Geological reservoir and resource potential(10^(13)m^(3))of gas hydrates in the South China Sea

A detailed understanding of the distribution and potential of natural gas hydrate(NGHs)resources is crucial to fostering the industrialization of those resources in the South China Sea,where NGHs are abundant.In this study,this study analyzed the applicability of resource evaluation methods,including the volumetric,genesis,and analogy methods,and estimated NGHs resource potential in the South China Sea by using scientific resource evaluation methods based on the factors controlling the geological accumulation and the reservoir characteristics of NGHs.Furthermore,this study compared the evaluation results of NGHs resource evaluations in representative worldwise sea areas via rational analysis.The results of this study are as follows:(1)The gas hydrate accumulation in the South China Sea is characterized by multiple sources of gas supply,multi-channel migration,and extensive accumulation,which are significantly different from those of oil and gas and other unconventional resources.(2)The evaluation of gas hydrate resources in the South China Sea is a highly targeted,stratified,and multidisciplinary evaluation of geological resources under the framework of a multi-type gas hydrate resource evaluation system and focuses on the comprehensive utilization of multi-source heterogeneous data.(3)Global NGHs resources is n×10^(15)m^(3),while the NGHs resources in the South China Sea are estimated to be 10^(13)m^(3),which is comparable to the abundance of typical marine NGHs deposits in other parts of the world.In the South China Sea,the NGHs resources have a broad prospect and provide a substantial resource base for production tests and industrialization of NGHs.

Defining Cities by Water: Addressing Capital Misallocation in a Race to Conserve Resources

As part of its efforts to promote a sustainable and high-quality development,China has pledged to reduce water consumption and create a water-efficient society.On the basis of identifying the institutional root causes of excessive capital allocation and excessive water consumption in China’s water-intensive industrial sectors,this study elaborates how the national water-efficient cities assessment contributes to optimized capital allocation.Our research shows that national water-efficient cities assessment has motivated local governments to compete for water efficiency.To conserve water,local governments regulated the entry and exit of water-intensive enterprises,discouraged excessive investments in water-intensive sectors,and phased out obsolete water-intensive capacities within their jurisdictions.This approach has resulted in mutually beneficial outcomes,including improved allocation of capital,enhanced water efficiency,and reduced emissions.This paper offers policy recommendations for establishing a water-efficient society throughout the 14^(th) Five-Year Plan(2021-2025)period by presenting empirical evidence on the policy effects of resource efficiency evaluation.

Improving Land Resource Evaluation Using Fuzzy Neural Network Ensembles

Land evaluation factors often contain continuous-, discrete- and nominal-valued attributes. In traditional land evaluation, these different attributes are usually graded into categorical indexes by land resource experts, and the evaluation results rely heavily on experts＇ experiences. In order to overcome the shortcoming, we presented a fuzzy neural network ensemble method that did not require grading the evaluation factors into categorical indexes and could evaluate land resources by using the three kinds of attribute values directly. A fuzzy back propagation neural network （BPNN）, a fuzzy radial basis function neural network （RBFNN）, a fuzzy BPNN ensemble, and a fuzzy RBFNN ensemble were used to evaluate the land resources in Guangdong Province. The evaluation results by using the fuzzy BPNN ensemble and the fuzzy RBFNN ensemble were much better than those by using the single fuzzy BPNN and the single fuzzy RBFNN, and the error rate of the single fuzzy RBFNN or fuzzy RBFNN ensemble was lower than that of the single fuzzy BPNN or fuzzy BPNN ensemble, respectively. By using the fuzzy neural network ensembles, the validity of land resource evaluation was improved and reliance on land evaluators＇ experiences was considerably reduced.

