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The investment problem of oilfield development is to trade off the investment exploration investment and development investment. With low return on investment got by using the existing method to solve this problem, we construct an optimal model to improve it based on Data Envelopment Analysis (DEA) method and the relations about investment and proven reserves, investment and output as well as production cost. Data Envelopment Analysis (DEA) method is used to present a method to determine the optimal scale of productivity construction investment in unit production. The relation between total cumulated proven reserves and cumulative exploration investment is denoted as an exponential model. The relation among productions and remaining recoverable reserves as well as production cost may be described as an exponential operational cost function. Based on above two relation models and investment effectiveness coefficients of every block, we establish an optimal model whose objective function is net present value (NPV) profit maximum, whose constrain conditions include investment, reserve/production ratio, production and some equality constraints under the mode of sustainable development. It can be solved by genetic algorithms. The result of case study shows that this optimal investment of oilfield development has multi-stage investment structure under given conditions; the model can provide scientific basic theory for oil companies to make a long-term strategic program and investment plan in oil exploration and development, may decrease the subjective blindness in the investment and bring about a reasonable and orderly exploration and development of oil resources.

With the increasing demand for energy around the globe, hydrocarbon explorations move towards the Arctic region that holds a majority of unexploited oil reserves. The harsh environmental conditions with sub-zero ambient temperatures and high winds demand winterization techniques for pipes, instruments and equipment to carry out uninterrupted plant operations. The natural phenomenon: hydrate formation, is considered to be a major flow assurance problem starting from the wellhead through the final point in the delivery system which could be addressed through winterization. Developing winterization strategies for arctic conditions is a challenging task demanding rigorous and robust approaches. Risk-based winterization is a novel approach, adapted for vessels operating in arctic environments. In this paper a new model is proposed to calculate the probability of hydrate formation and its associated risk for a given loading scenario. The winterization requirement is determined based on the estimated risk. Two case studies presented here demonstrate the applicability of the proposed model and compare several winterization methods to find an optimal solution.

Formation water can in principal be used to identify hydrocarbon reserves. One such potential reserves are the gas reservoirs in the Ordos basin in China. However, there is limited data for this basin; we thus investigated the geochemical properties of a large range of formation water acquired from the Ordovician in the Ordos basin (42 brine samples obtained from different wells at M5 member) and analyzed their chemical characteristics. The results showed that this formation water is associated with a sealed reservoir, which is good for hydrocarbon storage. This is also related to the demonstrated strong diagenetic transformations. We also proposed statistical relationships between these geochemical properties and hydrocarbon storage based on a machine learning method (Decision tree). The results suggest that the salinity, Na+/Cl− ratio, (Cl−-Na+)/Mg2+ ratio, (HCO3−-CO32-)/Ca2+ ratio and Mg2+/Ca2+ ratio highly correlate with the gas preservation. The results thus provide drastically more accurate predictions in terms of where to find gas reservoirs in the Ordos basin, and can thus lead to significantly better exploitation of these resources.

Gas condensate reservoirs constitute a significant portion of global hydrocarbon reserves. In these reservoirs, liquids develop in the pore space once bottomhole pressure falls below dew point. This results in the formation of a liquid bank near the wellbore region which decreases gas mobility, which then reduces gas inflow. In such complex reservoirs, it is important to correctly describe PVT impacts, adjustments to well test analysis and inflow performance, and then combine all effects in the reservoir analysis. The literature contains many references to individual adjustments of PVT analysis, well testing, or inflow performance for gas condensate reservoirs, but few studies demonstrate the complete workflow for reservoir evaluation and production forecasting in gas condensate fields. This research uses a field case study to demonstrate an integrated workflow for forecasting well deliverability in a gas condensate field in North Africa.The workflow incorporates a description of the retrograde behavior that impact the well deliverability. The workflow begins with the interpretation of open-hole log data to identify the production interval net pay and to estimate petrophysical properties. A compositional model is developed and matched to actual reservoir fluids. Several gas condensate correlations are used to obtain the gas deviation factor and gas viscosity in order to count the change in gas properties with respect to pressure. Transient pressure analysis is described and used to identify reservoir properties. Inflow performance relationships (IPRs) are analyzed using three types of back pressure equations. The workflow integrates all data in a numerical simulation model, which includes the effect of bottom water drive.Results show that in this field case study, reservoir behavior is composite radial flow with three regions of infinite acting radial flow (IARF). Using compositional simulation, it is found that the fluid sample for this field is a lean gas condensate since the liquid drop-out represented 1% of the maximum liquid drop-out. In addition, liquid drop-out increases by 0.1% for every 340 psi drop in reservoir pressure, which reduces the AOF by 3.4%.The results provided in this case study demonstrate the importance of an integrated workflow in predicting future well performance in gas condensate fields. The study demonstrates how to implement the workflow in managing or developing these types of reservoirs.

Marine shale gas in South China is widely distributed and demonstrates an enriched resource. Compared with the North American commercial shale gas field, the shale formation in South China is featured by old age, multiple stages tectonic movements, and high thermal evolution degree and complex reservoir forming conditions. As a result, the existing theories and technical methods of exploration in North America cannot be simply applied to South China. Since 2007, based on the in-depth study on a large quantity of analytical test data, we have conducted the theory and technology research for the southern marine shale gas, found Wufeng-Longmaxi Group deep water shelf high-quality shale gas critical parameters coupling laws, proposed the “Binary Enrichment” theory for highly evolved marine shale gas in southern complex tectonic zone, and established a zone selection and evaluation criteria, which are based on the quality of shale, for the key of preservation condition, and for the purpose of economy. Taking this as a guide, we selected Longmaxi formation Lower Silurian of Fuling area in southeastern Sichuan Province as the preferred breakthrough field for the shale gas exploration. The Jiaoye 1 well has the daily gas production of 20.3 × 104 m3, which embarked the found of China’s first large-scale business development gas field, the Fuling shale gas field. And we submit the first domestic shale gas proven reserves of 1067.5 × 108 m3. The Fuling shale gas reservoirs are deep water shelf marine high-quality shale, with favorable thickness and even distribution, without dissection in the middle. They are typical self-generation and self-storage shale gas reservoirs. The gas fields have high production gas well; high pressure gas reservoir, good gas components and good exploit results, and there for the Fuling shale gas field is characterized by mid-depth, high pressure, high reservoir pressure, and high quality gas accumulation. Up to March 24, 2014, all of the 101 fracture-gas testing wells have obtained middle and upper shale airflow, with the average single well test production of 32.6 × 104 m3/d. In the exploration and development process, technology series in geological evaluation, horizontal well, drilling, well completion, piecewise fracturing techniques have been gradually formed. It is of great importance to commercially develop the domestic shale gas and promote the restructuring of China’s energy structure.

