Hot dry rock (HDR) is a kind of clean and renewable geothermal resource. The utilization of HDR is of great significance to the improvement of energy structure of Guangxi. The early studies show that the eastern and southern areas of Guangxi have HDR development potential. Based on Guangxi aeromagnetic survey data, the Curie point depth was calculated by using Parker-Oldenburg interface inversion method. The terrestrial heat flow values and temperatures at several different depths were also calculated. It is found that the calculation results are consistent with the actual measurement temperature data, indicating that there are formation conditions for the HDR resources in Xichang and Changle sags in Hepu basin. The reservoir and seal conditions of the HDR resources in Hepu basin were analyzed based on the basic geological survey and a large number of borehole data. Two hot-dry rock exploration target areas C1 and C2 located in Xichang and Changle sags were initially circled, with an area of 167.10 km² and 72.90 km², respectively. The HDR resources are 182.48×10¹⁵ J in C1, and are 77.59 ×10¹⁵ J in C2. Based on 20% recovery rate, the total amount of HDR resources in Hepu basin is 52.01×10¹⁵ J, which is equivalent to 177.48×10⁴ t of standard coal. It accounts for 4.72 % of the total energy production of 3756.69×10⁴ t standard coal in Guangxi in 2018. Based on the resource evaluation, it is recommended that further exploration should be given to the C1 target area,which is located in Xichang sag of Hepu basin.

Deep seismic reflection technology is an important method to detect the deep structure of large-scale metallogenic belt and ore concentration area and reveal the background of mineralization. The authors explored the subsurface structure of the magmatic fluid passage in the vicinity of the Tibetan Niangre ore concentration area with iron, copper and other polymetallic deposits in the middle section of the Gangdese metallogenic belt, revealed the background of the mineralization and the corresponding fracture formation. Through the data processing such as tomostatics, de-noising, and predictive deconvolution of the 130 km deep seismic reflection profile crossing the Niangre ore concentration area, we obtained the reflected images of the upper crustal structure of the Niangre ore concentration area. Based on the geologic and geophysical data in this area, we studied the upper crustal structure of the ore concentration area, and found out the spatial relationship between the seven existing faults in the area and the distribution of the veins in the Gangdese metallogenic belt, and point out that some special structures such as the bright spot structure control the magma activity rising channel, and closely connected with the deposits.

Taking for example the main oil and gas production formations of carbonate in Callovian-Oxfordian of Samandepe gas field, Amu Darya basin, Turkmenistan, and settings about the sedimentary facies, diagenesis means, diagenetic evolution sequence and corresponding products of geologic process, the authors make a comprehensive research on diagenetic environment and diagenetic fluid property reflected by the geochemical behavior, such as trace element, Fe, Mn, Sr, stable isotope, C, O, Sr, fluid inclusion, and cathode luminescence. According to the “hydrologic system”, CallovianOxfordian are divided into three diagenetic system, seawater-freshwater,compaction brine and deep cycle temperature and pressure water in different diagenetic stage. The deposition and diagenetic system have a good coupling relationship with reservoir in the space and time, which can be classified as: ①Platform edge reef and shallow facies control the regional distribution of reservoir. ②The early-denudation of fresh water system, and the shallow burial dolomitization of compaction brine diagenetic system in early-diagenetic stage are the key to forming reservoir. ③Buried denudation of the diagenetic system of temperature and pressure water, middle-deep buried dolomitization and tectonic disruption action in mid-diagenetic stage enlarge the reservoir scale, promote the reservoir quality, and contribute greatly to the development of high-grade reservoir.

The Dashihugou porphyry copper deposit in eastern Liaoning Province is located in the Liao-Ji orogenic belt at the northeastern margin of the North China craton, and its mineralization is spatially closely related to the diorite porphyrite veins intruded into Dashihugou granites. This paper reports for the first time the formation age of diorite porphyrite and its zircon genesis, discusses its metallogenic potential, and provides a theory for regional prospecting. Zircon U-Pb isotopes and trace elements of diorite porphyrite were determined by LA-ICP-MS. Zircon U-Pb dating results show that the emplacement time of diorite porphyrite is 225.6-218.7 Ma, which belongs to the Late Triassic. The study indicates that the magmatic activity of this period is closely related to the first stage of copper mineralization at the same time. Zircons have a typical magmatic origin, and trace elements have characteristic of high REE abundance values with ΣREE content of （216.3-1 305.9）×10-6. Meanwhile, zircons have positive Ce anomaly and weak negative Eu anomaly. The formation temperature of zircons is 568-913 ℃ using Ti thermometer and the oxygen fugidity ranged from ΔFMQ-0.05 to ΔFMQ+4.05, which indicates that the granite has metallogenic potential of porphyry-type copper deposit. Combined with the regional geological tectonic history and zircon trace element characteristics, the magmatic activity of this period may be related to the partial melting of the lower crust caused by the upwelling of the asthenospheric mantle related to plate segment detachment during the continental deep subduction process.