The key parameter of shale oil resource evaluation: Oil content

The United States has become the world's largest oil producer of shale oil. China has abundant shale oil resources, but its resource potential has not yet been exploited. The core of the evaluation is the selection of parameters and their reliability. By combining the parameters of the shale oil resource evaluation, we investigated the key parameters in the evaluation model and reviewed the research results. The adsorption and retention of heavy hydrocarbons, loss of light hydrocarbons, and original oil saturation are key in the evaluation of shale oil resources. The adsorption and retention of heavy hydrocarbons can be determined by the pyrolysis, FID curve, and hydrocarbon generation kinetics of shale before and after extraction. The loss of light hydrocarbons mainly occurs in coring(change in temperature and pressure),sample treatment, which can be evaluated using the GC spectrum, rock pyrolysis, crude oil volume coefficient, mass balance, component hydrocarbon generation kinetics, and other methods. The original oil saturation evaluation includes indirect, direct, logging, and simulation methods. The most reliable parameters can be obtained by using the sealed or pressure-maintained coring immediately after thawing(without crushing), and the recovery of light hydrocarbon loss is critical for the resource evaluation of medium to high mature shale. Therefore, the experimental determination of shale oil content and the study of the influencing factors of the parameters should be strengthened.

Hydrocarbon expulsion model and resource potential evaluation of high-maturity marine source rocks in deep basins:Example from the Ediacaran microbial dolomite in the Sichuan Basin,China

Hydrocarbon expulsion features and resource potential evaluation of source rocks are crucial for the petroleum exploration.High-maturity marine source rocks have not exhibited a hydrocarbon expulsion mode owing to the lack of low-maturity source rocks in deep petroliferous basins.We considered the Ediacaran microbial dolomite in the Sichuan Basin,the largest high-maturity marine gas layer in China,to exhibit a method that quantitatively characterizes the hydrocarbon expulsion of high-maturity marine source rocks.The experiment of fluid inclusion,rock pyrolysis,and vitrinite reflectance(Ro)of 119 microbial dolomite core samples obtained from the Dengying Formation were performed.A hydrocarbon expulsion model of high-maturity source rock was established,and its resource potential was evaluated.The results showed that the Ediacaran microbial dolomite in the Sichuan Basin is a good source rock showing vast resource potential.The hydrocarbon expulsion threshold is determined to be vitrinite reflectance at 0.92%.The hydrocarbon expulsion intensities in the geologic history is high with maximum of 1.6×10^(7)t/km^(2).The Ediacaran microbial dolomite expelled approximately 1.008×10^(12)t of hydrocarbons,and the recoverable resource was 1.5×10^(12)m^(3).The region can be categorized into areasⅠ,Ⅱ,Ⅲ,andⅣ,in decreasing order of hydrocarbon expulsion intensity.Areas with a higher hydrocarbon expulsion intensity have a lower drilling risk and should be prioritized for exploration in the orderⅠ>Ⅱ>Ⅲ>Ⅳ.Two areas,northern and central parts of Ediacaran in the Sichuan Basin,were selected as prospects which had the drilling priority in the future gas exploration.The production data of 55 drilled wells verified the high reliability of this method.This model in this study does not require low-maturity samples and can be used for evaluating high-maturity marine source rocks,which has broad applicability in deep basins worldwide.

Research progress and challenges of natural gas hydrate resource evaluation in the South China Sea

As an efficient clean energy,natural gas hydrate(NGH)has become a hot topic in recent researches.Since1990 s,China has made great achievements and progress in NGH exploration in the South China Sea(SCS),including determination of the favorable distribution areas and favorable strata thickness,identification of the dual source for accumulation,evaluation of the prospective gas contents,verification of the widespread existence,and confirmation of the technical recoverability of NGH resources.However,there are three major challenges in the NGH studies.First,all the 24 national key and major projects in the SCS focused on trial production engineering and geological engineering in the past 20 years,while 8 of the 10 international NGH research projects focused on resource potential.Second,resource evaluation methods are outdated and some parameter selection are subjective.Third,the existing resource evaluation results are low-level with a great uncertainty,and cannot be used to guide NGH exploration and production or strategic research.To improve the evaluation of NGH resources in the SCS,future researches should focus on four aspects:(1)improve the research on the criterion of the objective existence of NGH and the method of prediction and evaluation;(2)apply new theories and methods from the global NGH research;(3)boost the research on the difference and correlation of the conditions of hydrocarbon migration and accumulation in different basins;(4)innovate the theory and method of NGH resource potential evaluation.