As the largest producer of gold in the world, China's gold reserves are spread across a number of orogenic belts that were constructed around ancient craton margins during various subduction–collision cycles, as well as within the cratonic interior along reactivated paleo-sutures. Among the major gold deposits in China is the unique class of world's richest gold mines in the Jiaodong Peninsula in the eastern part of the North China Craton with an overall endowment of > 3000 tons. Following the dawn of metal in the third millennium BC in western China, placer gold mining was soon in practice, particularly during the Xia, Shang and Zhou dynasties. During 1096 AD, mining techniques were developed to dig underground tunnels and the earliest mineral processing technology was in place to pan gold from crushed rock ores. However, ancient China did not witness any major breakthrough in gold exploitation and production, and the growth in the gold ownership was partly due to the ‘Silk Road’ that enabled the sale of silk products and exquisite artifacts to the west in exchange of gold products. In the modern times, the proven reserves of gold resources in China have steadily increased from 4614.7 tons in 2005 up to 6864.79 tons in 2010, with a growth rate of 48.76%. In the past ten years, the rate of production increased by 70%, launching China as the top producer of gold in the world in 2008 when the production reached 300 tons per year. The gross industrial output of gold industry in China increased sharply from 20.82 billion Yuan up to 229.29 billion Yuan between 2000 and 2010, registering 9 times growth, and breaking the world record. A simultaneous hike in the proportion of gross value in GDP from 0.21% in 2003 up to 0.58% in 2010 is also recorded.

The Chinese government has introduced numerous policies and development plans to boost its shale gas industry in recent years. However, China’s shale gas exploration and development is still in the initial stage and has been confronted with many challenges. This paper systematically analyzes the current status of China’s shale gas industry from five aspects for the first time—resource situation, exploration and development status, policy and planning situation, technology status and international cooperation—then respectively elaborates on the different obstacles of shale gas development in the short run and the medium and long term. We argue that short-term barriers to the Chinese shale gas industry mainly include objective factors, such as geological and surface conditions, shale gas proven reserves, technology innovation and environmental concerns, while some man-made obstacles (except for water scarcity) may restrict shale gas development in the medium and long term. In order to better tackle the short-term challenges, this paper proposes policy recommendations from five perspectives: strengthening the investigation and evaluation of China’s shale gas resources; perfecting shale gas industry policy; establishing a national shale gas comprehensive experimental zone; enhancing scientific and technological research; and establishing a shale gas regulatory system with an emphasis on environmental protection and supervision.

Main source of energy fuel in Bangladesh is natural gas and day by day it is trimming the proven reserves. There are provisions of potential renewable energy resources like the solar, wind, tidal etc.; but the initiatives are very slow. Coal reserves and their prospects could not assure the nation as there are proven coal reserves of about 4,750 Mt (equivalent to 975 GM 3 of gas, which is around 3 times greater than the present gas reserve in Bangladesh). Those coal reserves are discovered in the North-Western part of Bangladesh at the depth ranging 200-1100 m. The special feature of the coal seams are found in the same geological formation and thickness is high (on average 38-64 m).One of the major issues, is the minable amount of the resources in conventional mining method. Barapukuria coal mine is under operation since 2005 and running a 250 MW coal fired power plant. But the mining method is not yet proven as suitable one, due to jointed layer thick coal seam (51 m) with faulty overburden and wider aquifer zone. The underground mining environment is hazardous including high temperature, suffocative humidity and releasing of unpredictable carboneus gases from the coal faces which make the life expectancy of this mine questionable. The geographical position and climatic conditions of Bangladesh, especially the monsoon rain extends several weeks to months which are major setback for economic viability of the open striping mining. The policy makers still could not finalize the national coal policy. In this stage the government is stepping up for construction of coal fired power stations run by imported coal. A group of skilled and dedicated entrepreneur is seeking the pathways for exploiting unminable coals within a safe engineering framework and bringing the global Underground Coal Gasification (UCG) projects under the same umbrella. India, Pakistan, Indonesia, Japan even the Vietnam has already joined the cohort. But why not Bangladesh, though they have huge amount of coal reserves which are not minable in conventional methods. This paper presents a review on development of this technology, investigates the geology and formation of the deposits and seeks suitability of the gasification methods as a sustainable engineering model considering social, environmental & economic issues, which may be helpful for fore stepping towards unconventional coal extraction activity for combating energy crisis.

This paper investigates the conditions leading to the indefinite termination of production in four critical primary panels at an underground coal mining operation, the observed shortcomings in the mining approach, and the proposed strategy to mine through the affected panels. Initial assessment of the abandoned panel conditions indicated time-dependent strata failure, (i.e. bolted roof failure overrunning intersections), which occurred from mere minutes to up to four weeks post-production, with and without prior warning of failure. This prompted the constant re-supporting of back areas, which raised safety and productivity concerns. Investigation of the initial mining conditions revealed that the failures were due to a critical combination of factors, the chief of which was isolated horizontal stress. Other factors that were initially overlooked by the mine (i.e. influence of hydraulic stress, misinterpretation of borehole data), resulted in the conditions being described as abnormal. Remedial actions were determined, and in so doing, a new strategic approach was formulated to thoroughly address all failure concerns. The four panels were explicitly planned to serve as the main intake and return airways for the recently commissioned secondary ventilation shaft, as well as providing access to millions of tons in proven coal reserves. It is thus imperative to mine the panels. A feasibility study showed that the proposed strategy set for implementation would be financially viable.

