By the aid of the international mining software SURPAC, a geologic database for a multi-metal mine was established, 3D models of the surface, geologic fault, ore body, cavity and the underground openings were built, a...By the aid of the international mining software SURPAC, a geologic database for a multi-metal mine was established, 3D models of the surface, geologic fault, ore body, cavity and the underground openings were built, and the volume of the cavity of the mine based on the cavity 3D model was calculated. In order to compute the reserves, a grade block model was built and each metal element grade was estimated using Ordinary Kriging. Then, the reserve of each metal element and every sublevel of the mine was worked out. Finally, the calculated result of each metal reserve to its actual prospecting reserve was compared, and the results show that they are all almost equal to each other. The absolute errors of Sn, Pb, and Zn reserves are only 1.45%, 1.59% and 1.62%, respectively. Obviously, the built models are reliable and the calculated results of reserves are correct. They can be used to assist the geologic and mining engineers of the mine to do research work of reserves estimation, mining design, plan making and so on.展开更多
The onshore oil and gas exploration has stepped into a new stage in China, with equal attention paid to both stratigraphic and subtle reservoirs and structural reservoirs. In the past few years, the increases in oil r...The onshore oil and gas exploration has stepped into a new stage in China, with equal attention paid to both stratigraphic and subtle reservoirs and structural reservoirs. In the past few years, the increases in oil reserves in most basins were found mainly in the stratigraphic and subtle reservoirs. Latest resource evaluation shows that the onshore stratigraphic and subtle reservoirs in China account for 42% of the total remaining resource, the highest in the four major exploration regions. Therefore, these reservoirs will be the most practical, potential and prevalent fields for long-lasting oil and gas exploration in onshore China. Among PetroChina's annual oil geologic reserves of 4.3 × 108t^4.6× 108t, the stratigraphic and subtle reservoirs account for more than 50%. In such basins as Songliao, Ordos, Bohai Bay, Junggar, Tarim, Sichuan and Erlian basins, stratigraphic and subtle reservoirs with geologic reserves ranging from 5×107t to 3×108t were discovered, including Ansai, Jing'an, Daqingzijing, Liuxi, well-21 area in Shinan, and Hadexun. Stratigraphic and subtle reservoirs in the four types of inland basins differ from each other in the formation conditions and the distribution patterns. While continental basins are controlled by unconformity surface, maximum flooding surface and fracture surface, the Paleozoic marine basins are influenced by paleouplift, unconformity surface, and fluctuation of the sea level. Through exploration practices and research, PetroChina has formed its own technique series focused on 3-D seismics and sequence stratigraphy.展开更多
This study analyses the geological characteristics and development progress of unconventional gas in China,summarizes the development theories and technologies,discusses the prospects and challenges of unconventional ...This study analyses the geological characteristics and development progress of unconventional gas in China,summarizes the development theories and technologies,discusses the prospects and challenges of unconventional gas development,and puts forward the future trends of development technologies.Various technologies of unconventional gas development are available in China.Shale gas development technologies include comprehensive geological evaluation,volume fracturing of cluster horizontal wells under complex stress conditions,and factory-like operation of horizontal wells in complex mountainous area et al.Tight gas development technologies include fluid identification and quantitative prediction,optimization of well patterns,multi-layer fracturing in vertical well,staged fracturing in horizontal well,and drainage gas recovery.Coalbed methane(CBM)development technologies include the prediction of medium-high-and medium-low-rank CBM enrichment areas,rate-variable hydraulic fracturing,and quantitative drainage recovery with five stages,three pressures,and four controls.For economic and effective development of unconventional gas,further efforts should be made.First,intensified studies should be conducted on high-precision prediction and fine characterization technologies of high-quality shale reservoirs in deep marine,continental,and transitional facies.Second,key theories and technologies such as fast drilling and completion of wells with long laterals as well as large-scale volume fracturing should be developed to improve well productivity.Third,new technologies such as multiple well-type development,fluid injection,and nano-flooding should be developed to enhance the recovery.Fourth,effort should be made to identify the accumulation mechanism and large-scale effective development technologies for CBM.Fifth,the application of large amounts of data and artificial intelligence in the entire process of unconventional gas development should be considered to reduce the development cost.展开更多
Geological radar probing technology finds wide application in engineering projects. The high-precision characteristics of geologic radar should be studied in connection with fine processing and interpretation. This ar...Geological radar probing technology finds wide application in engineering projects. The high-precision characteristics of geologic radar should be studied in connection with fine processing and interpretation. This article discusses such issues as (1) geologic radar noise source and (2) fine processing and interpretation of radar data. It is focused on how to achieve fine processing and interpretation.展开更多
The Fuling shale gas field in China is the largest shale gas field as well as the largest of its type discovered in any Lower Paleozoic formation.In this study,the geology and production of the upper and lower gas lay...The Fuling shale gas field in China is the largest shale gas field as well as the largest of its type discovered in any Lower Paleozoic formation.In this study,the geology and production of the upper and lower gas layers in the Fuling shale gas field are evaluated in terms of structure,shale quality,fault,initial production,and estimated ultimate recovery(EUR).The shale in the lower gas layer of the Jiaoshiba anticline is a high-quality reservoir,where the space is dominated by organic pores in kerogen,and the gas content is high.The shale gas wells reveal relatively high initial production and EUR.However,the shale in the upper gas layer of the Jiaoshiba anticline has reservoir space mainly composed of clay mineral pores and organic pores within bitumen,and the gas content is low.In terms of structure,primary gas migration may occur in the upper gas layer,resulting in free gas accumulation in the structural high,where the development effects are generally better than those in the structural low.The lower gas layer in the Pingqiao anticline,is the main interval for shale gas accumulation and development due to the high-quality shale.Under the influence of faults,the efficiency of exploration wells emplaced on top of the anticline is much lower a compared with those in the flanks.The residual synclines close to the Sichuan Basin,including the Baima and Baitao anticlines,are characterized by more recent uplifts,larger area,greater distance from the deep and large faults,and early fracture closure.Therefore,we recommend that the shale gas exploration and development should be carried out preferentially in areas close to the center of the residual synclines,featuring relatively high-pressure coefficient and moderate burial depth.展开更多