THE EVALUATION AND ANALYSIS OF THE TOURISM RESOURCES IN JILIN PROVINCE

This paper comprehensively evaluates and analyzes the tourism resources in Jilin Province, China. And it consists of three parts. The first two parts are on the resources evaluation and analysis. Based on the results of evaluation about the structural and spatial distribution of the tourism resources, it is found that, the natural resources play fundamental roles in Jilin, while the human and cultural resources are important complementary parts as well. In the spatial distribution analysis, the resources show the characteristic of "six clusters"and "three belts"spatial relations. Four clusters are centered on the cities, which are Changchun, Jilin, Baicheng, Tonghua and Ji′an; one cluster is around the Changbai Moutains and one cluster nears the frontier at Tumen between China, Russia and P.D. R. Korea. And the three belts are: 1) The west belt. It contains Xianghai and Momoge natural protection region. The evident of this zone is its ecological and ethical tourism resources. 2)The middle belt characterized by urban traveling and recreation, including Jilin and Changchun, together with their nearby Nong′an and Siping. 3) The last belt is also the most important one, which is the east zone. It covers the Changbai Mountains, the golden triangles of Tonghua and the Tumen River. This zone is remarkable for its abundant natural landscapes and unique folk customs. In the last part the concept planning is briefly constructed for the tourism resources in Jilin Province according to the above evaluation and analysis.

Evaluation of natural gas hydrate resources in the South China Sea by combining volumetric and trend-analysis methods

Natural gas hydrate(NGH),considered as a type of premium energy alternative to conventional hydrocarbons,has been broadly studied.The estimate of the total NGH resources in the world has decreased by more than 90%since the first evaluation in 1973.Geographic and geophysical conditions of the South China Sea(SCS)are favorable for the formation of NGH,which has been proved by drilling results up to date.The recoverability of the NGH in the SCS has been confirmed by the production tests using both vertical and horizontal wells.Since 2001,35 estimates of NGH resources in the SCS have been made,with relatively stable results varying between 600 and 900×109 ton oil equivalent.In these estimations,the volumetric method was commonly adopted,but the geological conditions,the migration-accumulation mechanisms of NGH,and the practical recoverability were not considered.These estimates cannot be regarded as evaluated resources according to the international resource evaluation standards,but are at most about prospective gas content of NGH,thus inefficient for guiding explorations and developments.To solve these problems,this study divides the past NGH surveys in the SCS into seven stages,acquires key geological parameters of every stage based on previous studies and analogy with other areas,evaluates the NGH resources of these seven stages by using the volumetric method,then adopts a new trend-analysis method to simulate the downward trend of these estimates,and finally predicts the NGH resources in the SCS at 2025 and 2030.The downward trend is because of the continuous improvement of NGH understanding over time,which is consistent with the trend of global NGH estimates.At the present stage(from 2019 to 2021),the average technically recoverable resource(ATRR)is 7.0×10^(12)m^(3),and the estimates of 2025 and 2030 ATRR are 6.46×10^(12)m^(3) and 4.01×10^(12)m^(3)respectively,with a difference of less than 40%.Therefore,it can be inferred that the ATRR of NGH in the SCS is between 4.0 and 6.5×10^(12)m^(3),with an average of 5.25×10^(12)m^(3).