Summary Located in the sea area of the Bohai Bay Basin, offshore China, Chengbei Sag is a NW-trending Cenozoic half graben, with faulting in the northeast direction and overlapping in the southwest direction. The differential evolution of the NW-trending sag-controlling fault in the northeastern part results in two sub-sags in the northern and southern parts, with respective proven reserves of 10 million tons and 300 million tons. Comprehensive analysis combining the seismic and well data reveals that the two sub-sags share similar fault system characteristics, major fault properties, formation development, and unconformity distribution. Meanwhile, there are also differences in formation thickness and source rock burial depth though source rocks in both sub-sags have reached the hydrocarbon generation threshold and thus can provide sufficient oil and gas. The northern sub-sag is of great exploration prospect, and the exploration and development of it can refer to that of the southern sub-sag. To be specific, we should highlight the areas under the unconformity in the gentle slope belt, in the shallow faulting zone in the steep slope belt, and inside the uplifted buried hill.

This paper explores some basic economics of the climate change issue and how government response may impact the petroleum industry. Possible economic aspects are addressed by examining past and projected fossil fuel production numbers, calculating their resulting emissions, and then projecting how regulations or taxes might affect energy prices and production. Nine medium to major petroleum companies, which do business in the USA, are currently factoring in some kind of carbon emission restrictions into their long-range business plans. A driver for these plans is that the vast majority of countries, including the world’s largest emitters, have formally agreed to limit their emissions to avoid a 2°C (3.6°F) rise in global temperatures. Because there is no agreement yet on a set number of allowable emissions, this paper utilizes estimated carbon budgets from one paper, Meinshausen et al. (2009). Some pertinent results derived herein are the following: 1) oil and natural gas only comprise 33.3% of potential emissions from fossil fuels; 2) under a probability scenario of exceeding 2°C (3.6°F), all proven reserves of oil and natural gas (as of 2012) could be consumed, whereas only 56% could be utilized with continued coal consumption. To demonstrate how a market approach might limit carbon emissions, a simple model shows how an annually increasing carbon tax affects the relative price of fossil fuels and alternative energy. The objective of this paper is to present arguments that there are economic reasons for American Association of Petroleum Geologists (AAPG) to address the issue of climate change.

We propose reforming the Brazilian regulatory safety framework (BRSF) for offshore oil and gas production and drilling operations. Brazil has emerged as a leading offshore producer with extensive proven reserves yet to be exploited. However, the BRSF has not been updated since 2007, and there are now major concerns about the industry׳s safety, particularly after the BP Deepwater Horizon accident, along with the technical challenges due to extreme conditions under which Brazil׳s resources are located. Drawing on experiences from three leading offshore oil and gas producers (Norway, the UK, and the US), we recommend the adoption of three best practices: the UK׳s ‘safety case’ approach (where operators are expected to provide convincing and valid arguments that a system is sufficiently safe for a given application in a specific environment), Norway׳s ‘barrier management’ (evidence that there are at least two tested and independent barriers to avoid accidents) and greater investment in safety research and development, as suggested by the US׳s National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling. We discuss implications for policy reform and how best practices can be applied within the Brazilian context.

Peru׳s Camisea gas fields hold nearly 90% of the country׳s natural gas reserves. In the 1990s, the government had a policy to prioritize Camisea gas for domestic consumption. The revocation of this policy in the 2000s allowed private developers to export 40% of Camisea׳s proven reserves, equivalent to one third of Peru׳s total. This USD 3.9 billion liquefied natural gas (LNG) export project boasts the largest single foreign direct investment in Peru׳s history. A major component of the financing was granted by international financial institutions on economic grounds. While the project was expected to yield a substantial return to private investors, the export of one third of Peru׳s total proven natural gas reserves is not in line with its long-term interests. We undertake cost–benefit analyses for a series of scenarios, starting with the project׳s formative stage in the mid-2000s, and then in 2012, two years after it began its commercial operation. In all cases, Peru does not have sufficient reserves to warrant export, and the economic costs far exceed the benefits. This policy of LNG exports should not have been approved by the government, nor should the loans have been granted by international financial institutions to make it possible.

In recent years, the proven reserves of lithological reservoirs account for a little more than two-thirds of the total proven reserves in SL Oilfield. The seismic predication technique as the key exploration method of lithological reservoirs focuses on identifying and describing reservoirs, especially on sand bodies. For the lacustrine faulted basin with various complex lithological reservoirs, based on the different geological characteristics of the reservoirs, a series of techniques suitable for channel sand, sandy conglomerate, turbidite and beach bar reservoirs have been developed and applied in the lithological reservoir identification and description and have made great progress in the actual exploration.PrefaceSince 1990s, the exploration in SL Oilfield has already developed to that of subtle reservoirs. The proven reserves of lithological reservoirs account for nearly 70% of the total reserves. The seismic predication technique as the key exploration method of lithological reservoirs focuses on identifying and describing reservoirs, especially on sand bodies. For lithological reservoir exploration in complex geologic conditions, lots of studies have been completed in order to obtain great success in many areas [1-7]. With the increasing degree of exploration, lithological reservoirs will become the key role in the future. It is very important to apply geophysical data for identification and description of lithological reservoirs. It has significant effect to improve exploration benefit and the production.