 It is of great significance for the efficient development of sandy braided river reservoirs to clarify the different characteristics and genesis of the same level architecture elements. Based on modern deposit, field outcrop, and core, the quantitative architecture characterization was carried out in typical layers by taking the sandy braided river of lower He8 Member in Sulige gasfield as the study subject. Architecture differences were emphatically compared from the fifth to third level in typical layers of H8x2-2, H8x1-3, and H8x1-1. Influenced by source condition and base level change, the braided belt scale of lower He8 Member changes from 650.0 m to 1 750.0 m. The single braided belt has three different distribution patterns: Isolated type, lateral splicing type, and vertical superposition type. Architecture differences in individual sandbody are remarkably affected by flooding, channel erosion, and chute scour. The scale of braided river bar is greater with an average thickness of 7.2 m in the layer of advantage lithofacies probability higher than 80%. The average length and width are 1 402.0 m and 809.0 m in H8x2-2. The architecture differences of the third level are minor in braided bar. Falling-silt layers have the similar feature of thin, gentle and lenticular distribution. They are 0.1-0.4 m thick and with a dip angle of 1-3 degrees. Single lateral accretions are 360.0-565.0 m wide. The number of lateral accretions and the single size control the difference in the average bar scale in every layer. With the constraint of architecture differences in different levels, a three-dimensional geological model is built up to accurately reflect the distribution of sandy braided river architecture in Sulige gasfield, which can provide a reference for later development adjustment of the reservoir.

In order to reveal the characteristics and genesis mechanism of the deep reservoir in Lufeng sag of Pearl River Mouth basin, this study systematically analyzed the influence of sedimentary environment, abnormal pressure, geothermal gradient, and hydrocarbons charging on the anti-compaction ability of reservoir. The results show that the Paleogene reservoirs with a buried depth of more than 4 000 m in Lufeng sag are still featured by primary pores. The mineral composition of the reservoir is mainly quartz sandstone, and the overall performance is low-medium permeability reservoir. The underwater distributary channel of braided river delta has stable flow action. The long distance transport makes the grain size distribution of rock more uniform and the integral number of mixed matrix less, which are favorable conditions for the development of primary pores. The abnormal pressure formed by mudstone undercompaction transferred to sandstone reservoir can effectively reduce the damage of compaction to pore space. The plasticity and ductility of rock are relatively weak under low geothermal gradient, which slows down the compaction rate of rock. In addition, the oil and gas generated from the source rocks of the fourth member of Wenchang Formation occupied the reservoir space after entering the reservoir, which effectively inhibited the damage of the later compaction and cementation to the reservoir pores. Under the coupling control of four controlling factors, the primary pores of deep reservoir in Lufeng sag are widely developed.

Mesozoic volcanic rocks widely developed and show significant hydrocarbon potential in Bozhong Sag, Bohai Bay basin. However, there is still a lack of in-depth understanding of the reservoir-forming mechanism of high-quality Mesozoic volcanic reservoirs. Based on the analysis results of blue dye thin section, scanning electron microscopy, physical property test, high-pressure mercury injection, nuclear magnetic resonance, and nitrogen adsorption, the reservoir spaces, porosity and permeability, microstructure of pores are analyzed, and the forming mechanism and distribution of high-qualitty reservoir are discussed. The Mesozoic volcanic reservoirs were divided into two types, high porosity with mid-low permeability (Class Ⅰ reservoir), and mid porosity with low permeability (Class Ⅱ reservoir). The low porosity with low permeability volcanic rocks can not form effective reservoirs (Class Ⅲ, non-reservoir). The Class Ⅰ reservoir is composed of intermediate-acid vesicular lava altered by cryptoexplosive brecciation and dissolution. The Class Ⅱ reservoir is composed of massive intermediate-acid lava altered by cryptoexplosion brecciation and dissolution, or basic vesicular lava altered by dissolution. The main forming mechanism of favorable volcanic reservoirs in the Bozhong sag benefitted from the primary pore, fracture, dissolution, and devitrification. A reservoir development model is established, which is characterized by vertical multi-layers and lateral multi-centers of high-quality volcanic reservoirs under weathering background. Two types of volcanic bodies, multi-eruption unit, multi-mound superimposed acid composite lava volcano, and intermediate-acid intrusive lava dome, are important exploration targets for high-quality volcanic reservoirs in the Bozhong sag.

Existing drilling and seismic data reveal that Mesozoic strata are widely developed in the southern South China Sea (SCS)．In order to further understand the distribution characteristics and oil and gas geological significance of the Mesozoic strata in the southern SCS，the latest satellite gravity data are used to invert the depth and thickness of Mesozoic strata in this paper．Firstly，the gravity field forward modeling technique is used to eliminate the influence of the sea water，and the Bouguer gravity anomaly in the southern SCS is obtained． Secondly，in order to eliminate the influence of the Cenozoic sedimentary layer，this layer is divided into three layers： 0-3 km，3-6 km and 6-10 km． According to the relationship between density and depth obtained by predecessors in the SCS，the gravity influence of Cenozoic sedimentary layers is calculated by using the variable density Parker forward modeling method, and it is subtracted from the Bouguer gravity anomaly． The Pre-Cenozoic gravity anomaly was obtained. On this basis，the wavelet multi-scale decomposition technique is used to eliminate the gravity influence of deep Moho and local rock mass，so as to calculate the gravity anomaly derived by Mesozoic strata．Finally，the depth and thickness of Mesozoic strata in the southern SCS are derived by using the 3D Parker variable density interface fast inversion technique． The inversion results correspond well with the known Mesozoic wells． The Mesozoic strata in southern SCS are mainly distributed in Liyue Bank, the north part of Palawan Island and Wan’an area，with the thickness less than 9 km，while in most other areas less than 1 km or no Mesozoic strata．The Mesozoic is the most developed in Liyue Bank area, followed by the northern part of Palawan Island. Combined with the previous research results of oil and gas geological conditions in this area, it is concluded that the Mesozoic of Liyue Bank area in the southern SCS has a good oil and gas exploration prospect.