Reduction of global natural gas hydrate(NGH)resource estimation and implications for the NGH development in the South China Sea

There have been at least 29 groups of estimates on the global natural gas hydrate(NGH)resource since1973,varying greatly with up to 10,000 times and showing a decreasing trend with time.For the South China Sea(SCS),35 groups of estimations were conducted on NGH resource potential since 2000,while these estimates kept almost the same with time,varying between 60 and 90 billion tons of oil equivalent(toe).What are the key factors controlling the variation trend?What are the implications of these variations for the NGH development in the world and the SCS?By analyzing the investigation characteristics of NGH resources in the world,this study divided the evaluation process into six stages and confirmed four essential factors for controlling the variations of estimates.Results indicated that the reduction trend reflects an improved understanding of the NGH formation mechanism and advancement in the resource evaluation methods,and promoted more objective evaluation results.Furthermore,the analysis process and improved evaluation method was applied to evaluate the NGH resources in the SCS,showing the similar decreasing trend of NGH resources with time.By utilizing the decreasing trend model,the predicted recoverable resources in the world and the SCS are(205-500)×10^(12)m^(3)and(0.8-6.5)×10^(12)m^(3),respectively,accounting for 20%of the total conventional oil and gas resources.Recoverable NGH resource in the SCS is only about 4%-6%of the previous estimates of 60-90 billion toe.If extracted completely,it only can support the sustainable development of China for 7 years at the current annual consumption level of oil and gas.NGH cannot be the main energy resource in future due to its low resource potential and lack of advantages in recovery.

Groundwater system division and compilation of Groundwater Resources Map of Asia

Based on landform, climate, river system, geological structure and hydrogeological structure and from the perspective of systematology, the groundwater system of Asia can be divided into 36 secondary groundwater systems under 11 primary ones by the intercontinental scale. A scientific evaluation of groundwater resources in Asia can be secured using water balance method and runoff modulus method through water circulating analysis and feature study of groundwater system on the basis of groundwater system division of Asia. With natural recharge(runoff) modulus(10~4m^3/km^2·a), the total amount of water resources and those available for exploitation of primary groundwater system can be evaluated-continuous aquifers in plains and basins contain 242.465× 10~9 m^3/a of water, 169.725× 10~9 m^3/a of which is recoverable; discrete aquifers contain 186.695× 10~9 m^3/a, 130.686× 10~9 m^3/a of which is available for exploitation; other scattered aquifers contain 38.614× 10~9 m^3/a, 27.029× 10~9 m^3/a of which could be exploited. In total, there is 467.774× 10~9 m^3/a of groundwater with 327.440× 10~9 m^3/a recoverable. The groundwater map of Asia is compiled according to groundwater system division, evaluation of the total amount and aquifer types to reflect the macro features of groundwater resources in Asia, laying a scientific foundation for exploitation and management of water resources here and for avoiding disputes over groundwater resources and environment among Asian countries.

Evaluation and selection of the ship collaborative design resources based on AHP and genetic and simulated annealing algorithm

The characteristics of the design resources in the ship collaborative design is described and the hierarchical model for the evaluation of the design resources is established. The comprehensive evaluation of the co-designers for the collaborative design resources has been done from different aspects using Analytic Hierarchy Process （AHP） ,and according to the evaluation results,the candidates are determined. Meanwhile,based on the principle of minimum cost,and starting from the relations between the design tasks and the corresponding co-designers,the optimizing selection model of the collaborators is established and one novel genetic combined with simulated annealing algorithm is proposed to realize the optimization. It overcomes the defects of the genetic algorithm which may lead to the premature convergenee and local optimization if used individually. Through the application of this method in the ship collaborative design system,it proves the feasibility and provides a quantitative method for the optimizing selection of the design resources.

Growth behavior and resource potential evaluation of gas hydrate in core fractures in Qilian Mountain permafrost area, Qinghai-Tibet Plateau