In 2007, Ghana joined the club of Gulf of Guinea oil-rich countries when transnational corporations discovered proven reserves in the Jubilee Field, off of the Cape Three Points along its Western coast. This has generated debate on whether Ghana would escape the resource curse. The orthodox resource curse approach (ORCA), dominant in most discussions on the issue to date, offers some valuable theoretical and policy insights but is also highly problematic: it is uncritical, ahistorical and reductionist. Fixated on internal political and economic factors, the ORCA ignores the longue duree of capitalist exploitation and its negative structural effects on the economy. This article formulates a critical political economy approach (PEA) which brings a fresh perspective on the oil-curse debate, focusing specifically on the case of Ghana. Using theoretical argumentation and empirical evidence, the paper explains why, in the context of ORCA, many would argue that a liberal democratic context, relatively good governance and long history of gold mining will help Ghana minimise the probability of a resource curse. But when analysed using a more dynamic PEA, it becomes clear that the danger of a resource curse ‘epidemic’ surfacing in Ghana is very real: the continuous exploitation by global capital, which has perpetuated the existence of enclave extractive industries and a dependence on the export of low-value commodities. A PEA brings into sharper focus the global political economy underpinnings of the resource curse in Sub-Saharan Africa by highlighting the way in which the dynamics of ‘uneven and combined’ capitalist development have conditioned the region, both resource-rich and poor, to become dependent on the production and export of raw commodities.

We present two examples of describing low permeability Neogene clastic lithofacies to outline unconventional hydrocarbon lithofacies. Both examples were selected from the Drava Depression, the largest macrostructure of the Pannonian Basin System located in Croatia. The first example is the Beničanci Field, the largest Croatian hydrocarbon reservoir discovered in Badenian coarse-grained clastics that consists mostly of breccia. The definition of low permeability lithofacies is related to the margins of the existing reservoir, where the reservoir lithology changed into a transitional one, which is mainly depicted by the marlitic sandstones. However, calculation of the POS (probability of success of new hydrocarbons) shows critical geological categories where probabilities are lower than those in the viable reservoir with proven reserves. Potential new hydrocarbon volumes are located in the structural margins, along the oil-water contact, with a POS of 9.375%. These potential reserves in those areas can be classified as probable. A second example was the Cremušina Structure, where a hydrocarbon reservoir was not proven, but where the entire structure has been transferred onto regional migration pathways. The Lower Pontian lithology is described from well logs as fine-grained sandstones with large sections of silty or marly clastics. As a result, the average porosity is low for conventional reservoir classification (10.57%). However, it is still an interesting case for consideration as a potentially unconventional reservoir, such as the ”tight” sandstones.

What's Wrong with Climate Politics, and How to Fix It. By Paul G. Harris. Cambridge: Polity Press, 2013. 296 pp., $21.80 paperback (ISBN-13: 978-0-745-65251-1). Institutionalizing Unsustainability: The Paradox of Global Climate Governance. By Hayley Stevenson. Los Angeles: University of California Press, 2012. 308 pp., $29.67 paperback (ISBN-13: 978-1-938-16902-1). Influenced by an obsession with economics and technology, most energy and climate analysts frequently ask the wrong questions. They will ponder how large proven reserves of oil and gas are being extracted rather than challenging the need to utilize oil and gas in the first place, or asking whether oil and gas infrastructures are fair to their workers or the communities that live near them. They will assess and model energy prices and technological learning curves, rather than ask how existing energy infrastructures benefit some people to the exclusion of others. They will map energy and climate scenarios, track atmospheric concentrations of carbon dioxide, and discuss the pros or pitfalls of the United Nations Framework Convention on Climate Change, but refrain from interrogating the underlying logic behind an international economic system that continues to emit dangerous amounts of greenhouse gases. The standard dogma of climate change discourse—that it is a technical problem best left to experts and scientists to resolve—is so entrenched that it is incredibly refreshing when knowledgeable people offer an alternative view. It is even more rewarding when their analysis is penetrating, well written, and well argued, as is the case with both Paul G. Harris's (2013) What's Wrong with Climate Politics and Hayley Stevenson's (2012) Institutionalizing Unsustainability . Harris begins by arguing that there are three fundamental reasons we have failed to develop adequate political responses to climate change. The “cancer of Westphalia” refers to an international system which encourages countries to fight for narrow, short-term interests. The “malignancy of great polluters” refers to the inability of the United States and China to do anything about it. The “addictions of modernity” refer to growing levels of pollution that accompany our modern lifestyles. This tripartite framing of challenges then leads us to Harris's three solutions. We should seek …

The Brazilian energy sector has undergone significant changes in recent decades. In particular, consumption and production of natural gas have intensified, and more infrastructures for its transport and importation have been built. In addition, recent discoveries (such as the huge natural gas volumes located in offshore fields) and new research into unconventional deposits indicate a rise in Brazil's proven natural gas reserves in the near future. However, Brazil lacks the geological or underground storage facilities to support its rapidly expanding gas industry, as well as important tools for meeting fluctuating demand and production and improving supply security. To assess the required storage capacity for Brazil, it is useful to analyze the international experience, clarifying the development of several aspects of the gas industry in gas storing nations. To this end, we investigated the relationships between storage and various characteristics of the gas sector by linear regression analysis. The research, conducted on all 38 countries with operational underground natural gas storage, evaluated the extent to which storage capacity is affected by proven reserves, production, consumption, infrastructure, total gas imports and exports, and the use of natural gas as a percentage of total national energy consumption. A very strong relationship emerged between underground natural gas working storage capacity and gas consumption (R2 = 0.8825) and gas infrastructure (R2 = 0.9130). Another important relationship was identified between storage and gas production volume (R2 = 0.8239). The remaining aspects did not significantly affect the development of gas storage activity. We estimated the deviations between the values calculated by the linear regression equations and those reported in the technical literature. The errors varied from 89.1%, when all 38 countries were involved, to 31.4%, considering the 13 nations with the highest working gas storage capacities. The average deviation was significantly higher for the 12 nations with little storage capacity (as high as 288%); excluding these 12 countries, the average error reduced to 37.4%. Thus, the equations obtained by the correlations more accurately predicted the outcome in countries with higher storage capacity. The large deviations for countries such as Argentina, China, and Sweden are discussed. Finally, the required storage for the Brazilian gas sector was determined at two intervals: (i) 0.34–9.22 billion m3, based on the error of 89.1%, and (ii) 1.98–6.70 billion m3, based on the deviation of 37.4%. It is important to mention that high errors were expected, since gas storage depends on factors such as geology and demand seasonality, which were not considered in this work, but which could be analyzed in future researches.