Gaobei felsic dikes are exposed in the middle of the Yushan metallogenic belt, south Jiangxi Province, intruding into the Precambrian metamorphic strata, and their rock type is mainly granite porphyry. In order to reveal the emplacement age, petrogenesis and relationship with mineralization in the Gaopi ore deposit in south Jiangxi Province, petrography, geochemistry, zircon U-Pb dating and Hf isotopic analyses were carried out on the Gaopi granite porphyry. The results show that the Gaobei granite porphyry is characterized by high silicon (74.53% on average), high potassium (4.34% on average) and aluminum-rich (15.36% on average), and belongs to the high-k calc-alkaline series or k-basalt series granite; It has a low Nb/Ta, Zr/Hf ratio, and the REE fractionation is not obvious with strong Eu negative anomaly, proving to be highly differentiated granites. Zircon LA-ICP-MS U-Pb data has yielded concordant age of (135.73±0.46) Ma (MSWD=1.7), and a mean age of (135.62±0.92) Ma (MSWD=0.27), indicating that the Gaobei granite porphyry was emplaced in Early Cretaceous. Zircon Hf isotope analysis results show that the 176Hf/177Hf=0.282322-0.282450, εHf（t）=-13.3--8.5, and the two-stage model age TDM2 varies from 2.03 Ga to 1.73 Ga, inferring that the Gaobei granite porphyry may be mainly derived from the melting of the Proterozoic crustal materials. The field investigations found that the surrounding rocks around the Gaobei ore deposit have undergone intense hydrothermal alterations such as argillization, beresitization, and silicification, and are distributed in a planar pattern. Meanwhile, the borehole has revealed net-vein molybdenum mineralization, inferring that the deep area has the potential for porphyry molybdenum deposits.

In order to reveal the formation mechanism of the NE trending strike-slip faults in the north slope of Tazhong region, based on previous studies, this paper designed a structural physical simulation experiment platform by using the principle of similarity analysis, completed three sets of structural physical simulation comparison experiments, simulated the formation and evolution process, and analyzed the formation mechanism of the NE trending strike-slip faults in the north slope of Tazhong region.The results show that the NE trending strike-slip faults are controlled by the adjustment of pre-existing basement faults and thick mudstone (detachment zone) of the Upper Ordovician, and formed under the action of the surrounding tectonic activities. The NE trending strike-slip faults in Tazhong area experienced two stages of formation and resurrection, and were compressed by paleo-stresses from the southwest and southeast successively.

Abstract： With the help of core observation, thin section identification, well logging identification, and compaction physical simulation experiments, aiming at the scientific problem of the vertical evolution characteristics of compaction diagenetic fractures in glutenite reservoir, taking the glutenite of Kongdian Formation in Bozhong 19-6 condensate gas field as the anatomical object, comprehensive research was carried out, and the following understandings were obtained: 1）Fractures in the glutenite reservoir of Kongdian Formation in Bozhong 19-6 are generally developed, including inherited fractures and noninherited fractures. Inherited fractures developed earlier and occurred following the original cracks along the clastic particles. Noninherited fractures mainly broke along the feldspar cleavage in the form of conjugate shear fractures. 2）Fractures are more developed in gravel particles than sand particles, and in feldspar particles than quartz particles. The degree of crushed fracture development is proportional to the brittleness index, and inversely proportional to the interstitial content. 3）Three stages of glutenite fracture development zones have been developed vertically during physical modeling, and the second fracture development zone is consistent with the distribution of fractures in the study area, which controls the development of high-quality reservoirs.

A large number of Indosinian granites are widely developed in Guide basin, Qinghai Province, but there is a lack of research on their geochemical characteristics, petrogenesis and origin of granites. The resolution of these problems is very important to resolve formation background of indosinian granites in West Qinling. Therefore, LA-ICP-MS zircon U-Pb dating, whole-rock geochemistry and Lu-Hf isotope analysis of granodiorite from drilling hole ZR2 from Zhacanggou area, Guide basin were selected as research objects. Zircon U-Pb isotopic dating results show that the emplacement age of granodiorite is (225.3 ± 1.3) Ma, which is the characteristic of Late Triassic magmatic activity. Characteristics of major and trace elements show that granodiorite is a weak peraluminous, high-K calc-alkaline series rock, showing moderate Eu negative anomalies (δEu=0.59-0.91), enrichment of large ion lithophile elements (Rb, U) and depletion of high field strength elements (Nb,Ta,Ti). Zircon Hf isotopic composition shows that the εHf(t) values of granodiorite range from -7.70 to 0.22, and the corresponding two-stage model ages (TDM2) range from 1 747 to 1 243 Ma, indicating that the granodiorites in Zhacanggou area of Guide basin are the products of melting and mixing of lower crust and lithospheric mantle. Combined with the previous research results, it is considered that the granodiorite in the study area is a transitional tectonic system from syn-collision to post-collision extension after the closure of A’nimaqing-Mianlue Ocean.