The Qilian Mountain permafrost area located in the northern of Qinghai-Tibet Plateau is a favorable place for natural gas hydrate formation and enrichment,due to its well-developed fractures and abundant gas sources.Understanding the formation and distribution of multi-component gas hydrates in fractures is crucial in accurately evaluating the hydrate reservoir resources in this area.The hydrate formation experiments were carried out using the core samples drilled from hydrate-bearing sediments in Qilian Mountain permafrost area and the multi-component gas with similar composition to natural gas hydrates in Qilian Mountain permafrost area.The formation and distribution characteristics of multi-component gas hydrates in core samples were observed in situ by X-ray Computed Tomography(X-CT)under high pressure and low temperature conditions.Results show that hydrates are mainly formed and distributed in the fractures with good connectivity.The ratios of volume of hydrates formed in fractures to the volume of fractures are about 96.8%and 60.67%in two different core samples.This indicates that the fracture surface may act as a favorable reaction site for hydrate formation in core samples.Based on the field geological data and the experimental results,it is preliminarily estimated that the inventory of methane stored in the fractured gas hydrate in Qilian Mountain permafrost area is about 8.67×1013 m3,with a resource abundance of 8.67×108 m3/km2.This study demonstrates the great resource potential of fractured gas hydrate and also provides a new way to further understand the prospect of natural gas hydrate and other oil and gas resources in Qilian Mountain permafrost area.

Analysis of Water Resources Supply and Demand and Security of Water Resources Development in Irrigation Regions of the Middle Reaches of the Heihe River Basin, Northwest China

Based on the data for meteorology, hydrology, soil, planting, vegetation, and socio-economic development of the irrigation region in the middle reaches of the Heihe River basin, Northwest China, the model of balance of water supply and demand in the region was established, and the security of water resource was assessed, from which the results that the effects of unified management of water resources in the Heihe River basin between Gansu Province and Inner Mongolia on regional hydrology are significant with a decrease in water supply diverted from Heihe River and an increase in groundwater extracted. In addition, it was found that the groundwater level has been steadily decreasing due to over pumping and decrease in recharges. In present year （2003）, the volume of potential groundwater in the irrigation districts is far small because of the groundwater overdraft; even in the particular regions, there is no availability of groundwater resources for use. By 2003, water supply is not sufficient to meet the water demand in the different irrigation districts, the sustainable development and utilization of water resources are not secured, and the water supply crisis occurs in Pingchuan irrigation district. Achieving water security for the sustainable development of society, agriculture, economy, industry, and livelihoods while maintaining or improving the abilities of the management and planning of water resources, determining of the reasonable percentage between water supply and groundwater utilization and water saving in agricultural irrigation are taken into account. If this does not occur, it is feared that the present performance of water development and planning may further aggravate the problem of scarcities of water resources and further damage the fragile ecological system.

Evaluation of water resources conserved by forests in the Hani rice terraces system of Honghe County,Yunnan,China：an application of the fuzzy comprehensive evaluation model

The Hani Rice Terraces System, based on gravity-flow irrigation, is one of the Globally Important Agricultural Heritage Systems(GIAHS) pilot sites selected by FAO in 2010. The water resource plays an important role in the sustainable development of this system. The value of water conserved by the forest is influenced by natural, economic and social factors. In this paper, the water quality, per capita water resources, per capita GDP and population density are chosen as indices to construct an index system for a comprehensive evaluation of water resources value. The weights of these indices are 0.443, 0.31, 0.141 and 0.106 respectively, which are determined by the analytic hierarchy process(AHP) method. The water resources value has been assessed by the fuzzy comprehensive evaluation model. The results show that the water resources value in the Hani Rice Terraces System is 4.25 RMB/m^3. Evaluating the value of water resources in the Hani Rice Terraces System can provide a reference for ecological compensation, for raising public awareness of the importance of protecting the system, and ultimately achieving its sustainable development.

Evaluation on water resources carrying capacity of Changchun-Jilin Region

Based on such principles as sustainable development and ecological cycle, this paper evaluates the water resources carrying capacity(WCC) of Changchun-Jilin region using a population-economy-water resources correlation evaluation model built on the basis of WCC evaluation method as elaborated in the methodology of Functional Zoning of Population Development. Results show that the annual WCC of Changchun-Jilin region is able to support the population there, as a basic balance is struck between population and water resources. The incorporation of WCC into overall urban planning is one of the building blocks for sustainable city development with an advisable size.