Oil is a much sought after resource in the modern world economy. Until the previous decade, Middle East was thought to hold the maximum proven reserves of oil. This provided an incentive for western nations to maintain peace and stability in the region. However, discovery of new oil reserves in Brazil, Venezuela, Canada, Alaska and Russia, have challenged the status quo. Emerging Asian economies, namely India and China, will have to deal with an unstable supplier for one of the most important components in their energy portfolio.Given the situation, India is especially at risk as it imports almost 70% of its oil requirement, up to 65% of which originates from the Middle East. In a disruptive scenario of disturbance in the Middle East, India would find it difficult to meet its oil needs, jeopardizing its energy future. This paper analyzes India's energy consumption pattern, consumption of oil and oil products over the past four decades and the composition of India's oil import sources over the past five years. Finally, a model is proposed to secure India's energy future.

Based on a comprehensive analysis, the geological and geochemical characteristics of large gas fields in China were summarized in this paper. By the end of 2011, altogether 48 large gas fields had been discovered in China, with their proven reserves accounting for 81.5% of the total proven gas reserves in China. The main geological and geochemical characteristics of large gas fields in China are as follows: (1) Alkane gases are the main components of natural gas, with an average methane content of 88.22%, and the average contents of ethane, propane and butane of 3.31%, 0.97% and 0.49%, respectively; (2) The natural gases in 27 of the 48 large gas fields are coal-derived gases which indicate coal-derived gas is the major genetic type of natural gas in China; (3) Reservoirs are in multiple strata, but natural gas is mostly produced from the Permian and Triassic; Sandstones, carbonates and volcanics are the main reservoirs, of which the sandstones have the most reserves; (4) There are 16 tight gas fields in the 48 large gas fields, suggesting the crucial importance of this type of reservoirs in China; (5) Most of these large gas fields were formed at late or very late stages, suggesting late reservoir formation is favorable for gas preservation; (6) Multiple reservoir types are identified, including structural, lithologic and stratigraphic reservoirs. Key words: China, large gas field, geological characteristics, geochemical characteristics, coal-derived gas, oil-type gas

By the end of 2011, 20 giant gas fields with proven reserves over 1000×108m3 had been discovered in 7 sedimentary basins in China. Based on the molecular and the carbon isotopic compositions of the alkane gases in these gas fields, in combination with the δ13C1-δ13C2-δ13C3 and δ13C1-C1/C2+3 identification diagrams, the origin of the alkane gases in these 20 giant gas fields are discussed: the alkane gases in Sulige, Daniudi, Yulin, Zizhou, Wushenqi, Hechuan, Guang'an, Anyue, Yuanba, Xinchang, Kela2, Dina2, Dongfang1–1and Kelameili giant gas fields are mainly coal-derived; the alkane gases in Tazhong1 and Datianchi giant gas fields are oil-derived; the alkane gases in Tainan giant gas field are bacterial gases; the alkane gases in Jingbian giant gas field are mixed gases mainly composed of coal-derived gases supplemented with a small quantity of oil-derived gases; the alkane gases in Puguang giant gas field are mixed gases mainly composed of oil-derived gases supplemented with a small quantity of coal-derived gases; the alkane gases in Xushen giant gas field are mixed gases mainly composed of abiogenic gases supplemented with a small quantity of coal-derived gases. The study on the genetic types of the alkane gases in these fields is not only of great scientific importance to the gas correlation, gas accumulation research and the optimization of the exploration targets, but also to the acceleration of the Chinese natural gas industry.

This study aims to give information about the oil production of 42 Oil Fields and the wells of each field in Diyarbakir and the surrounding area where is geologically located at the boundary of Anatolian plate and Middle Eastern oil region in the Southeastern Anatolia of Turkey. The structure of oil reservoirs at this region, the interaction of oil and water at the reservoir, capping mechanism of reservoir oil and water are the given topics about the reservoir. Average drilling depth of oil wells at the surrounding area, chemical structure and physical properties of production formations, calculation of production rate, pump types and selecting the suitable type of pump for several production rates, advantages and disadvantages of the pump types are also the other given information about the region. Moreover, regional evaluation of the oil and water ratios, API gravity of produced oil, salinity and pH values of produced water are mentioned by using the analysis of samples taken from the wells in different regions of Diyarbakir province. The other purpose of the study is to inform about stocking of produced oil and water by using surface systems, seperation systems of oil from the water, injecting of seperated water to water injection wells, analysing the downhole and surface equipment failures for production wells and enviromental effects of oil production. Giving information about the economical aspect of the oil production for Turkey and Diyarbakir region is also one of the other goal. Solutions are offered for the encountered problems during the production, separation, transportation, and the refinery processes of the reserves in Diyarbakir city of Turkey, that imports most of its petroleum and natural gas use despite being very close to relatively large reserves.

Interest has rapidly grown in the use of unconventional resources to compensate for depletion of conventional hydrocarbon resources (“easy hydrocarbon”) that are produced at relatively low cost from oil and gas fields with large proven reserves. When one wants to ensure the prospects for development of unconventional resources that are potentially vast in terms of their energy potential, it is essential to determine the quality of that energy. Here we consider the development of shale gas, an unconventional energy resource of particularly strong interest of late, through analysis of its energy return on investment (EROI), a key indicator for qualitative assessment of energy resources. We used a Monte Carlo approach for the carbon footprint of U.S. operations in shale gas development to estimate expected ranges of EROI values by incorporating parameter variability. We obtained an EROI of between 13 and 23, with a mean of approximately 17 at the start of the pipeline. When we incorporated all the costs required to bring shale gas to the consumer, the mean value of EROI drops from about 17 at the start of the pipeline to 12 when delivered to the consumer. The shale gas EROI values estimated in the present study are in the initial stage of shale gas exploitation where the quality of that resource may be considerably higher than the mean and thus the careful and continuous investigation of change in EROI is needed, especially as production moves off the initial “sweet spots”.