Understanding hydrocarbon migration and accumulation mechanisms is one of the key scientif ic problems that should be solved for effective hydrocarbon exploration in the superimposed basins developed in northwest Chin...Understanding hydrocarbon migration and accumulation mechanisms is one of the key scientif ic problems that should be solved for effective hydrocarbon exploration in the superimposed basins developed in northwest China. The northwest striking No.1 slope break zone, which is a representative of superimposed basins in the Tarim Basin, can be divided into five parts due to the intersection of the northeast strike-slip faults. Controlled by the tectonic framework, the types and properties of reservoirs and the hydrocarbon compositions can also be divided into five parts from east to west. Anomalies of all the parameters were found on the fault intersection zone and weakened up-dip along the structural ridge away from it. Thus, it can be inferred that the intersection zone is the hydrocarbon charging position. This new conclusion differs greatly from the traditional viewpoint, which believes that the hydrocarbon migrates and accumulates along the whole plane of the No.1 slope break zone. The viewpoint is further supported by the evidence from the theory of main pathway systems, obvious improvement of the reservoir quality （2-3 orders of magnitude at the intersection zone） and the formation mechanisms of the fault intersection zone. Differential hydrocarbon migration and entrapment exists in and around the strike- slip faults. This is controlled by the internal structure of faults. It is concluded that the more complicated the fault structure is, the more significant the effects will be. If there is a deformation band, it will hinder the cross fault migration due to the common feature of two to four orders of magnitude reduction in permeability. Otherwise, hydrocarbons tend to accumulate in the up-dip structure under the control of buoyancy. Further research on the internal fault structure should be emphasized.展开更多
Volcanic rocks are distributed widely in China, which are important exploration targets. By analyzing many discovered volcanic hydrocarbon reservoirs all over the world, the authors summarized the geologic characteris...Volcanic rocks are distributed widely in China, which are important exploration targets. By analyzing many discovered volcanic hydrocarbon reservoirs all over the world, the authors summarized the geologic characteristics of the formation of volcanic hydrocarbon reservoirs in China, and gave further exploration directions and advices. （1） There are mainly Carboniferous-Permian, Jurassic-Cretaceous, Paleogene-Neogene volcanic rocks in oil- and gas-bearing basins in China, which are mainly distributed in the Junggar Basin, Songliao Basin, Bohai Bay Basin, etc. There are mainly intermediate rocks and acidic rocks in east China, and intermediate rocks and basic rocks in west China. They primarily develop in intracontinentai rift settings and island arc environments. （2） Porefissure reservoirs are distributed widely in basins, which are volcanic rocks mainly in explosive and effusive facies. （3） Volcanic hydrocarbon reservoirs are chiefly near-source lithostratigraphic hydrocarbon reservoirs, and the oil and gas accumulation is predominantly controlled by lithotypes, faults and structural positions. （4） Deep-seated oil and gas reservoirs in the Songliao Basin and Carboniferous volcanic hydrocarbon reservoirs in the Junggar Basin are potential giant volcanic gas provinces, the volcanic hydrocarbon reservoirs in the Bohai Bay Basin and Santanghu Basin are favorable for oil and gas reserves increase, and volcanic rocks in the Turpan Basin, Sichuan Basin, Tarim Basin have exploration potentiality. （5） The technology series of oil and gas exploration in volcanic rocks have been preliminarily formed.展开更多
Studying the geologic architecture of the Xiong'an New Area will provide important basis for the evaluation of crustal stability, urban planning and infrastructural projects in this region, and it is also of great...Studying the geologic architecture of the Xiong'an New Area will provide important basis for the evaluation of crustal stability, urban planning and infrastructural projects in this region, and it is also of great significance in exploring the occurrence of oil and gas, geothermal, hot dry rock and other resources. The stratigraphic system of the study area is established by using latest high quality seismic reflection and deep borehole data. Characteristics of the major faults developed in the study area are finely depicted with the method of structural analysis. Tectonic evolution of Xiong'an and adjacent areas is reconstructed by using balanced geological cross-section technique. The tectonic activity of the study area is discussed on the basis of the development of secondary faults and the distribution of active earthquakes across the region. This study demonstrates that Xiong'an New Area is located at the transfer zone of the central and northern Jizhong Depression. There are three regional unconformities developed in this area, by which four structural layers are sub-divided. Controlled by the Taihang Mountain piedmont fault, the Daxing fault, the Rongcheng fault and the Niudong fault, the structural framework of the study area is characterized by intervening highs with sags. This structural pattern has an important controlling over the reservoir characteristics, hydrocarbon accumulation and the distribution of geothermal resources and hot dry rock within this region. Rifting in this area began in the early Paleogene, exhibiting typical episodic character and became inactive in Neogene. The development feature of secondary faults along with the distribution of active earthquakes indicate that Xiong'an New Area has been in a relatively stable tectonic setting since the Neogene, while the Baxian Sag and other structural units to the east of it have obviously been in a rather active environment.展开更多
Carbon capture,utilization and storage (CCUS) is considered as a very important technology for mitigating global climate change.Carbon dioxide (CO2) injected into an underground reservoir will induce changes in its ph...Carbon capture,utilization and storage (CCUS) is considered as a very important technology for mitigating global climate change.Carbon dioxide (CO2) injected into an underground reservoir will induce changes in its physical properties and the migration of CO2 will be affected by many factors.Accurately understanding these changes and migration characteristics of CO2 is crucial for selecting a CCUS project site,estimating storage capacity and ensuring storage security.In this paper,the basic principles of nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) technologies are briefly introduced in the context of laboratory experiments related to CCUS.The types of NMR apparatus,experimental samples and testing approaches applied worldwide are discussed and analyzed.Then two typical NMR core analysis systems used in CCUS field and a self-developed high-pressure,low-field NMR rock core flooding experimental system are compared.Finally,a summary of the current deficiencies related to NMR applied to CCUS field is given and future research plans are proposed.展开更多