The Bojitian gold deposit in southwestern Guizhou Province is located in the eastern section of the Huijiabao anticlinal ore field, and is a nearly super-large Carlin-type gold deposit discovered in recent years. In this paper, the breccia in the Zaofanshan ore section developed in Bojitian gold mining area was taken as the research object. Through detailed drill core observations and combined with the previous basic geological information of the mining area, we analyzed the occurrence and petrological characteristics of the breccia and their relationship with mineralization. Research shows that Zaofanshan breccia is a tectonic breccia and can be divided into two types: Tectonic hydrothermal breccia and tectonic crackle breccia. The ore-forming stages of the deposit include three stages: Quartz-dolomite,  natural gold-pyrite-arsenopyrite, and  orpiment and realgar-cinnabar-quartz-calcite. The ore-forming process of the Bojitian gold deposit is summarized as the formation of the Huijiabao anticline first, the formation of the Zaofanshan ore-bearing tectonic breccias, and finally the migration of ore-bearing hydrothermal fluids, the extraction of metallogenic materials and the formation of ore bodies. The metallogenic model of  “two rich and two poor”  in Bojitian gold deposit is constructed: The closer to the center zone of the Zaofanshan tectonic breccia pipe, the richer the orebody is, and the farther away from the central zone of the tectonic breccia pipe, the poorer the orebody is; The orebodies produced in the deep position of breccia pipe and on its both sides are richer, the orebodies produced in the upper position of breccia pipe and on its both sides are poorer.

In order to explore the impact of human activities on the habitats within the ecological conservation redline, improve the supervision ability of the ecological conservation redline and provide scientific support for improving the supervisory system of the ecological edprotection red line. Taking Zhenlai County of Jilin Province as an example, the high-resolution remote sensing images and related human activity data were used to assess the habitat risk of the area of ecological conservation redline form grid scale based on InVEST model and the spatial analysis capability of GIS. The results showed that: The total habitat risk value in the study area ranges from 0.00 to 1.32. High, medium and low habitat risk areas respectively accounted for 2.31%, 3.26% and 22.12% of the ecological conservation redline area. The impact of human activities disturbance on the habitat in the entire assessment area was dominated by low habitat risk. Among various habitats, the average habitat risk value of forest land was the highest, among which the average habitat risk values of arbor forest land, shrub forest land and other forest land were 0.58, 0.88 and 0.79 respectively, and the highest habitat risk value (shrub forest land) also appeared in the forest land habitat. Compared with other human activities, the cumulative habitat risk values and average habitat risk values of urban village and industrial and mining land were the highest, which were 2 933 161.90 and 1.24 respectively, followed by highway land, which were 1 086 264.68 and 1.19 respectively. Human activities such as dryland, paddy field and fishery had limited impacts on the habitat.

The Songnan gas field is mainly composed of compacted volcanic reservoir with low permeability. According to the gas testing results of the Yingcheng Formation, and other data such as porosity, permeability and impedance, a reservoir classification standard was established. Based on the observation of core, thin sections and SEM, developing patterns of vesicle and fissure in four types of reservoirs have been studied. In addition, potential target reservoirs have been described and evaluated. The reservoir in Songnan gas field can be divided into four types:Type I is high yield without fracturing operation. Type II is high yield after fracturing operation. Type III is no yields before fracturing operation. Type IV is dense layer. Vesicle-fissure pattern corresponding to each reservoir type has been described. Reservoir I presents primary vesicle-microfissure reservoir pattern. Reservoir II presents secondary vesicle-microfissure reservoir pattern. Reservoir III presents primary vesicle-tectonic fissure reservoir pattern. Reservoir IV presents secondary vesicle-tectonic fissure reservoir pattern. Potential evaluation indicated that the No.2 and No.3 targets in YS1 fault block have great potential for development. This study will benefit the analysis of exploiting potentialities, and the reservoir classification standard is more suitable for the actual production situation of dense volcanic reservoir in this area.

Hot dry rock (HDR) is a kind of high temperature rock in depth without or with a small amount of water. A conservative estimation of the HDR thermal energy in the earth's crust (depth of 3-10 km) is equivalent to the 30 times of the total energy contained in the oil, gas and coal all over the world. Enhanced geothermal system (EGS) is an engineered reservoirs that has been created to extract economical amounts of heat from low permeability and/or porosity geothermal resources. The history of study and development of EGS has been about 40 years, but only a small number of countries in the world have conducted EGS research and demonstration, such as the United States, Britain, France, Japan, Australia, etc. In recent years, we have started the research and development. Currently, the exploitation of HDR faces many challenges, such as the creation of the massive artificial fractured thermal reservoir, and implementing EGS commercialization needs further research and technological development. This paper reviewed the experiences and lessons learned from international typical EGS demonstration projects, and discussed the research progress of China in recent years. The purpose of the paper is to offer reference for future scientific research and field demonstration of the EGS in China.

In this paper, the authors review the history of grain size analysis, summarize the commonly used grain size types, introduce the grain size standards and the five grain size analysis methods usually used in sedimentology at present, and give a detailed classification of sedimentation method, field interference analysis method and image method. In addition, the scope of application, the principle of measurement, the advantages and disadvantages of each grain size analysis method are also introduced in detail. Of them,direct measurement method is simple, but poor in accuracy; Sieving analysis is common, but can only precede loose or weakly cemented sediments and cannot reflect grain shape; Sedimentation method is suitable for the analysis of loose samples, weak cemented samples and liquid samples, and can measure fine grained sediments such as fine sand, silt and mud; Field interference method is mainly based on the diffraction, scattering and voltage impulse response of detritus grains, both solid and liquid samples, with high accuracy, and wide applicability; Image method is diverse, simple and intuitive, and strongly operable. In general, in the next few decades, these grain size analysis methods will still co-exist with old and new technologies.