Recent studies have evaluated the climate change implications of burning all of the world's proven reserves of carbon. To stay below the ambitious target of two degrees Celsius of warming above average pre-industrial temperatures, the International Energy Agency (IEA) estimates that we would need to emit no more than 884 GtCO 2 globally between 2012 and 2050, equivalent to burning approximately one third of current global carbon reserves. This would require leaving large amounts of coal, oil and natural gas in the ground. These unutilized fossil reserves have been referred to as “stranded”. In this paper, we analyze CCS not as a cost, but as a potential enabler of utilizing otherwise stranded fossil fuels. We examine case studies at Boundary Dam and Gorgon, introduce a “CO 2 Normalized Price” as a useful metric for bottom-up assessments, and evaluate top-down model results to help value CCS as a way to rescue stranded fossil fuel assets.

Coalbed gas, also called coalbed methane gas, is a kind of unconventional natural gas located in coal and rocks, coexisting with coal and its main ingredient are methane. On different levels of structure, coal bed methanes adsorption has partition zonality. The gas-bearing of coal seams has relative concentration in different tectonic units, is known as coalbed methane (CBM) enrichment. Influenced by coal rank, coal, rock properties and various geological conditions and other factors, the enrichment has certain regularity. In the study of the coal bed gas enrichment, coal bed gas enrichment especially refers to coal bed methane enrichment. Economic evaluation is that it may analysis reserves financial feasibility and economical rationality for coal seam to get the best economic benefit evaluation, by various stages in CBM cost and final production and income situation.

Catastrophic climate change (C3) is inevitable if carbon emissions to the atmosphere are not rapidly reduced and the now unsafe atmospheric level (400 ppm) CO2 (and rising) is not brought down by sequestration technologies to below 350 ppm. C3 prevention is possible with the replacement of global fossil fuel supplies by wind, concentrated solar power and photovoltaics, with the main obstacle being the political economy of global capitalism, specifically the Military Industrial (Fossil Fuel, Nuclear, State Terror) Complex. C3 prevention likely requires global demilitarization, agroecologies replacing industrial/genetically modified organism (GMO) agriculture, solarization, and democratic, bottom-up governance. Energy poverty in the global South must end, reaching a rough minimum of 3.5 kilowatt/person. This solar transition is achievable in 20 to 30 years using less than 40% of the proven reserves of conventional petroleum, while supplying sufficient energy to sequester CO2 from the atmosphere using agroec...

In this paper we document two features that have made Saudi Arabia dierent from other oil producers. First, it has typically maintained ample spare capacity. Second, its production has been quite volatile even though it has witnessed few domestic shocks. These features can be rationalised in a general equilibrium model in which the oil market is modelled as a dominant producer with a competitive fringe. We show that the net welfare eect of oil taris on consumers is null. The reason is that Saudi Arabias's monopolistic rents fall entirely on fringe producers. Saudi Arabia is one of the largest players in the global oil market: it produces more than a tenth of the world's oil output and owns a quarter of the world's proven reserves. The Kingdom is also a key OPEC member, typically playing a central role in OPEC's decision-making. Indeed, authors such as Mabro (1975) have gone so far as to claim that 'OPEC is Saudi Arabia'. And according to Adelman (1995), 'the Saudis have acted as what they are: the leading …rm in the world oil market'. Are these claims exaggerations? In this paper we document two features that have made Saudi Arabia dierent from the rest of producers. First, it systematically restricts its production. In fact, its spare capacity is much larger than the aggregate spare capacity of the rest of world producers. Second, its production is quite volatile. The variance of Saudi oil output has been very high compared to that of the rest of producers, even though the Kingdom itself has witnessed few domestic shocks aecting oil production directly. We show that one can rationalise the behaviour of Saudi Arabia as that of a dominant producer with competitive fringe. In the spirit of Salant (1976), we build an industrial organization model into a general equilibrium framework, assuming that the dominant supplier internalises a la Stackelberg the behavioural � Anton Nakov thanks the European Central Bank for its hospitality during the …rst drafts of this paper. The views expressed here are those of the authors and do not necessarily coincide with the views of the the Eurosystem or the Federal

This paper develops a novel approach by which to identify the price of oil at the time of depletion; the so-called ‘terminal price’ of oil. It is shown that while the terminal price is independent of both gross domestic product growth and the price elasticity of energy demand, it is dependent on the world real interest rate and the total lifetime stock of oil resources, as well as on the marginal extraction and scarcity cost parameters. The theoretical predictions of this model are evaluated using data on the cost of extraction, cumulative production and proven reserves. The predicted terminal prices seem sensible for a range of parameters and variables, as illustrated by the sensitivity analysis. Using the terminal price of oil, we calculate the time to depletion and determine the extraction and price profiles over the lifetime of the resource. The extraction profiles generated seem to be in line with the actual production and the predicted prices are generally in line with those currently observed.

A dataset of 25 metrics collected from the 10-Ks of 20 oil and gas operators was segregated into two panels: One with operators with a diversified business strategy (conventional group), and a second with operators focused on shale plays (unconventional group). Under the assumption that through exploration expenses (EXPEX) the cost of geoscientific information can be measured, fixed effects panel regressions with robust standard errors were constructed using proven reserves (P90), and the price per flowing barrel (PFB) as dependent variables, EXPEX as the variable of interest, and a series of controls accounting for other line items expensed in this account. Using the regression coefficients of these regressions the ceteris paribus effect of investments in geoscientific information on P90 and PFB is quantified. According to results, a million dollars invested in the geosciences increases P90 by 304 mboe after four years for operators in the conventional group. For operators in the unconventionals group, results indicate an increment of 935 mboe also after four years. Under an efficient market hypothesis the stock price of an operator should reflect all current available information. Therefore, these increments in proven reserves attributed to investments in geoscience should have a positive impact on the market capitalization of an operator. However, results from PFB models indicate that investments in exploration, even though having an impact on the amount of proven reserves, have a minimal impact on how the market values a barrel of crude from each operator regardless its business strategy.