The objectives of lunar satellite remote sensing are to study lunar surface characteristics, inner structure, and its evolution history. The contents of TiO 2 and FeO are assessed from Clementine UV/VIS data for Sinus...The objectives of lunar satellite remote sensing are to study lunar surface characteristics, inner structure, and its evolution history. The contents of TiO 2 and FeO are assessed from Clementine UV/VIS data for Sinus Iridum. The geologic stratigraphic units and crates are interpreted visually based on SELENE Terrain Camera (TC) images and the spatial resolution of which is up to 10 m. And the geologic ages of different stratigraphic units are calculated by the crater size-frequency distributions measurements. The gravity anomaly is generated from SELENE gravity model (SGM90d) to show its difference from Mare Imbrium. Furthermore, the thickness of lunar regolith is also derived from microwave radiometer data of Chang’e-1 satellite. Integrating these results, it shows that the Sinus Iridum is different from the Mare Imbrium in inner structure and surface sedimentation. And its history of subsidence, deposition, volcanism, and impact is described. It makes sense to the future soft-landing and sampling at potential Sinus Iridum by remote sensing geologic analysis.展开更多
The well LF35-1-1 in the eastern Pearl River Mouth basin （PRMB） of the northern South China Sea revealed unmetamorphosed Middle-Late Jurassic neritic-bathyal sediments and Cretaceous fluvial-lacustrine sediments. Th...The well LF35-1-1 in the eastern Pearl River Mouth basin （PRMB） of the northern South China Sea revealed unmetamorphosed Middle-Late Jurassic neritic-bathyal sediments and Cretaceous fluvial-lacustrine sediments. Three tectonic movements were identified in Late Jurassic to Early Cretaceous, late Early Cretaceous, and Late Cretaceous to Paleocene, respectively. The Late Jurassic marine facies mainly contain the hydrocarbon source and reservoir-seal assemblages, providing a main exploration target.展开更多
Based on the analysis of the basic characteristics of medium-and large-sized marine gas fields in Sichuan Basin, combined with the division of major reservoir forming geological units in the marine craton stage and th...Based on the analysis of the basic characteristics of medium-and large-sized marine gas fields in Sichuan Basin, combined with the division of major reservoir forming geological units in the marine craton stage and their control on key hydrocarbon accumulation factors, the distribution law of medium-and large-sized marine carbonate gas fields in the basin was examined and the exploration direction was pointed out. Through the analysis of the periodic stretching-uplifting background, it is concluded that five large scale paleo-rifts, three large scale paleo-uplifts, five large scale paleo erosion surfaces were formed in the marine craton stage of Sichuan Basin, and these geological units control the key reservoir forming factors of medium and large sized gas fields:(1) Large-scale paleo-rifts control the distribution of high-quality hydrocarbon generation centers.(2) The margin of large-scale paleo-rifts, high position of paleo-uplifts and paleo erosion surfaces control the distribution of high-quality reservoirs.(3) Large-scale paleo-rifts, paleo-uplifts, paleo erosion surfaces and present tectonic setting jointly control the formation of many types of large and medium-sized traps.(4) Natural gas accumulation is controlled by the inheritance evolution of traps in large geological units. Based on the comparative analysis of the distribution characteristics of medium-and large-sized gas fields and large geological units, it is proposed that the superimposition relationship between single or multiple geological units and the present structure controls the distribution of medium-and large-sized gas fields, and the "three paleo" superimposed area is the most advantageous. According to the above rules, the main exploration fields and directions of medium-and large-sized marine carbonate gas fields in Sichuan Basin include periphery of Deyang-Anyue paleo-rift, eastern margin of Longmenshan paleo-rift, margins of Kaijiang-Liangping oceanic trough and Chengkou-western Hubei oceanic trough, the high part of the subaqueous 展开更多
Complex superimposed basins exhibit multi-stage tectonic events and multi-stage reservoir formation; hydrocarbon reservoirs formed in the early stage have generally late-stage genesis characteristics after undergoing ...Complex superimposed basins exhibit multi-stage tectonic events and multi-stage reservoir formation; hydrocarbon reservoirs formed in the early stage have generally late-stage genesis characteristics after undergoing adjustment, reconstruction and destruction of later-stage multiple tectonic events. In this paper, this phenomenon is called the late-stage reservoir formation effect. The late-stage reservoir formation effect is a basic feature of oil and gas-forming reservoirs in complex superimposed basins, revealing not only multi-stage character, relevance and complexity of oil and gas- forming reservoirs in superimposed basins but also the importance of late-stage reservoir formation. Late-stage reservoir formation is not a basic feature of oil and gas forming reservoir in superimposed basins. Multi-stage reservoir formation only characterizes one aspect of oil and gas-forming reservoir in superimposed basins and does not represent fully the complexity of oil and gas-forming reservoir in superimposed basins. We suggest using ＂late-stage reservoir formation effect＂ to replace the ＂late-stage reservoir formation＂ concept to guide the exploration of complex reservoirs in superimposed basins. Under current geologic conditions, the late-stage reservoir formation effect is represented mainly by four basic forms： phase transformation, scale reconstruction, component variation and trap adjustment. The late-stage reservoir formation effect is produced by two kinds of geologic processes： first, the oil and gas retention function of various geologic thresholds （hydrocarbon expulsion threshold, hydrocarbon migration threshold, and hydrocarbon accumulating threshold） causes the actual time of oil and gas reservoir formation to be later than the time of generation of large amounts of hydrocarbon in a conventional sense, producing the late-stage reservoir formation effect; second, multiple types of tectonic events （continuously strong reconstruction, early-stage strong reconstruction, middle-stage strong rec展开更多
Established as a national park in 1887,Banff National Park occupies 2564 square miles(almost 6641 square kilometers)along the eastern slopes of the Rocky Mountains and borders British Columbia.Noted for its beauty,pla...Established as a national park in 1887,Banff National Park occupies 2564 square miles(almost 6641 square kilometers)along the eastern slopes of the Rocky Mountains and borders British Columbia.Noted for its beauty,plant and animal diversity,and ongoing geologic processes,Banff National Park was listed as part of the Canadian Rocky Mountain Parks UNESCO World Heritage site in 1984.展开更多