Geothermal energy exploitation and utilization are closely related to groundwater transport and the evolution of water environment. In this study, wereviewed the development status and typical mining technologies for the shallow geothermal energy stored in the soil and phreatic aquifers, median-to-high-temperature geothermal energy in deep aquifers, and high-temperature geothermal energy stored in the hot dry rocks for informational purposes of sustainable development and utilization of large-scale geothermal resources. In particular, the shallow geothermal energy can be classified into ground source heat pump and ground water heat pump according to the subsurface heat source; Median-to-high-temperature geothermal energy can be exploited mainly by direct mining, combination of production and injection and standing column well system; And high-temperature geothermal energy can be exploited using enhanced geothermal systems (EGS) through reservoir reconstruction technique such as hydraulic fracturing or chemical stimulation. Furthermore, the potential impact of geothermal energy exploitation on the groundwater resources was analyzed and summarized following the reported site cases, mainly focused on the cold and heat accumulation brought by heat pump technology, the decline of groundwater level caused by hydrothermal exploitation and the possibility of microseismic events or fracturing fluid leakage caused by hydraulic fracturing of hot dry rocks. In the end, the approaches were proposed to promote the sustainable development of geothermal resources and reduce the negative impacts on groundwater resources, including improving the recharge capacity, maintaining the water balance in the process of mining and irrigation, maintaining the heat exchange efficiency and the re-balance of underground heat, and adopting new materials. 

With the discovery of more and more polymetallic nodule mineralization zones in the South China Sea (SCS) in recent years, the researches of marine polymetallic nodules in this area have become deeper. The SCS marginal-sea polymetallic nodules have their own unique characteristics, which are very different from those in the oceanic environment. Based on the comparative analysis of the previous research results, the authors studied the metallogenetic characteristics of the SCS polymetallic nodules, and provided theoretical guidance for the evaluation of the SCS submarine polymetallic mineral resources. The results show that the mineral composition of the SCS marginal nodules is basically similar to that of oceanic nodules, mainly composed of Mn-and Fe-phase minerals, but the SCS nodules contain a large amount of silicate minerals, indicating that they are greatly affected by terrestrial detrital minerals. Compared to the oceanic nodules in the main economic mineralization zones, the content of the main economic elements such as Mn, Cu, Co, Ni and Zn in the SCS nodules are relatively low, while the contents of terrestrial-derived elements such as Fe, Ti, P, Nb, Pb, Rb, Sc, Ta, Sr, Th and REY (REE and Y) are relatively high. The elemental geochemical characteristics and REE shale-normalized patterns of the SCS polymetallic nodules show that they are of hydrogenetic origin with lower Mn/Fe ratios, high average growth rate, and relatively higher positive δCe anomalies, indicating that the SCS nodules grew in more oxidizing seawater environment. Although the high sediment accumulation rate and turbulent seawater environment affect the mineralization of the SCS nodules, the entry of a large number of terrestrial material provides a rich source of metallogenetic material for the rapid growth of nodules. The SCS marginal polymetallic nodules are rich in a variety of economic metal elements, and can be used as potential marine mineral resources.

Target detection is a fundamental and routine task in remote sensing image processing. In this paper, we design a target detection algorithm for remote sensing images based on the YOLOX network. Firstly, ASFF is added to the feature extraction module PANet to deeply mine the fine features with inconsistent scale in target detection. Secondly, an ECA-based feature extraction module is designed with efficient channel interaction to reduce the complexity of the model while paying more attention to the positive sample feature information in the feature map. Then, to avoid the problem of gradient disappearance and weak activation effect caused by overfitting, the use of swish activation function is proposed. Finally, experiments are conducted on DOTA to verify the best mechanism and effectiveness of the improved method through qualitative analyses of the ablation experiments and quantitative comparison experiments. With the addition of ASFF and ECA mechanisms and the optimization of the swish activation function, the improved network model achieves an mAP of 74.42%, an improvement of 12.75% over the original network. Compared with the current widely used target detection algorithms Mobilenet-YOLOv4, YOLOv4, YOLOv5 and YOLOX, the proposed  algorithm achieves an improvement of 11.42%-17.84% in mAP accuracy.

The authors analyze and discuss the modeling technique of 3D geomodeling in the process of numerical reservoir simulation, introduces the detailed modeling method based on corner-point grids model and gives the corresponding implementation steps. The main process is to:construct the fault model according to the fault data;bulid the pillar gridding model based on the fault model;complete the layer which bares the fault based on the pillar gridding skeleton model through, adopting the layer recovery technique to complete the layer that contains fault; and further, accomplish the building of the property model according to the interpolation of physical property parameters based on the structural model. Finally, by takeing the fractured-vuggy reservoir of Tahe oilfield as an example, we validate the modeling process and technology.

Microseismic positioning method is a core technology in the field of microseismic monitoring, and the criterion to consider the application effect of microseismic technology lies in the accuracy of the source positioning method. Given the application of unconventional oil and gas development in microseismic positioning, the authors expound on the microseismic positioning methods. Among them, the geometric mapping method has the advantages of robustness and high efficiency, but its positioning accuracy is low when the source location is deep; the linear positioning method does not need the accuracy of the velocity model, but has a great impact on the accuracy of first break pick-up; the nonlinear positioning method is more sensitive to first break picking and requires higher accuracy of the velocity model, but the calculation is small; the hybrid positioning method improves the positioning accuracy and efficiency to a certain extent, but the advantages are not obvious when the signal-to-noise ratio is low,and the speed model precision is not high; the positioning method based on waveform migration does not need to consider the precision of first break pick-up, but the calculation is large; the positioning method based on neural network using training network training is highly accurate, and the error is small. The authors also discuss the application of multi-method and multi-parameter information fusion technology in microseismic location of oil and gas reservoir.