Evaluation and analysis on the tourism resources in Hami Region based on GIS mapping technology

According to the data from the national standard classification and investigation of tourism resources(GB/T 18972-2003) in Hami region,the abundance,quality and dimensional distribution of the tourism resources in Hami region were evaluated based on GIS mapping technology.The evaluation results on the tourism resources in Hami region are described as follows:there are rich tourism resources categories;the quality of tourism resources is ordinary;the resources distribute equably;the number of the historical resources is much more than the natural resources,but the 1atter still has great potential for developing.All the results of the evaluation can provide important references for strategic decision making of Hami region.

Application of Bayesian Network Learning Methods to Land Resource Evaluation

Bayesian network has a powerful ability/or reasoning and semantic representation, which combined with qualitative analysis and quantitative analysis, with prior knowledge and observed data, and provides an effective way to deal with prediction, classification and clustering. Firstly, this paper presented an overview of Bayesian network and its characteristics, and discussed how to learn a Bayesian net- work structure from given data, and then constructed a Bayesian network model for land resource evaluation with expert knowledge and the dataset. The experimental results based on the test dataset are that evaluation accuracy is 87.5%, and Kappa index is 0. 826. All these prove the method is feasible and efficient, and indicate that Bayesian network is a promising approach for land resource evaluation.

Strategic Application of Evaluation Resources——Positive Discourse Analysis toward“UN Secretary-General’s Message for New Year”

This study applies Halliday’s systemic functional grammar,especially the evaluation theory of Martin and Rose,to conduct positive discourse analysis toward“UN Secretary-General’s Message for New Year”from the aspect of context,transitivity,evaluation system and so on.And it discusses how the author of the discourse takes advantage of language resources,especially evaluation system resources,to convey the information clearly in the implied.

Research on Evaluation and Development of Industrial Heritage Tourism Resources in Textile Valley

This paper selects Qingdao Textile Valley as the research object,establishes the evaluation system of industrial heritage tourism resources,and analyzes the evaluation factors of industrial heritage tourism resources,such as resource element value,market location value,and environmental factors.Then this paper puts forward some effective suggestions to promote the development of industrial heritage tourism in Textile Valley.The results show that the measures put forward,such as fully tapping the value of resource elements,improving the surrounding traffic environment,perfecting tourism signs,perfecting local traffic routes,improving the complementarity of tourism resources,and expanding the tourist market,can scientifically and effectively protect urban industrial heritage,improve the development level of urban tourism,and speed up the transformation of new and old energy in Qingdao.

Deep bedrock geothermal resources in the Maichen Sag,Beibuwan Basin and their potential for exploitation and utilization

The Maichen Sag in the south-central part of the Beibuwan Basin is abundant in geothermal resources that have not been widely exploited and utilized due to inadequate research on it.This study evaluated the geothermal resources in the Maichen Sag based on the regional geological setting and geothermal conditions.Grid units for assessment and a geological model for areas with geothermal resources were established using spatial analysis techniques.The spatial distribution models of the physical and thermophysical properties of the geothermal reservoirs were also built using the Kriging interpolation method.Based on the terrestrial heat flow distribution in the target areas,the spatial distribution of the geo-temperature field through the inversion under the constraints of the temperature data from boreholes were predicted.Factors such as deep geo-temperature,thermophysical properties of rocks,and terrestrial heat flow values,were integrated into this quantitative evaluation of geothermal resources through the geological modeling-based volume method and the geothermal reservoir engineering-based numerical simulation method.The results show that the Maichen Sag has favorable heat source conditions with intersected,deep-rooted faults and widely developed Upper Paleozoic fissured granite geothermal reservoirs.The northern outer slope zone at a burial depth of 3‒5 km on the tectonic plane of the basement in the sag is suggested to be a potential target area,where,as calculated using the volume method,is likely to be the home to the total geothermal resources of 80.4×10^(9)GJ(i.e.,2.75×10^(9)tonnes of coal equivalent(tce))in the bedrock geothermal reservoirs at a burial depth of 3‒6 km.The geotemperature of 172‒201℃at a formation depth of 5 km in the sag also indicates that the deep geothermal resources are of high value for exploitation.