Based on regional geological setting, stratigraphic distribution and other geological conditions, this paper summarized three types of geothermal reservoirs in the southeast coastal areas of China: Cenozoic sandstone ...Based on regional geological setting, stratigraphic distribution and other geological conditions, this paper summarized three types of geothermal reservoirs in the southeast coastal areas of China: Cenozoic sandstone or sandy conglomerate reservoir, Mesozoic granite fissure reservoir and Paleozoic karst reservoir. Cenozoic sandstone or sandy conglomerate reservoirs are mainly located in Cenozoic basins, such as Zhangzhou, Fuzhou, Sanshui and Leiqiong basins. The Tertiary sedimentary basins such as Leiqiong Basin and Sanshui Basin, are controlled by NE-trending faults, while the Quaternary sedimentary such as Zhangzhou and Fuzhou basins are controlled by NW-trending faults. Mesozoic granite fissure reservoirs are mainly distributed in the southeast coastal areas, such as Zhangzhou, Fuzhou, Fengshun, Yangjiang and southern part of Hainan Province. The distribution of good Mesozoic granite fissure reservoir in these areas is mainly controlled by NE-trending faults. Paleozoic carbonate reservoirs are widely distributed in these areas. Most carbonate rocks are from the upper Paleozoic strata, such as those in the area of Huizhou in Guangdong Province. The major types of geothermal systems in the southeast coastal areas of China belong to medium and low-temperature convection. The geothermal resources developed from the ground to-3 000 m underground could be utilized directly for space heating, greenhouse heating, aquaculture pond heating and industrial uses, as well as other purposes. The geothermal resources with a depth of 3 000~6 000 m underground is mainly featured by Hot Dry Rock(HDR) with a temperature ranges from 150 ℃ to 200 ℃, which is conductive to the development of Enhanced Geothermal System(EGS) and can be utilized for power generation.展开更多
China established Xiong’an New Area in Hebei Province in 2017,which is planned to accommodate about 5 million people,aiming to relieve Beijing City of the functions non-essential to its role as China’s capital and t...China established Xiong’an New Area in Hebei Province in 2017,which is planned to accommodate about 5 million people,aiming to relieve Beijing City of the functions non-essential to its role as China’s capital and to expedite the coordinated development of the Beijing-Tianjin-Hebei region.From 2017 to 2021,the China Geological Survey(CGS)took the lead in multi-factor urban geological surveys involving space,resources,environments,and disasters according to the general requirements of“global vision,international standards,distinctive Chinese features,and future-oriented goals”in Xiong’an New Area,identifying the engineering geologic conditions and geologic environmental challenges of this area.The achievements also include a 3D engineering geological structure model for the whole area,along with“one city proper and five clusters”,insights into the ecology and the background endowment of natural resources like land,geothermal resources,groundwater,and wetland of the area before engineering construction,a comprehensive monitoring network of resources and environments in the area,and the“Transparent Xiong’an”geological information platform that is open,shared,dynamically updated,and three-dimensionally visualized.China’s geologists and urban geology have played a significant role in the urban planning and construction of Xiong’an New Area,providing whole-process geological solutions for urban planning,construction,operation and management.The future urban construction of Xiong’an New Area will necessitate the theoretical and technical support of earth system science(ESS)from various aspects,and the purpose is to enhance the resilience of the new type of city and to provide support for the green,low-carbon,and sustainable development of this area.展开更多
If progress is to be made toward improving geohazard management and emergency decision-making,then lessons need to be learned from past geohazard information.A geologic hazard report provides a useful and reliable sou...If progress is to be made toward improving geohazard management and emergency decision-making,then lessons need to be learned from past geohazard information.A geologic hazard report provides a useful and reliable source of information about the occurrence of an event,along with detailed information about the condition or factors of the geohazard.Analyzing such reports,however,can be a challenging process because these texts are often presented in unstructured long text formats,and contain rich specialized and detailed information.Automatically text classification is commonly used to mine disaster text data in open domains(e.g.,news and microblogs).But it has limitations to performing contextual long-distance dependencies and is insensitive to discourse order.These deficiencies are most obviously exposed in long text fields.Therefore,this paper uses the bidirectional encoder representations from Transformers(BERT),to model long text.Then,utilizing a softmax layer to automatically extract text features and classify geohazards without manual features.The latent Dirichlet allocation(LDA)model is used to examine the interdependencies that exist between causal variables to visualize geohazards.The proposed method is useful in enabling the machine-assisted interpretation of text-based geohazards.Moreover,it can help users visualize causes,processes,and other geohazards and assist decision-makers in emergency responses.展开更多
A geologic time scale is a chronological system that separates the geological strata of a planetary body into different units in temporal sequence and shows its progressive evolution.The time scale of the Moon was est...A geologic time scale is a chronological system that separates the geological strata of a planetary body into different units in temporal sequence and shows its progressive evolution.The time scale of the Moon was established a half-century ago during the telescopic-early Apollo exploration era,using data with limited spatial coverage and resolution.The past decades have seen a wide array of studies,which have significantly extended our understanding of global lunar geologic evolution.Based on a comprehensive review of lunar evolution with respect to the dynamical changes,we propose two major updates to the current lunar time scale paradigm to include the evolution of both endogenic and exogenic dynamic forces now known to have influenced early lunar history.Firstly,based on the temporal interplay of exogenic and endogenic processes in altering the Moon,we defined three Eon/Eonothem-level units to represent three dynamical evolutionary phases.Secondly,the pre-Nectarian System is redefined and divided as the magma ocean-era Magma-oceanian System and the following Aitkenian System beginning with the South Pole-Aitken basin.The ejecta of this basin,Das Formation,was deposited on the primordial lunar crust as the oldest stratum produced from exogenic processes.The updated lunar time scale,facilitated by the post-Apollo exploration and research advances,provides an integrated framework to depict the evolution of the Moon and has important implications for the geologic study of other terrestrial planets.展开更多
基金Project(50490274) supported by the National Natural Science Foundation of China
文摘By the aid of the international mining software SURPAC, a geologic database for a multi-metal mine was established, 3D models of the surface, geologic fault, ore body, cavity and the underground openings were built, and the volume of the cavity of the mine based on the cavity 3D model was calculated. In order to compute the reserves, a grade block model was built and each metal element grade was estimated using Ordinary Kriging. Then, the reserve of each metal element and every sublevel of the mine was worked out. Finally, the calculated result of each metal reserve to its actual prospecting reserve was compared, and the results show that they are all almost equal to each other. The absolute errors of Sn, Pb, and Zn reserves are only 1.45%, 1.59% and 1.62%, respectively. Obviously, the built models are reliable and the calculated results of reserves are correct. They can be used to assist the geologic and mining engineers of the mine to do research work of reserves estimation, mining design, plan making and so on.
