and magnetic fields, summarizes the development status of quantum-based geophysical exploration equipment, and analyzes demand for the superconducting quantum-based electromagnetic detection system, magnetic vector gradient detection system, superconducting gravity detection system, and cold-atom absolute-gravity exploration system during deep resource exploration. Moreover, the international trend of quantum-based high-precision measurement technology as well as the development opportunities and challenges in this field are analyzed. To improve the core technology research, complete localization, and exploration application of quantum-based geophysical exploration equipment in China, we propose the development goals, technical system, key tasks, and strategic planning for a new generation of quantum-based high-precision deep geophysical exploration equipment. This aims to achieve breakthroughs in superconducting quantum chips and high-sensitivity sensors, establish a collaboration model for the independent development of China’s quantum-based geophysical exploration equipment, promote the high-quality development of deep exploration equipment, and provide strategic support for solving major problems associated with deep mineral resource exploration and revealing of Earth’s deep structure.

SYMPOSIUM “Advanced Geophysical Exploration Technology; Improvements and Issues for Subsurface Evaluations” (Summary of closing remarks)

SYMPOSIUM “Advanced Geophysical Exploration Technology; Improvements and Issues for Subsurface Evaluations” (Summary of closing remarks)

SYMPOSIUM “Advanced Geophysical Exploration Technology; Improvements and Issues for Subsurface Evaluations” (Opening remarks)

SYMPOSIUM “Advanced Geophysical Exploration Technology; Improvements and Issues for Subsurface Evaluations” (Opening remarks)

Research on Airborne Electromagnetic Whole-area Apparent Resistivity Imaging Algorithm in the Detection of Goaf in Rail Transit

Depth apparent resistivity imaging is an important process of data processing and analysis in the aviation transient electromagnetic method. It can provide reference value of conductor depth, vertical extension, and other information, and can accurately provide the measurement of each aviation transient electromagnetic measurement system. The structural section of the apparent conductivity of the one-dimensional layered medium on the line. As an advanced geophysical exploration technology, the aerial transient electromagnetic method has been applied significantly in the exploration of polymetallic minerals abroad in recent years. In this paper, based on the theory of ground-to-air transient electromagnetic method with multiple radiation sources, a corresponding multi-component global apparent resistivity definition method is established. The advantages of using the magnetic field strength to define the global apparent resistivity of the multi-radiation field source ground-air system are analysed. For each component of the magnetic field strength, respective global apparent resistivity algorithms are proposed to realize the multi-component, full-time, and full-space visual resistivity. The resistivity is calculated, and the influence of the offset on the global apparent resistivity is analysed. By adjusting the relative position of the source and the current direction and other parameters, the multi-radiation source transient electromagnetic ground-air system can not only strengthen the signal strength of different components, weaken random interference, but also better distinguish the location of underground anomalies

Application of Geophysical Exploration and Drilling Technology in Mine Water Control

Application of Geophysical Exploration and Drilling Technology in Mine Water Control

Soil-epikarst structures and their hydrological characteristics on dolomite slopes in karst region of southwest China

Epikarst is the core area of karst critical zone, with important hydrologic regulation and storage function. However, the effects of karst development degree on hydrologic characteristics of epikasrt is still unclear. We used geophysical exploration and hydrogeological techniques, combined with the dynamic monitoring of moisture and water levels, to quantify the karst development degrees and their hydrologic characteristics on slope lands. We analyzed the responses of soil-epikarst systems to rainfall. Results showed that geophysical exploration technology could be well applied to the detection of surface-subsurface structures in the karst areas. The average thickness of soil and surface karst zone on the slope was less than 0.63 m and 2.60 m, respectively. The slopes of strong-karstification characterized by high apparent resistivity, well-developed joint fractures, and strong permeability (0.73 m·d-1). Such a result indicated that epikarst could regulate precipitation. The responses of soil moisture had a larger rainfall threshold (>20.50 mm·d-1) and the water level was determined by rainfall amount. In contrast, the slope with weak-karstification had low apparent resistivity and weak permeability (0.07 m·d-1). Moisture and water level were sensitive to rainfall. Karst channels were developed locally at 240-300 cm with a permeability coefficient of up to 432 mm·d-1. Obvious preferential flow was observed in extreme rainfall events on this slope, which could induce flood disaster in the adjacent depression. Our results would provide scientific basis for further research on water resources regulation, management, and eco-hydrology in karst areas of southwest China.

