Guizhou Province ranks third in China in terms of identified phosphate resources, and ranks first about its high-grade phosphate resources. Currently, it hosts the largest phosphate chemical base in Asia. Comparative studies on the Early Sinian phosphate-bearing rock series in central Guizhou Province aim to enhance the understanding of the Qianzhong ancient land or Qianzhong uplift, which are of significant importance for the prediction and exploration of deep phosphate resources. This work took the phosphate-bearing rock series profile of the Dawan phosphate deposit in the Wengfu area of Guizhou as a comparative standard. Through the re-examination of the lithological section of the phosphorite series, the phosphorite layers and phosphorites, the well-developed phosphate-bearing rock series of the Dawan phosphate deposit was divided into two lithological sections and six lithological layers. Vertical and horizontal profile analyses and comparisons were conducted to summarize their characteristics and variations, thereby analyzing the sedimentary environment and facies around the Qianzhong ancient land or Qianzhong uplift. It is suggested that the sedimentary base of the phosphate-bearing rock series is uneven, with greater deposition thickness in depressed areas and erosion or depositional gaps in raised areas. The Qianzhong ancient land covers a small area, with shallow water platform sediments of the Yangshui Formation around and within the ancient land, and deeper water slope sediments of the Doushantuo Formation further away from the ancient land. The Early Sinian sedimentary environment around the ancient land varies greatly, suggesting a multi-island uplift. Within the range of the multi-island uplift, there are favorable geological conditions for mineralization, indicative of a good potential for deep phosphate resource exploration.

In the process of geothermal reinjection, some geothermal fields are facing shutdown due to the reinjection water flow being much smaller than the designed. This work took a block of Guantao Formation geothermal reservoir in Baoding City as the research area in order to solve the problem of lower water injection during the reinjection process. Numerical simulation software was used to couple the thermal field with fluid dynamic field, and numerical simulation calculations were carried out for four different non-homogeneous strata to establish the evaluation method of maximum reinjection flow rate. The results show that the maximum reinjection water flow decreases with the intensification of planar heterogeneity, and the reinjection effect decreases as low as 35% of that in homogenous strata. The planar heterogeneity in the area between reinjection and production wells can affect reinjection effectiveness by 20% to 65%. This method can reasonably adjust the planar heterogeneity and reinjection flow rate, and effectively ensure the reinjection performance, which can be extended to other reservoirs with similar geological conditions.

The Xiaoshan region in western Henan Province is an important Au-Ag-Mo-Cu-Pb-Zn polymetallic ore concentration area in China. The Puzhengou lead-zinc deposit in this region is a hydrothermal type deposit, which is the first lead-zinc deposit discovered on the western margin of the Puzhengou rock mass. This lead-zinc deposit is expected to reach a medium scale, and associated element indium reaches a large scale. The application of multidisciplinary and multi-mean comprehensive prospecting methods can effectively improve the accuracy of geological, geophysical, and geochemical anomaly interpretation. Taking the Puzhengou lead-zinc polymetallic deposit as an example, this work utilized comprehensive geological-geophysical-geochemical information, and first established a prospecting model for hydrothermal vein type lead-zinc polymetallic deposits (associated with rare elements such as indium, thallium, cadmium, etc.) in the east Qinling metallogenic belt. We also summarized the exploration workflow, in an attempt to provide reference and guidance for searching for similar lead-zinc polymetallic deposits in this region. The geochemical characteristics of the deposit are mainly element combination anomalies of lead, zinc and silver, accompanied by anomalies of gold, tungsten, arsenic and molybdenum. The geophysical characteristics of the deposit are weakly polarized and low-to-medium resistivity-dominated IP anomalies. The selection of exploration workflow and method is as follows: first of all, the 1∶200, 000 and 1∶50, 000 stream sediments in the study area were comprehensively studied, in order to narrow the scope of key prospecting targets. Secondly, we selected a combination of soil geochemical exploration and induced polarization gradient profile to verify stream sediment anomalies and further narrow the scope of key target areas. Subsequently, an integrated geological-geochemical method combining rock geochemical profiles and trench sampling was implemented to determine the genesis of soil anomalies and evaluate the mineralization potential within surface fault-related alteration zones. Finally, a geological-geophysical prospecting approach incorporating high-power time-domain induced polarization sounding and drilling was deployed to delineate and confirm the extension of ore bodies at depth.