文摘The onshore oil and gas exploration has stepped into a new stage in China, with equal attention paid to both stratigraphic and subtle reservoirs and structural reservoirs. In the past few years, the increases in oil reserves in most basins were found mainly in the stratigraphic and subtle reservoirs. Latest resource evaluation shows that the onshore stratigraphic and subtle reservoirs in China account for 42% of the total remaining resource, the highest in the four major exploration regions. Therefore, these reservoirs will be the most practical, potential and prevalent fields for long-lasting oil and gas exploration in onshore China. Among PetroChina's annual oil geologic reserves of 4.3 × 108t^4.6× 108t, the stratigraphic and subtle reservoirs account for more than 50%. In such basins as Songliao, Ordos, Bohai Bay, Junggar, Tarim, Sichuan and Erlian basins, stratigraphic and subtle reservoirs with geologic reserves ranging from 5×107t to 3×108t were discovered, including Ansai, Jing'an, Daqingzijing, Liuxi, well-21 area in Shinan, and Hadexun. Stratigraphic and subtle reservoirs in the four types of inland basins differ from each other in the formation conditions and the distribution patterns. While continental basins are controlled by unconformity surface, maximum flooding surface and fracture surface, the Paleozoic marine basins are influenced by paleouplift, unconformity surface, and fluctuation of the sea level. Through exploration practices and research, PetroChina has formed its own technique series focused on 3-D seismics and sequence stratigraphy.
文摘This study analyses the geological characteristics and development progress of unconventional gas in China,summarizes the development theories and technologies,discusses the prospects and challenges of unconventional gas development,and puts forward the future trends of development technologies.Various technologies of unconventional gas development are available in China.Shale gas development technologies include comprehensive geological evaluation,volume fracturing of cluster horizontal wells under complex stress conditions,and factory-like operation of horizontal wells in complex mountainous area et al.Tight gas development technologies include fluid identification and quantitative prediction,optimization of well patterns,multi-layer fracturing in vertical well,staged fracturing in horizontal well,and drainage gas recovery.Coalbed methane(CBM)development technologies include the prediction of medium-high-and medium-low-rank CBM enrichment areas,rate-variable hydraulic fracturing,and quantitative drainage recovery with five stages,three pressures,and four controls.For economic and effective development of unconventional gas,further efforts should be made.First,intensified studies should be conducted on high-precision prediction and fine characterization technologies of high-quality shale reservoirs in deep marine,continental,and transitional facies.Second,key theories and technologies such as fast drilling and completion of wells with long laterals as well as large-scale volume fracturing should be developed to improve well productivity.Third,new technologies such as multiple well-type development,fluid injection,and nano-flooding should be developed to enhance the recovery.Fourth,effort should be made to identify the accumulation mechanism and large-scale effective development technologies for CBM.Fifth,the application of large amounts of data and artificial intelligence in the entire process of unconventional gas development should be considered to reduce the development cost.
基金This project is sponsored by The Special Fund of Scientific Instruments of National Natural Science Foundation of China(50127402) and The Geophysical Responses to The High-resolution Exploration for Coal-methane of 973 Program(2002CB211707).
文摘Geological radar probing technology finds wide application in engineering projects. The high-precision characteristics of geologic radar should be studied in connection with fine processing and interpretation. This article discusses such issues as (1) geologic radar noise source and (2) fine processing and interpretation of radar data. It is focused on how to achieve fine processing and interpretation.
基金supported by the National Natural Science Foundation of China(Grant No.41872124 and 91755211)and several Sinopec in-house projects.We thank Sinopec Petroleum Exploration and Production Research Institute,Sinopec Exploration Company,Sinopec Jianghan Oilfield,and Sinopec East China Petroleum Company for valuable data and information.
文摘The Fuling shale gas field in China is the largest shale gas field as well as the largest of its type discovered in any Lower Paleozoic formation.In this study,the geology and production of the upper and lower gas layers in the Fuling shale gas field are evaluated in terms of structure,shale quality,fault,initial production,and estimated ultimate recovery(EUR).The shale in the lower gas layer of the Jiaoshiba anticline is a high-quality reservoir,where the space is dominated by organic pores in kerogen,and the gas content is high.The shale gas wells reveal relatively high initial production and EUR.However,the shale in the upper gas layer of the Jiaoshiba anticline has reservoir space mainly composed of clay mineral pores and organic pores within bitumen,and the gas content is low.In terms of structure,primary gas migration may occur in the upper gas layer,resulting in free gas accumulation in the structural high,where the development effects are generally better than those in the structural low.The lower gas layer in the Pingqiao anticline,is the main interval for shale gas accumulation and development due to the high-quality shale.Under the influence of faults,the efficiency of exploration wells emplaced on top of the anticline is much lower a compared with those in the flanks.The residual synclines close to the Sichuan Basin,including the Baima and Baitao anticlines,are characterized by more recent uplifts,larger area,greater distance from the deep and large faults,and early fracture closure.Therefore,we recommend that the shale gas exploration and development should be carried out preferentially in areas close to the center of the residual synclines,featuring relatively high-pressure coefficient and moderate burial depth.