Petroleum is vital to many industries and in the manufacture of a wide variety of materials; it accounts for a large percentage of the world's energy consumption, and thus is a critical concern for many nations. This chapter gives a general introduction to the petroleum industry. It begins with the terminology, history, composition, classification, and characterization of petroleum (crude oil and natural gas). This discussion is followed by the world’s distribution of petroleum resources and reserves, the types of oil reserves, the world's largest oil and gas companies by proven reserves, and utilization of petroleum. Finally, the petroleum industry sectors (upstream, midstream, and downstream) are introduced along with exploration, development, and production; hydrocarbon processing (refineries and petrochemical plants); storage, transportation, and distribution; and retail or marketing.

The world now relies almost exclusively on petroleum products to power our transportation systems, and coal, natural gas, nuclear and some petroleum products along with a small but growing contribution from renewables for most electricity production. The petroleum dependence is hazardous since approximately 82.6 % of all petroleum proven reserves reside in the twelve OPEC nations (Algeria, Angola, Ecuador, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, UAE, Venezuela) based predominantly in the volatile Middle East. (The ten Middle East and North African nations (excluding Ecuador and Venezuela) still account for 72.2% of all proved petroleum reserves). Coal, on the other hand, is widely distributed around the globe, and natural gas is more widely distributed than petroleum. OPEC nations account for at most 3.7 % of proven coal reserves. We conclude that moving to a global energy system based predominantly on coal instead of petroleum would be far more stable for world security.

Fossil fuel reserves which supplying a major portion of energy needs, are depleting rapidly, and its environmental damages increases day by day. Therefore, like all developed and developing countries, our country have focused on the use of renewable energy sources. Within this scope in the our country, it was aimed gain of renewable energy sources to economy, promotion of sustainable energy production, and protection of environmental. Recently, one of the growing importance of renewable energy sources is the biomass energy. As an biomass energy source, all vegetable and animal organic substances which the main components are comprising carbohydrate compounds can be used. In these energy sources, microalgae seem promising for biofuel production due to their many advantages such as they have high photosynthetic efficiency, high biomass production, and they grow quickly. From microalgae, by using biochemical methods electricity, ethanol, hydrogen, methane and biodiesel and thermochemical methods syngas, biochar, biodiesel and electricity can be produced. In this review article, isolation of microalgae, microalgal biomass production, the methods used to biomass harvesting, and the availability of microalgae as a source of raw materials for renewable biofuels were viewed.

Most economic theories are wrong. Fortunately, most wrong theories are irrelevant. But some wrong theories are relevant. One of these latter theories is Marion King Hubbert’s peak oil theory, postulated in 1956. Hubbert was a geologist who thought that oil exploration is an uncertain undertaking. Frequently, drilling is en vain; in a few cases, gas is discovered and in another few cases oil. Given uncertainty, only proven reserves are said to be reliable. Proven reserves appear as a peak in the known graphs. In lucky times, we find ourselves on the ascending part of the bell-shaped curve. In less favorable times, we slip downward on the descending part of Hubbert’s peak. Oil reserves dwindle and might come to an end. Hubbert’s peak oil theory is still popular, but doubly false: It predicts crises which do not occur and misses to handle crises which occur.

Pyrometallurgical studies conducted for Mn extraction using Turkish Mn-ore reserves were reviewed. Turkish Mn-ores are low-grade ones having ~30% Mn. The most important Mn ore reserves in Turkey are in the Denizli-Tavas region, where more than 2 million tons of proven reserves are reported. Mining rights to the Denizli-Tavas manganese belongs to Eregli Iron and Steel Works Co. (ERDEMIR). The ore is usually charged to the blast furnaces of ERDEMIR during hot metal production. So far, nearly 20 Master’s thesis studies have been conducted for the analysis of manganese extraction in Turkey. In the scope of the present work, only pyrometallurgical and related activities (i.e. ore beneficiation, calcination, etc.) relevent to the treatment of a specific ore were examined.

World increasing population and use of energy for transportation and electricity are demanding more extensive and more efficient use of land for agriculture; aiming to both food and biofuel supplies. This communication assesses the possible improvements in soil fertility, capture of greenhouse gas, and rainfall, as a result of the large scale terrestrial application of pyrogenic carbon aiming for desert greening. Fossil hydrocarbon coke is taken into account for this proposal because of the exhaustion of light petroleum proven reserves that is leading to a scenario of abundant coke production from the processing of non-conventional reserves.

In the traditional energy increasingly tense situation, countries around the world generally give the priority to development of hydropower and vigorously take advantage of water energy resources. China hydropower ranks first in the world whether proven reserves of water energy resources or possible development of water resources. In this paper, from the nature of large hydroelectric energy resources and based on the introduction of the origin, connotation and characteristics of big data, we have analyzed large data hydroelectric energy resources of the road and have given value analysis application prospect of hydropower science large data.

Nigeria ranks as the country with the 7th largest proven reserves of gas globally but currently focuses on the exploration of its oil with little economic use of its gas. The gas is either exported as Liquefied Natural Gas or flared by the oil and gas majors. The government has attempted to minimize the flaring by putting legislations to compel the International Oil Companies (IOCs) to stop the flaring and also encourage the utilization of the gas for electricity generation but the main challenge with this approach has been in the high cost associated with the compression and storage of the gas and the risks of vandalism associated with pipeline transport of the gas. This paper presents an approach for increasing the utilization of the gas for power generation by minimizing the risks associated with vandalization. The Niger Delta which has the bulk of the reserves can become the power generation hub of the country where all the gas driven power generation is done and fed to the national grid through a network of transformers and power lines. This configuration will eliminate the need for long pipelines while enabling the deployment of monitoring technologies on the short lines and also minimize the storage capacity required as the gas produced will be utilized by the generators. It also provides an opportunity for public Privat participation in the power supply sector. This system will ultimately improve the power supply availability in the country.