The northern Chifeng region of Inner Mongolia contains abundant lead-zinc, silver, tin, tungsten, copper, lithium, beryllium, niobium,tantalum, molybdenum, and iron resources, making it significant in the nonferrous metal-rare metal-silver metallogenic belt of the southern GreatXing'an Range. Previous studies have conducted extensive geological, geophysical, geochemical, remote sensing, and mineral resource surveys in thesouthern Great Xing'an Range, particularly in the Chifeng area. However, there is still a lack of effective prospecting methods for shallow overburdenareas. Considering the metallogenic geological background and spatial distribution patterns of deposits in this region, this study employed multi-sourceremote sensing technology to extract mineralization alteration in Hexigten Banner and Linxi County, northern Chifeng. Multispectral data (Landsat-8,ASTER) were used to extract alteration of different mineral types through principal component analysis. For GF-5 data, the mixed-tuned matchedfiltering technique was applied to extract mineralization alteration. The results from the three remote sensing methods were then integrated forcomprehensive analysis to delineate prospective metallogenic targets. We also conducted field verification, further advancing the application of remote sensing in geological and mineral resource exploration. Based on Landsat-8 and ASTER multispectral data, iron-stained and hydroxyl-bearing (Mg-OH, Al-OH) mineral information was extracted. Three alteration minerals of muscovite, epidote, and kaolinite were identified based on the GF-5 data.Field verification confirmed that the remote sensing extraction results corresponded well with actual alteration anomalies, and tin-copper-silver-leadzincmineralization was discovered within the delineated target areas. This study, by combining extraction and overlay results from different data sourcesand validating them through field surveys, demonstrates the accuracy of the remote sensing methods used for mineralization alteration extraction. Theintegration of multispectral and hyperspectral remote sensing data facilitates subsequent alteration zoning analysis and more precise metallogenicprediction, thereby better serving mineral resource exploration and related fields.

This work attempts to identify the characteristics of gas and liquid transport under different horizontal borehole trajectories in order to promote the efficient production of coalbed methane (CBM). The software Fluent was applied to simulate the two-phase gas and liquid transport under different horizontal sections of borehole trajectories, and the gas-liquid transport features under four types of horizontal section borehole trajectories (upward inclined, downward inclined, bow shaped, and spoon shaped) were obtained. We also analyzed the retention effects of liquids in the horizontal section under the four types of borehole trajectories, and proposed the drainage and production technology for efficient gas and liquid production. The results show that under different gas-liquid flow rate ratios, there were flow states in the upward inclined wellbore trajectory, including bubble flow, laminar flow, and annular mist flow. These flow states such as bubble flow, laminar flow, slug flow, dispersed flow, and annular mist flow were observed in the downward inclined and bow shaped wellbore trajectories. There were laminar flow, slug flow, and annular mist flow in the trajectory of the spoon shaped wellbore. The liquid retention intervals for the four types of wellbore trajectories, namely upward inclined, downward inclined, bow shaped, and spoon shaped, were 670~700 m, 0~300 m, 0~180 m, 650~700 m, and 0~320 m, respectively. The proportions of retention areas were 4.28%, 42.86%, 32.86%, and 45.71%, respectively. During annular mist flow, the gas carrying effect can promote liquid production and reduce the retention effect of liquid. When the gas-liquid flow rate ratio was 6.667, it can transition from slug flow to annular mist flow. During the gas production stage of coalbed methane wells, by adjusting the casing pressure and bottomhole flow pressure in the actual production process, the daily gas production of coalbed methane wells can be rapidly increased, which can achieve efficient production of gas and liquid. This research result can provide a theoretical basis for the CBM drainage and production wells in different horizontal wellbore trajectories during the gas production stage.

The geological survey of Mengjiaya deep-buried tunnel of Yifu railway was carried out by using the space-time array hybrid source electromagnetic method. This method integrates the advantages of natural and artificial field source electromagnetic exploration, and uses a unified theoretical model and observation equipment. It can collect three types of exploration data: remote reference magnetotelluric, controlled source magnetotelluric and wide-area magnetotelluric data in one arrangement, which will greatly improve field work efficiency and exploration accuracy. The anti-interference algorithm designed for the strong interference area was used for fine denoising, and finally the nonlinear conjugate gradient method (NLCG) and the lateral constrained quasi-two-dimensional (LCI) method were used for inversion. The inversion results were consistent with the geological data. At the same time, combined with the existing geological data, it is inferred that the shallow strata of the Mengjiaya tunnel are layered, low-resistivity Permian Qixia Formation limestone intercalated with coal strata. The deep strata are limestone, shale and quartz sandstone. There is a fault in the middle of the survey section (surface mileage CK172+875 section), and the surrounding rock mass is relatively broken. The exploration results are of great significance in guiding the next step of safe construction of the tunnel.

The Zhangjiapingzi gold deposit is a large-scale gold deposit within the Mianxi gold ore cluster in Sichuan Province. After years of exploration, the ore body has been exposed up to an elevation of 2600 meters above sea level, where mineralization is still present. Based on field geological surveys, this article systematically collected pyrite samples from multiple deep boreholes for in-situ pyrite thermoelectric testing. By studying the thermoelectric characteristics of pyrite at different elevations, a scientific basis is provided for deep mineral exploration. The results show that the thermoelectric coefficient dispersion of Zhangjiapingzi pyrite remains relatively stable but overall tends to be large (standard deviation >20). The thermal conductivity type of pyrite at different elevations is mainly P-type, indicating that the deposit is still in a shallow position, and there may be N-type deposits in some areas (at elevations of 2698 m and 2863 m) that are possible overlapping parts of the ore body. The formation temperature of pyrite is relatively low, indicating that it is still located in the shallow low-temperature layer as a whole. There is a phenomenon of overlapping high and low temperatures at the beginning and end of the ore body locally. The thermal conductivity gradient Y value of deep pyrite is relatively small, and the erosion degree of the deposit is only about 50% based on the calculated erosion rate (γ). Based on various thermoelectric parameters,we believe that the Zhangjiapingzi gold deposit has great mineralization potential, and the deep areas controlled by faults and the lateral extension direction of the ore body are favorable exploration spaces.