Since the great potential of Precambrian-Cambrian strata for oil and gas exploration in the central and western of China has been discovered, it had attracted widespread attention recent years. In this paper, the petroleum geological characteristics and main control factors for the hydrocarbon accumulation of the typical Precambrian-Cambrian basins are described, taking the Oman basin and East Siberian basin for example. We expect to provide a meaningful reference for the oil and gas exploration breakthrough in Precambrian-Cambrian basins of China. The source rocks of Oman basin and East Siberian basin both developed in the initial rifting area, which have generated lots of hydrocarbons before Silurian or Devonian under the control of depth. Sandstone distributed widely as the main reservoir lithology, which can be transformed into high-quality regional reservoirs by post-reformation impacts, such as weathering, leaching, cement dissolution and tectonic fractures.The cumulative thickness of gypsum-salt strata is more than 1 000 m, which is the key factor of the regional seal to preserve the ancient reservoirs generated from the Precambrian-Cambrian stratum, after compared with the petroleum geological characteristics of the other Precambrian-Cambrian basins, we can find that Tarim basin Cambrian petroleum system also has the characteristics of an ancient giant fields, which mainly includes the development of several sets of high abundance of high-quality hydrocarbon source rocks, a thick layer of rock salt paste regional cap and accumulation hydrocarbon in multiple depths after long-distance migration. These indicate that the Tarim basin Cambrian has huge oil and gas exploration potential.

It is difficult to represent the multi-scale structure feature of rocks by using a single resolution digital core model. Through taking a sandstone sample, by means of core multi-resolution CT imaging,the accurate matching of core images with different resolutions is realized by the feature based image registration method. The multi-scale and -component digital core model is constructed along with the segmentation of pores and minerals in the registered images based on image fusion. The results show that the multi-scale and -component digital core model could represent the cross scale pore structures; and the pore distribution agrees with the results from NMR. The mineral contents of digital core are more consistent with the results from XRD than that from Qemscan. The multi-scale and -component digital core model factually restores the structure features of all rock components.

By using the independently developed high-temperature/high-pressure reactor,CO₂ water solubility has been tested under different temperatures,pressures and salinities. The results show that the water solubility of CO₂ increases with pressure under a certain temperature, while it declines with the increase of temperature under a certain pressure. However, when temperature is above 100℃ and pressure is around 22 MPa,the solubility is prone to decrease with increasing temperature under a low pressure (less than 22 MPa) and the solubility is prone to slightly increase with increasing temperature under a high pressure(greater than 22 MPa). Besides, under a certain temperature and pressure,CO₂ water solubility decreases with the increase of water salinity. On the basis of measured and existing data, a new model has been built to calculate CO₂ water solubility precisely by modifying the parameters of PR-HV EOS. In comparison to other models, its accuracy is higher with an average relative error of 2.69%.

Two 80 meters deep boreholes (BT113 and BT114) were carried in the west coast of Bohai Bay in order to clarify the revolution of sedimentary environments. Three marine sedimentary beds were identified based on sediment composition and texture, faunal assemblages (mollusk, benthic foraminifera and ostracoda) as well as AMS ¹⁴C and OSL ages. According to their order, from bottom to top, they are interpreted as Marine Bed 3 (M3) deposited in the Later Mid-Pleistocene, Marine Bed 2 (M2) in the Late Pleistocene and Marine Bed 1 (M1) in the Holocene. These marine beds, from M3 to M1, reveal three major sea level movements since the Late Mid-Pleistocene. M3, M2 and M1, corresponding to marine facies deposited in MIS (marine isotope stage) 7, MIS5, and MIS1, respectively, indicate the repeated highstands during those periods. Therefore, it can be conclude that the development of these marine beds recording the regional sea level trends in the west coast of Bohai Bay, is well accordant with the global change. Different from the previous studies, authors consider that the marine transgression which controlled sea water to intrude into the Bohai Sea did not impact the studied area during MIS3 due to the relative lowstand and shallow topography of Bohai Strait. Contrastive analysis of multi boreholes indicates that the three marine beds are distributed widely and comparable well in the west coast of Bohai Bay. Changeable elevation and thickness of the marine beds within different boreholes imply that there have happened differential depressional movements during the Late Pleistocene period.

Copper resources in the Southern and Central Africa are mainly distributed in 12 countries such as Zambia, DR Congo, and South Africa. Based on the study of the formation of African continent, subsequent Neoproterozoic pan-African movement, and Paleozoic-Cenozoic sedimentation, the authors suggest that apart from the northwestern margin of the continent, namely the region from the Morocco to Atlas mountains in Tunisia, the African continent is a grade Ⅰ tectonic unit, and which can be broken down into 5 grade Ⅱ and 28 grade Ⅲ tectonic units by taking the Neoproterozoic pan-African movement as a marker. The 5 gradeⅡtectonic units include the Western African craton, the Eastern African craton, the Central African craton, the Southern African craton, and the pan-African structural belt; on the basis of the above tectonic breakdown, the whole African continent is suggested to be the grade Ⅰ metallogenic domain, and which is divided into 3 grade Ⅱ metallogenic provinces and 32 grade Ⅲ metallogenic regions(belts). 12 of them are related to copper deposits. The 3 metallogenic provinces include Au-Fe-Mn-Cr-Ni-U and diamond metallogenic province in the Southern African craton, Au-Cu-Fe-W-Sn-Nb-Ta and diamond metallogenic province in the Central African craton, and the metallogenic province in pan-African tectonic belt. A preliminary analysis was conducted. Based on the results of geological characteristics and mineralization setting, a summary of the typical ore deposits in the major metallogenic regions (belts) is given in this paper to cover a variety of deposits such as sedimentary metamorphic-reformed Cu-Co deposits, mafic and ultramafic intrusive related Cu-Ni deposits, greenstone belt related copper deposits, carbonate rock related copper deposits, and copper polymetallic deposits associated with limestone. According to the distribution of copper resources, the breakdown of tectonic units, the metallogenic regions (belts), and the characteristics of representative deposits, the authors divide the central and Southern Africa into five potential copper polymetallic ore prospecting areas.