基金supported by the National 973 Basic Research Program (Grant No.2006CB202308)the Major National Science & Technology Program (2008ZX05008-004-012)
文摘Understanding hydrocarbon migration and accumulation mechanisms is one of the key scientif ic problems that should be solved for effective hydrocarbon exploration in the superimposed basins developed in northwest China. The northwest striking No.1 slope break zone, which is a representative of superimposed basins in the Tarim Basin, can be divided into five parts due to the intersection of the northeast strike-slip faults. Controlled by the tectonic framework, the types and properties of reservoirs and the hydrocarbon compositions can also be divided into five parts from east to west. Anomalies of all the parameters were found on the fault intersection zone and weakened up-dip along the structural ridge away from it. Thus, it can be inferred that the intersection zone is the hydrocarbon charging position. This new conclusion differs greatly from the traditional viewpoint, which believes that the hydrocarbon migrates and accumulates along the whole plane of the No.1 slope break zone. The viewpoint is further supported by the evidence from the theory of main pathway systems, obvious improvement of the reservoir quality （2-3 orders of magnitude at the intersection zone） and the formation mechanisms of the fault intersection zone. Differential hydrocarbon migration and entrapment exists in and around the strike- slip faults. This is controlled by the internal structure of faults. It is concluded that the more complicated the fault structure is, the more significant the effects will be. If there is a deformation band, it will hinder the cross fault migration due to the common feature of two to four orders of magnitude reduction in permeability. Otherwise, hydrocarbons tend to accumulate in the up-dip structure under the control of buoyancy. Further research on the internal fault structure should be emphasized.
基金supported by the National Basic Research Program (Grant No. 2009CB219304)Important National Science & Technology Specific Projects (Grant No. 2008ZX05001)supported by exploration and production companies of the CNPC, such as Daqing Oilfield, Jilin Oilfield, and Xinjiang Oilfield. Much help also came from academician Dai Jinxing and others
文摘Volcanic rocks are distributed widely in China, which are important exploration targets. By analyzing many discovered volcanic hydrocarbon reservoirs all over the world, the authors summarized the geologic characteristics of the formation of volcanic hydrocarbon reservoirs in China, and gave further exploration directions and advices. （1） There are mainly Carboniferous-Permian, Jurassic-Cretaceous, Paleogene-Neogene volcanic rocks in oil- and gas-bearing basins in China, which are mainly distributed in the Junggar Basin, Songliao Basin, Bohai Bay Basin, etc. There are mainly intermediate rocks and acidic rocks in east China, and intermediate rocks and basic rocks in west China. They primarily develop in intracontinentai rift settings and island arc environments. （2） Porefissure reservoirs are distributed widely in basins, which are volcanic rocks mainly in explosive and effusive facies. （3） Volcanic hydrocarbon reservoirs are chiefly near-source lithostratigraphic hydrocarbon reservoirs, and the oil and gas accumulation is predominantly controlled by lithotypes, faults and structural positions. （4） Deep-seated oil and gas reservoirs in the Songliao Basin and Carboniferous volcanic hydrocarbon reservoirs in the Junggar Basin are potential giant volcanic gas provinces, the volcanic hydrocarbon reservoirs in the Bohai Bay Basin and Santanghu Basin are favorable for oil and gas reserves increase, and volcanic rocks in the Turpan Basin, Sichuan Basin, Tarim Basin have exploration potentiality. （5） The technology series of oil and gas exploration in volcanic rocks have been preliminarily formed.
基金supported by the National Key Research and Development Program of China (Grant No. 2017YFC0601405)the National Natural Science Foundation of China (Grant No. 41430316)
文摘Studying the geologic architecture of the Xiong'an New Area will provide important basis for the evaluation of crustal stability, urban planning and infrastructural projects in this region, and it is also of great significance in exploring the occurrence of oil and gas, geothermal, hot dry rock and other resources. The stratigraphic system of the study area is established by using latest high quality seismic reflection and deep borehole data. Characteristics of the major faults developed in the study area are finely depicted with the method of structural analysis. Tectonic evolution of Xiong'an and adjacent areas is reconstructed by using balanced geological cross-section technique. The tectonic activity of the study area is discussed on the basis of the development of secondary faults and the distribution of active earthquakes across the region. This study demonstrates that Xiong'an New Area is located at the transfer zone of the central and northern Jizhong Depression. There are three regional unconformities developed in this area, by which four structural layers are sub-divided. Controlled by the Taihang Mountain piedmont fault, the Daxing fault, the Rongcheng fault and the Niudong fault, the structural framework of the study area is characterized by intervening highs with sags. This structural pattern has an important controlling over the reservoir characteristics, hydrocarbon accumulation and the distribution of geothermal resources and hot dry rock within this region. Rifting in this area began in the early Paleogene, exhibiting typical episodic character and became inactive in Neogene. The development feature of secondary faults along with the distribution of active earthquakes indicate that Xiong'an New Area has been in a relatively stable tectonic setting since the Neogene, while the Baxian Sag and other structural units to the east of it have obviously been in a rather active environment.
基金supported by the Open Research Fund of State Key Laboratory of Geomechanics and GeotechnicalEngineering, IRSM, CAS (Grant No. Z017002)the National Natural Science Foundation of China (Grant Nos. 41872210 and 41274111)financial support from the China-Australia Geological Storage of CO_2 (CAGS) Project funded by the Australian Government under the auspices of the China-Australia Joint Coordination Group on Clean Coal Technology
文摘Carbon capture,utilization and storage (CCUS) is considered as a very important technology for mitigating global climate change.Carbon dioxide (CO2) injected into an underground reservoir will induce changes in its physical properties and the migration of CO2 will be affected by many factors.Accurately understanding these changes and migration characteristics of CO2 is crucial for selecting a CCUS project site,estimating storage capacity and ensuring storage security.In this paper,the basic principles of nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) technologies are briefly introduced in the context of laboratory experiments related to CCUS.The types of NMR apparatus,experimental samples and testing approaches applied worldwide are discussed and analyzed.Then two typical NMR core analysis systems used in CCUS field and a self-developed high-pressure,low-field NMR rock core flooding experimental system are compared.Finally,a summary of the current deficiencies related to NMR applied to CCUS field is given and future research plans are proposed.