KAMBRİYEN KİREÇTAŞININ KARSTLAŞMA SÜRECİNİN FARKLI ARAŞTIRMA TEKNOLOJİLERİ İLE ANALİZİ

Coal mine floor limestone aquifers are a major source of water inrush from the coal seam floor and a serious threat to the safety of coal mining. In order to reduce and avoid the occurrence of water inrush within the coal mine, we use multiple detection techniques, which are geophysical exploration technology, drilling technology, water inrush accidents and tracer test, to develop a multi-faceted exploration of karst development and analyze its development characteristics in the Chaochuan mine No. 1 well. The results show that, the Cambrian limestone (CL) karst water is poor; there is a certain hydraulic connection. Near faults F5, F1, F125, and SF28, the area is less water-rich area, and the deep karst water forms a closed area; 61.54 % of shallow water inrush accidents in the Taiyuan limestone and CL karsts were caused by large tectonic and nearby shallow faults. The karst vertical zonation is shallow; the shallow water level decreased more in the West Wing of the No. 1 well than in the East Wing.

Research on Application of Computer Technology in Petroleum Geophysical Exploration

With the development of society, people’s demand for oil is increasing. Petroleum is a necessary resource for mankind, and the difficulty of geological exploration for petroleum resources has increased. In the geological exploration of petroleum resources, using geophysical exploration technology can improve the extraction efficiency and the quality of oil resources, this reduces the waste of oil resources to a certain extent.

The Helicopter Time-Domain Electromagnetic Technology Advances in China

The helicopter time-domain electromagnetic (HTEM) method is a method that uses geophysical exploration technology and a helicopter platform to carry electromagnetic detection equipment. HTEM has developed rapidly, in both theoretical and technological terms, in recent years because of its high efficiency, ability to drape steep and variable terrain, large detection depth, and high resolution. This work briefly introduces the HTEM technology principle and forward and inversion theory, summarizes the main performance parameters of international representative HTEM systems, and analyzes the performance and structural characteristics of VTEM, SkyTEM and HeliTEM systems. To provide a technical reference for scholars engaged in HTEM instrument technology, we analyze the factors affecting the detection capability of HTEM systems and the main difficulties in system design. Taking China’s HTEM systems as the object of analysis, we introduce the key technologies behind the systems in detail, including high-power transmitting, receiving sensor design, and motion-noise-suppression technologies. This work also discusses the development trend of HTEM and the existing technical problems, including detection depth, measurement accuracy, and noise refinement classification, providing ideas for the further development of HTEM technology in the future.

Technology of detecting deep underground metal pipeline by magnetic gradient method

The application of trenchless technology, such as pipe pulling, pipe jacking, directional drilling and so on, makes the deep buried underground pipeline more and more in the project, and most of the geophysical exploration technology has poor detection effect, which makes it become the difficulty in the underground pipeline detection. This paper mainly expounds and analyzes the principle and construction method of magnetic gradient method for detecting deep underground pipelines, and introduces the application of magnetic gradient method in the detection of deep underground pipelines with two natural gas pipelines in Shijiazhuang road project.

Study on the application of comprehensive geophysical prospecting technology for the goaf detection in coal mine

Aiming at the problem that drilling technology is time-consuming and challenging to be used to explore the goaf of a coal mine, a comprehensive geophysical exploration technology is proposed to quickly delineate the goaf. Through the layout of the TEM survey line to survey the development characteristics of goaf in the work area, and then with the help of magnetotelluric sounding method to verify the goaf delineated by TEM, the abnormal area of apparent resistivity obtained by the two methods were basically consistent. And it is consistent with the mining data of coal face. Based on the comprehensive geophysical exploration technology, the problem of multiple solutions of a single geophysical exploration method is solved, which provides technical support for the exploration of goaf in similar projects in this area in the future.

Analysis on the Important Application of Geophysical Exploration Technology

Geophysical prospecting technology is widely used in current geological exploration, metal exploration, oil and gas resources exploration, etc. This technology has many advantages such as low cost, high efficiency and good accuracy of survey results, and plays an important role in many industries. At present, the level of geophysical prospecting technology in China is constantly improving, and its application effect is also constantly improving, so it is necessary to clarify the key application points of this technology. Therefore, this paper will conduct in-depth research and Analysis on the important applications of geophysical exploration technology, elaborate the basic concepts and specific applications of geophysical exploration technology, and put forward some reasonable opinions and measures, in order to further improve the application level of this technology.