Along with the rapid development of marine economy, ever increasing emphasis has been put on strengthening marine defense security, improving the development of marine resources and protecting the marine ecological environment, the three aspects which complement to each other; and the corresponding effective detection technology, the key to ensure the marine safety and security, the resource development efficiency, and the balance of ecology and real-time monitoring, as well as to prevent pollution, has become a hot research focus in the current ocean related research and engineering field. Based on the unique advantages of optical fiber sensor over traditional electronic and mechanical sensors, this paper gave an introduction to the technology, system design and characteristics of fiber sensing, in the fields including coastal defense and livelihood security, subsea natural disaster prediction, effective exploration of ocean energy, ocean engineering safety monitoring, and marine environment online monitoring.Consquently, the present review aims to promot optical fiber sensing technology in the ocean.

Dayangshu basin is a Late Mesozoic residual basin with a low degree of exploration and research. It shows a good exploration prospect with the industrial oil flows obtained from several wells in recent years in the southern depression. A systematic understanding of the source rocks and the hydrocarbon origin of Jiufengshan Formation is still uncertain. Based on the geochemical analysis data of source rocks and crude oils, including TOC、Rock-Eval、GC-MS, and carbon isotope, the hydrocarbon generation potential of source rocks of Jiufengshan formation are evaluated, the properties of crude oils and oil source are studied. The results show that medium-good source rocks are developed in the first member (K1j1) and the third member(K1j3) of Jiufengshan Formation, with w（TOC） of 1.76% and 2.59%, w（ S1 + S2） of 4.44 mg/g and 7.36 mg/g, bitumen of 0.21% and 0.09% respectively. The organic matter type of the K1j1 is mainly type Ⅱ1 including some typeⅠ, K1j3 is mainly type Ⅱ1 including some typeⅡ2, and the vitrinite reflectance (Ro) of the source rocks in K1j1 is mainly 0.70% to 1.60%, at the mature to high mature evolution stage. Ro in K1j3 is mainly from 0.50% to 1.10% and at the mature evolution stage. The hydrocarbon generation threshold of the source rock is about 1 300 m, and the hydrocarbon generation peak is about 1 750 m. The source rock has the characteristics of early hydrocarbon generation. The crude oils are light to medium, characterized by high viscosity, high wax, low sulfur, and high saturated hydrocarbon. The crude oil enriches light carbon isotope with δ13Coil from -30.40‰ to -29.38‰, δ13C sat from -30.78‰ to -29.07‰, and δ13Caro from -29.73‰ to -27.91‰, which indicates the source of lacustrine algae. The main peaks of alkane in oil are nC19 and nC21, OEP is 1.07 to 1.08, and Pr / Ph is 0.83 to 1.10. The crude oil can be divided into two groups based on terpenoid steroid marker. Group one includes the crude oil of Wells YC1 and Y3, with relatively high tricyclic terpane, C30D, Ts/Tm, C29Ts/C29 hopane, sterane C27R/C29R, regular sterane / hopane, rearranged sterane / regular sterane, C2920S / 20 (S+R), C29ββ/(ββ++αα) and low β-carotene. Group two includes the crude oil of Well YX4 and Well Y6, with high β-carotene and relatively low sterane terpane ratios, indicating that the maturity of Well YC1 and Well Y3 oil is higher than that of Well YX4 and Well Y6, and there are slight differences in sedimentary environment and parent material source. The oil and rock correlation of biomarkers shows that the crude oil of Wells YC1 and Y3 mainly comes from the source rock of K1j1, and the crude oil of YX4 and Y6 wells mainly comes from the source rock of K1j3. The potential hydrocarbon accumulations in this area are source-reservoir integrated accumulations and lower source rocks generation-upward migration accumulations.

The effect of the traditional groundwater level prediction model is not ideal due to the lack of considering the temporal and spatial variation rules and the relevant influencing factors of groundwater level.The authors used the long and short term memory neural network (LSTM), adopted the method of multivariable input,and constructed the groundwater level prediction model. Taking the monitoring Well J1 in Daiyue district of Tai'an City as an example, the groundwater level dynamic monitoring data from 2001 to 2014 and the relevant influencing factor data were used to predict the groundwater level from 2015 to 2016 by using the multivariable LSTM neural network, and further compared with the single variable LSTM neural network model and BP neural network model. The research results show that the BP neural network prediction model can only make the corresponding prediction according to the change of the influencing variables without considering the change rule of timing sequence, so the prediction error is large (2.399 3). The single-variable LSTM model only takes the groundwater level as the variable input with no considering the influence of relevant factors, and the prediction error is 2.102 2. The prediction accuracy of the LSTM neural network prediction model based on multivariable input is significantly higher than that of the univariate LSTM neural network and BP neural network models, and the prediction root mean square error is only 1.919 1, which successfully verifies the accuracy of the multivariable LSTM neural network groundwater level prediction model.