基金supported by the National Natural Science Foundation of China(Grant Nos. 40901187 and 40901159) the High-Tech Research and Development Programme (Grant Nos. 2008AA12A212, 2010AA122203)
文摘The objectives of lunar satellite remote sensing are to study lunar surface characteristics, inner structure, and its evolution history. The contents of TiO 2 and FeO are assessed from Clementine UV/VIS data for Sinus Iridum. The geologic stratigraphic units and crates are interpreted visually based on SELENE Terrain Camera (TC) images and the spatial resolution of which is up to 10 m. And the geologic ages of different stratigraphic units are calculated by the crater size-frequency distributions measurements. The gravity anomaly is generated from SELENE gravity model (SGM90d) to show its difference from Mare Imbrium. Furthermore, the thickness of lunar regolith is also derived from microwave radiometer data of Chang’e-1 satellite. Integrating these results, it shows that the Sinus Iridum is different from the Mare Imbrium in inner structure and surface sedimentation. And its history of subsidence, deposition, volcanism, and impact is described. It makes sense to the future soft-landing and sampling at potential Sinus Iridum by remote sensing geologic analysis.
基金supported by the National Natural Science Foundation of China (Nos. 40576027, 40238060)
文摘The well LF35-1-1 in the eastern Pearl River Mouth basin （PRMB） of the northern South China Sea revealed unmetamorphosed Middle-Late Jurassic neritic-bathyal sediments and Cretaceous fluvial-lacustrine sediments. Three tectonic movements were identified in Late Jurassic to Early Cretaceous, late Early Cretaceous, and Late Cretaceous to Paleocene, respectively. The Late Jurassic marine facies mainly contain the hydrocarbon source and reservoir-seal assemblages, providing a main exploration target.
基金Supported by the China National Science and Technology Major Project(2016ZX05007004,2016ZX05004005)
文摘Based on the analysis of the basic characteristics of medium-and large-sized marine gas fields in Sichuan Basin, combined with the division of major reservoir forming geological units in the marine craton stage and their control on key hydrocarbon accumulation factors, the distribution law of medium-and large-sized marine carbonate gas fields in the basin was examined and the exploration direction was pointed out. Through the analysis of the periodic stretching-uplifting background, it is concluded that five large scale paleo-rifts, three large scale paleo-uplifts, five large scale paleo erosion surfaces were formed in the marine craton stage of Sichuan Basin, and these geological units control the key reservoir forming factors of medium and large sized gas fields:(1) Large-scale paleo-rifts control the distribution of high-quality hydrocarbon generation centers.(2) The margin of large-scale paleo-rifts, high position of paleo-uplifts and paleo erosion surfaces control the distribution of high-quality reservoirs.(3) Large-scale paleo-rifts, paleo-uplifts, paleo erosion surfaces and present tectonic setting jointly control the formation of many types of large and medium-sized traps.(4) Natural gas accumulation is controlled by the inheritance evolution of traps in large geological units. Based on the comparative analysis of the distribution characteristics of medium-and large-sized gas fields and large geological units, it is proposed that the superimposition relationship between single or multiple geological units and the present structure controls the distribution of medium-and large-sized gas fields, and the "three paleo" superimposed area is the most advantageous. According to the above rules, the main exploration fields and directions of medium-and large-sized marine carbonate gas fields in Sichuan Basin include periphery of Deyang-Anyue paleo-rift, eastern margin of Longmenshan paleo-rift, margins of Kaijiang-Liangping oceanic trough and Chengkou-western Hubei oceanic trough, the high part of the subaqueous
基金State Key Basic Research "973" Program (2006CB202308) for funding this research
文摘Complex superimposed basins exhibit multi-stage tectonic events and multi-stage reservoir formation; hydrocarbon reservoirs formed in the early stage have generally late-stage genesis characteristics after undergoing adjustment, reconstruction and destruction of later-stage multiple tectonic events. In this paper, this phenomenon is called the late-stage reservoir formation effect. The late-stage reservoir formation effect is a basic feature of oil and gas-forming reservoirs in complex superimposed basins, revealing not only multi-stage character, relevance and complexity of oil and gas- forming reservoirs in superimposed basins but also the importance of late-stage reservoir formation. Late-stage reservoir formation is not a basic feature of oil and gas forming reservoir in superimposed basins. Multi-stage reservoir formation only characterizes one aspect of oil and gas-forming reservoir in superimposed basins and does not represent fully the complexity of oil and gas-forming reservoir in superimposed basins. We suggest using ＂late-stage reservoir formation effect＂ to replace the ＂late-stage reservoir formation＂ concept to guide the exploration of complex reservoirs in superimposed basins. Under current geologic conditions, the late-stage reservoir formation effect is represented mainly by four basic forms： phase transformation, scale reconstruction, component variation and trap adjustment. The late-stage reservoir formation effect is produced by two kinds of geologic processes： first, the oil and gas retention function of various geologic thresholds （hydrocarbon expulsion threshold, hydrocarbon migration threshold, and hydrocarbon accumulating threshold） causes the actual time of oil and gas reservoir formation to be later than the time of generation of large amounts of hydrocarbon in a conventional sense, producing the late-stage reservoir formation effect; second, multiple types of tectonic events （continuously strong reconstruction, early-stage strong reconstruction, middle-stage strong rec
文摘Established as a national park in 1887,Banff National Park occupies 2564 square miles(almost 6641 square kilometers)along the eastern slopes of the Rocky Mountains and borders British Columbia.Noted for its beauty,plant and animal diversity,and ongoing geologic processes,Banff National Park was listed as part of the Canadian Rocky Mountain Parks UNESCO World Heritage site in 1984.