The Zhule area in Xizang is a newly discovered mineralization spot in the continental volcanic rock area in the southwest section of theBangongco-Nujiang belt. There are lithocap and mineralization clues on the surface, which reveals a great potential for prospecting. This articleconducted a detailed anatomical study on the lithocap in the Zhule area based on short-wave infrared technology. On the basis of identifying the types ofalteration in the region, the alteration mineral assemblages were determined, the spectral characteristics of typical alteration minerals were analyzed, andminerals spectral indicators were established to speculate the location of hydrothermal center. The research indicates that the lithocap is characterizedby strong silicification and sericitization, and the altered mineral assemblages mainly include six categories: sericite ± illite ± montmorillonite, sericite ±montmorillonite ± jarosite, sericite ± illite ± carbonate, sericite ± chlorite, alunite, pyrophyllite ± kaolinite ± dickite ± diaspore. Based on the analysis ofthe altered minerals and spectral characteristics theory of typical minerals, the identification of altered minerals that sericite with high SWIR-IC (>2.4),alunite with high Pos1480 (>1483 nm), and high Pos1430 (>1433 nm) can serve as spectral indicators for inferring hydrothermal center and narrowingthe exploration target area. Based on the short-wave infrared study of surface altered minerals in the Zhule area, one potential areas for hydrothermalcenter have been delineated, which can provide theoretical basis for subsequent deep mineral exploration.

Hydrogeology exerts a major effect on the enrichment and productivity of coalbed methane (CBM). In view of the productivity difference in CBM wells with different water production levels in Xinjiang, this work conducted statistical analysis and numerical simulation to divide the CBM wells into three types, i. e., low water-producing, medium water-producing and high water-producing CBM wells. Those wells with an average daily water production of < 5 m3 for 500 days were classified as low water-producing wells. This type of wells has a moderate pressure drop (the pressure drop of the well CS18 is 51.56%), a limited range of pressure degradation and absorption, and the gas supply area is small. The CBM wells with an average daily water production of 5~10 m3 are divided into medium water-producing wells. These wells have a moderate pressure drop (the pressure drop of the well BCS-22 is 53.67%), and rarely encounter the situation that the water production is too large to be desorbed by long-term drainage. CBM wells with an average daily water production of more than 10 m3 are classified as high-yield wells. The pressure drop of such wells is small (the pressure drop of wells T1-6 is 30.42%), and the drainage and pressure reduction are difficult. Further suggestions were put forward for the CDM wells, including "reasonable water control and appropriate pressure holding" for low water-producing wells, "continuous production and stable water and pressure" for medium water-producing wells, and "daily decrease in low casing pressure and high flow pressure" for high water-producing wells. This study can provide a basis for the long-term and efficient development of CBM wells with different water production levels in Xinjiang.

During a special historical period, shallow coal seams in northern Shaanxi suffered from a large number of illegal open-pit mining and overexploitation due to spontaneous combustion control, resulting in a wide area of goaf, strong concealment, and difficult exploration, which has seriously affected the safe mining of shallow coal seams. To solve the above-mentioned problems, a comprehensive exploration technology combining historical satellite images, oblique photography, and geophysics was applied to the goaf exploration in a Shenfu mine of northern Shaanxi under complex conditions. The historical satellite image data reveals obvious mining traces in the southwest side of P2 waste dump and other areas. By comparing oblique photography, the approximate distribution range of the mining site and hidden goaf can be further divided. On this basis, a reasonable arrangement of geophysical survey lines was made, and the results showed that the electrical layer corresponding to the coal-bearing strata under the P2 waste dump was significantly lacking in high resistance characteristics in local areas. Among them, the resistivity of coal-bearing strata between the high-density resistivity method ERT-3 measuring line (0~225 m) decreased from 120 Ω· m to below 60 Ω· m, and the resistivity of coal-bearing strata between the transient electromagnetic method TEM-2 measuring line (0~80 m) decreased from 160 Ω· m to around 60 Ω· m. Finally, the distribution boundaries of concealed goaf were determined by combining historical satellite imagery, drone oblique photography, high-density resistivity method, and transient electromagnetic method results. The advantages of the above multiple methods complement each other, which can achieve high-precision, high-efficiency, and low-cost exploration of goaf under complex conditions.