Supraglacial lake is an important part of the ice sheet hydrological system, which can reflect the characteristics of ice sheet surface meltwater and influence the polar climate and environmental changes. In this paper, a fine extraction method of the supraglacial lake by spectral information and morphology information in northern Greenland is proposed based on WorldView-2 images. Firstly, the ice surface water was segmented from ice with index of water body suitable for ice environment NDWIice and threshold. Then, the ice surface water is divided into three types: Independent supraglacial lake, independent supraglacial runoff and mixed area, by morphological rules. Finally, Fourier descriptor-assisted watershed algorithm is introduced to extract the ice lake. In order to verify the feasibility of the method, WorldView-2 image sequences of nine periods in one ablation period were selected for experiment. Compared with other automated methods and manual digitalization results, the extraction accuracy and integrity of the proposed method are higher than 90%, and the average error rate is lower than 0.2%, which shows obvious advantages.

The Jianbian farm area in Heilongjiang Province is located at the intersection of the Great and Lesser Xing’an Ranges. The multi-stage magmatic and tectonic evolution history in this area has resulted in a complex and diverse geological background for mineralization. Based on the interpretation of Landsat ETM image data in the Jianbian farm area of Heilongjiang, this paper combined the mineral spectral characteristics and the basic geological data, and used the method system of “de-interference, principal component analysis, and ratio method combined with anomaly screening” to extract the mineralized alteration information, such as iron staining and hydroxylation in the study area. Thirteen hydroxyl mineralization alteration anomalies and seventeen iron-stained mineralization alteration anomalies were identified. The mineralized alteration anomalies were mainly found in Cretaceous volcanic strata and were mainly distributed along the intersection of NE- and NW-trending faults, NNW- and SN-trending faults. They were closely related to the contact zone of Mesozoic volcanic rocks and Early Cretaceous-Early Carboniferous intrusive rocks. Combining the known geological and mineral data and field verification results, it is found that iron-stained anomalous minerals such as limonite and hematite, as well as anomalous hydroxyl minerals such as carbonation and chloritization, were commonly developed in this area. The extracted iron-stained and hydroxyl mineralized alteration anomalies closely matched physical and chemical exploration anomalies, and were highly consistent with known Au, Cu and Mo occurrences and mineralized occurrences. This provides a theoretical basis and direction for the next step of mineral exploration in the study area.

There are numerous Late Paleozoic acidic intrusive rocks in Wenquan area, which is located on the northern margin of the Yili block. In this paper, we present new zircon U-Pb geochronology, Lu-Hf isotopic and geochemical studies of the Early Devonian granites from Wenquan area, aiming to confirm their timing, discuss their petrogenesis, and explore their tectonic evolution process. The zircon LA-ICP-MS U-Pb age of the monzogranites is (418±7) Ma which indicates that their crystallization age is the product of Early Devonian magmatic activity. Meanwhile, the zircon Hf isotope compositions of the monzogranite are typically characterized by high εHf(t) values (8.2-14.0, with an average of 11.3), and the young two-stage model ages (TDM2=863-492 Ma), implying their derivation from a relatively juvenile crust. These two types of granites are characterized by high SiO2, weakly peraluminous, as well as low CaO and MgO contents. The trace elements of the granites are characterized by depletion in high field strength elements (Nb, Ti, P), and enrichment in large ion lithophile elements (K, Rb). The standardized distribution pattern of rare earth elements in chondrites is enriched in light rare earth elements and depleted in heavy rare earth elements, with significant negative Eu anomalies. The low zircon saturation temperature, negative correlation between P2O5 and SiO2, and other geochemical features suggest the granites are I-type granites. Several tectonic discrimination diagrams shows that they were formed in a continental magmatic arc setting. Combined with the regional tectonic background and the evolution information of magmatic rocks in the adjacent area, it is speculated that the granites were mainly derived from the crustal accretion in response to subduction of the Junggar-Balkhash Ocean. 

The characteristics of conventional logging curves under different fracture scales were analyzed, the logging curve classification methods of Class Ⅰ (well diameter expansion ratio >18%, deep resistivity < 20 Ω·m, interval transit time >260 μs/m, density <2.4 g/cm3), Class Ⅱ(well diameter slightly expanded, deep resistivity <30 Ω·m, interval transit time > 235 μs/m, density < 2.55 g/cm3), and Class Ⅲ (no significant changes in well diameter expansion, deep resistivity, interval transit time and density) fracture scales were established, and the fuzzy identification sample space was constructed on the basis of considering the fracture scale, and the membership degree function and equation of whether the reservoir capacity of the extended formation of Honghe oilfield was low or high production was determined. If the low yield degree of membership is greater than or equal to the high yield degree of membership, it is a low yield oil layer, otherwise it is a high yield oil layer.After the identification verification of 20 oil layers, the accuracy rate of this model is 85%, and a good identification effect has been achieved.

A geological disaster induced by reservoir impoundment is common. It is important to study the characteristics and stability of deposit slope at reservoir bank before and after impoundment for prevention of such a disaster. Based on the in-situ detailed engineering geological investigation and monitoring materials, the structural and deformation characteristics of deposit slope were analyzed, and the formation and deformation mechanisms were discussed in this study. Finally, based on the discrete element method, the stability of this slope was evaluated. Based on the above research results, the deposit slope was formed from the ancient slide, and the reservoir water level raised by nearly 40m in two months, thus activating the ancient landslides and resulting in the deformation. The engineering treatment such as drainage tunnels and drainage holes slow down the deformation of the slope dramatically, and the deformation of some observation points has a convergence trend.