基金National Key Research and Development Project (No. 2019YFC0604903)consultation research project of Chinese Academy of Engineering (No. 2019-XZ-35-04)。
文摘Based on regional geological setting, stratigraphic distribution and other geological conditions, this paper summarized three types of geothermal reservoirs in the southeast coastal areas of China: Cenozoic sandstone or sandy conglomerate reservoir, Mesozoic granite fissure reservoir and Paleozoic karst reservoir. Cenozoic sandstone or sandy conglomerate reservoirs are mainly located in Cenozoic basins, such as Zhangzhou, Fuzhou, Sanshui and Leiqiong basins. The Tertiary sedimentary basins such as Leiqiong Basin and Sanshui Basin, are controlled by NE-trending faults, while the Quaternary sedimentary such as Zhangzhou and Fuzhou basins are controlled by NW-trending faults. Mesozoic granite fissure reservoirs are mainly distributed in the southeast coastal areas, such as Zhangzhou, Fuzhou, Fengshun, Yangjiang and southern part of Hainan Province. The distribution of good Mesozoic granite fissure reservoir in these areas is mainly controlled by NE-trending faults. Paleozoic carbonate reservoirs are widely distributed in these areas. Most carbonate rocks are from the upper Paleozoic strata, such as those in the area of Huizhou in Guangdong Province. The major types of geothermal systems in the southeast coastal areas of China belong to medium and low-temperature convection. The geothermal resources developed from the ground to-3 000 m underground could be utilized directly for space heating, greenhouse heating, aquaculture pond heating and industrial uses, as well as other purposes. The geothermal resources with a depth of 3 000~6 000 m underground is mainly featured by Hot Dry Rock(HDR) with a temperature ranges from 150 ℃ to 200 ℃, which is conductive to the development of Enhanced Geothermal System(EGS) and can be utilized for power generation.
基金supported by two projects initialed China Geological Survey: “Evaluation on Soil and Water Quality and Geological Survey in Xiong’an New Area (DD20189122)” and “Monitoring and Evaluation on Carrying Capacity of Resource and Environment in BeijingTianjin-Hebei Coordinated Development Zone and Xiong’an New Area (DD20221727)”
文摘China established Xiong’an New Area in Hebei Province in 2017,which is planned to accommodate about 5 million people,aiming to relieve Beijing City of the functions non-essential to its role as China’s capital and to expedite the coordinated development of the Beijing-Tianjin-Hebei region.From 2017 to 2021,the China Geological Survey(CGS)took the lead in multi-factor urban geological surveys involving space,resources,environments,and disasters according to the general requirements of“global vision,international standards,distinctive Chinese features,and future-oriented goals”in Xiong’an New Area,identifying the engineering geologic conditions and geologic environmental challenges of this area.The achievements also include a 3D engineering geological structure model for the whole area,along with“one city proper and five clusters”,insights into the ecology and the background endowment of natural resources like land,geothermal resources,groundwater,and wetland of the area before engineering construction,a comprehensive monitoring network of resources and environments in the area,and the“Transparent Xiong’an”geological information platform that is open,shared,dynamically updated,and three-dimensionally visualized.China’s geologists and urban geology have played a significant role in the urban planning and construction of Xiong’an New Area,providing whole-process geological solutions for urban planning,construction,operation and management.The future urban construction of Xiong’an New Area will necessitate the theoretical and technical support of earth system science(ESS)from various aspects,and the purpose is to enhance the resilience of the new type of city and to provide support for the green,low-carbon,and sustainable development of this area.
基金supported by the Natural Science Foundation of China(No.42301492)the National Key Research and Development Program(No.2022YFB3904200)+4 种基金the Open Fund of Key Laboratory of Urban Land Resources Monitoring and Simulation,Ministry of Natural Resources(No.KF-2022-07-014)the Natural Science Foundation of Hubei Province of China(No.2022CFB640)the Open Fund of Hubei Key Laboratory of Intelligent Vision Based Monitoring for Hydroelectric Engineering(No.2022SDSJ04)the Opening Fund of Key Laboratory of Geological Survey and Evaluation of Ministry of Education(No.GLAB 2023ZR01)the Fundamental Research Funds for the Central Universities.
文摘If progress is to be made toward improving geohazard management and emergency decision-making,then lessons need to be learned from past geohazard information.A geologic hazard report provides a useful and reliable source of information about the occurrence of an event,along with detailed information about the condition or factors of the geohazard.Analyzing such reports,however,can be a challenging process because these texts are often presented in unstructured long text formats,and contain rich specialized and detailed information.Automatically text classification is commonly used to mine disaster text data in open domains(e.g.,news and microblogs).But it has limitations to performing contextual long-distance dependencies and is insensitive to discourse order.These deficiencies are most obviously exposed in long text fields.Therefore,this paper uses the bidirectional encoder representations from Transformers(BERT),to model long text.Then,utilizing a softmax layer to automatically extract text features and classify geohazards without manual features.The latent Dirichlet allocation(LDA)model is used to examine the interdependencies that exist between causal variables to visualize geohazards.The proposed method is useful in enabling the machine-assisted interpretation of text-based geohazards.Moreover,it can help users visualize causes,processes,and other geohazards and assist decision-makers in emergency responses.
基金This work was supported partly by the National Key Research and Development Program of China(Grant No.2022YFF0503100)the B-type Strategic Priority Program of the Chinese Academy of Sciences(Grant No.XDB41000000)+1 种基金the National Natural Science Foundation of China(Grant Nos.41902317,41941002,41773065)the National Science and Technology Infrastructure Work Projects(Grant No.2015FY210500).
文摘A geologic time scale is a chronological system that separates the geological strata of a planetary body into different units in temporal sequence and shows its progressive evolution.The time scale of the Moon was established a half-century ago during the telescopic-early Apollo exploration era,using data with limited spatial coverage and resolution.The past decades have seen a wide array of studies,which have significantly extended our understanding of global lunar geologic evolution.Based on a comprehensive review of lunar evolution with respect to the dynamical changes,we propose two major updates to the current lunar time scale paradigm to include the evolution of both endogenic and exogenic dynamic forces now known to have influenced early lunar history.Firstly,based on the temporal interplay of exogenic and endogenic processes in altering the Moon,we defined three Eon/Eonothem-level units to represent three dynamical evolutionary phases.Secondly,the pre-Nectarian System is redefined and divided as the magma ocean-era Magma-oceanian System and the following Aitkenian System beginning with the South Pole-Aitken basin.The ejecta of this basin,Das Formation,was deposited on the primordial lunar crust as the oldest stratum produced from exogenic processes.The updated lunar time scale,facilitated by the post-Apollo exploration and research advances,provides an integrated framework to depict the evolution of the Moon and has important implications for the geologic study of other terrestrial planets.