Polymer gels have been effectively applied to extend the productive life of mature oilfields by mitigating water production and enabling the recovery of bypassed oil reserves. A key component for a successful conformance improvement treatment is the identification of the most appropriate gel technology for a targeted reservoir. Gel projects are capital sensitive and involve high degree of risk; therefore, it is crucial to select a proper gel technology and provide an optimized design project. This paper presents the first generalized comprehensive selection system for injection well gel technologies based on the comparative analyses of the characteristics of conformance problems in gel field projects. 111 field trials of three in-situ gel systems including bulk gels, colloidal dispersion gels, and weak gels were summarized from 1978 to 2015. First, reservoir/fluids characteristics, diagnosis indicators used in the evaluation of drive-fluid channeling strength, and treatment operational parameters were summarized. Then, problem zone volumes were estimated using a design rule of thumb and the problem development status was indicated using some production-related parameters. Finally, all characteristics of conformance problems were compared for different gel systems to identify factors implicitly used in the nomination of gel technologies in the field projects. We recognized that gel selection process starts by matching characteristics of conformance problems with technical specifications and mechanisms of the gel systems. Then, the initial candidate technology is confirmed by screening criteria to ensure gel system compatibilities with reservoir and injected fluids. We identified that the most influential characteristics in the selection process are drive-fluid channeling strength, volume of problem zone, problem development status, existence of cross-flow, and the nature of the required solution whether it depends on gel strength or volume. It was recognized that the existence of crossflow or high oil saturation in the offending zones turns a limited conformance problem into a large volume issue that needs the application of the flood-size treating technologies. For these situations, current oil saturation in the problem zones is the key factor rather than oil saturation in the less conductive zones because it is guaranteed by the high reservoir permeability heterogeneities. In addition, the problem development status does not only affect the selection of a gel system, but also its design parameters such as polymer concentration. The novelty of the new gel selection system is in its utilization of standardized general parameters and provision of distinct parameter cut-offs for each gel technology.

This report provides a review of the Armenian mining sector, and assesses its potential to contribute to sustainable economic growth and development. Based on the findings, it provides recommendations for initiatives and actions for the future development of the sector. The report was produced in the period October 2015 to April 2016. It was commissioned by the World Bank with the aim to assist the Armenian government to gain a better understanding of key social and environmental challenges and future opportunities for the Armenian Mining Sector; and to support the development of a minerals strategy which is line with international good practices and which contributes to sustainable development. The findings are based on: desktop reviews of existing documents; a large number of meetings and interviews with affected and interested stakeholders; field work performed in the main mining districts of Armenia; stakeholder workshops. Comments, suggestions and corrections on a draft version of this report has been provided by representatives of the GoA, and the World Bank. Further, oversight and feedback was continuously provided by representatives of the World Bank.

Today Greece produces and exports raw bauxite and alumina, concentrates of galena and sphalerite and ferronickel. The indicated reserves of bauxite, located in the Mt Helikon-Mt Parnassus-Mt Giona-Mt Iti zone, are estimated at approximately 100 mt and those of aluminum 2.5 mt. The probable and indicated reserves of lead and zinc from Chalkidiki are approximately 3.125 mt. The total production of concentrates of galena and sphalerite is approximately 220,000 tpa. The proven reserves of nickel are approximately 1.392 mt and the production of ferronickel is approximately 18,500 tpa. Production of copper, silver and gold is pending in 2015. The probable and indicated reserves of copper from Skouries Chalkidiki are approximately 1.943 mt. In the Prefecture Units of Chalkidiki and Evros the probable and indicated reserves of gold are approximately 19.37 million ounces and those of silver 131.6 million ounces. Chromium, manganese and molybdenum present good prospects of exploitation. Calculated at current prices, the total gross value of the probable and indicated reserves of the metallic minerals of Greece is €79.4 billion.

The costs associated to the abatement of pollutants coming from the burning of fossil fuels are calculated through the thermodynamic property exergy. We define the clean ton of a fossil fuel as the difference between its maximum recoverable energy (or exergy) and its exergy abatement cost. This way, energy reserves can be expressed in terms of clean tons of oil equivalent, ctoe, instead of the conventional measure expressed as toe. Additionally, the energy content of fossil fuels is affected by the conditions of the environment. An increase in atmospheric CO2 emissions and temperature due to the greenhouse effect, will lead to a decrease in their available energy. Hence, the actual clean tons will take into account both issues, the decrease of exergy due to the utilization of clean technologies plus the climate change effect. In the paper we make an inventory of the clean exergy fossil fuel reserves. The results show that the exergy of proven reserves are decreased by about 11%, if these two factors are taken into account.

Putaohua reservoir in south of Daqing Placanticline is rich in oil and gas resources. However, the distribution of oil and gas is so complex and the hydrocarbon accumulation process is still unclear by now. Due to low proven reserves, it is not effective to explore the reserves. By use of the logging interpretation and results of production test and together with analysis of the oil and gas distribution and hydrocarbon accumulation process of Putaohua reservoir in south of Daqing Placanticline, the controlling factors of hydrocarbon accumulation in aspects of oil and gas migration pathway, developmental characteristics of sand, local structure etc are discussed in order to optimize potential blocks. The hydrocarbon of Putaohua reservoir in both flanks in south of Daqing Placanticline is from the local K1qn1 source rock. Hydrocarbon migration mainly depends on vertical movement and is supported by short-distance lateral migration; hydrocarbon accumulation is mainly affected by restrictions of oil source fault and high fault block, so that most of hydrocarbon accumulate in the distributary channel and distal bar of reverse faulting footwall, horst, reverse fault and other high fault blocks where are closely adjacent to the oil source faults.

article i nfo Article history: I use a stochastic production frontier to model energy ef!ciency trends in 85 countries over a 37-year period. Differences in energy ef!ciency across countries are modeled as a stochastic function of explanatory variables and I estimate the model using the cross-section of time-averaged data, so that no structure is imposed on technological change over time. Energy ef!ciency is measured using a new energy distance function ap- proach. The country using the least energy per unit output, given its mix of outputs and inputs, de!nes the global production frontier. A country's relative energy ef!ciency is given by its distance from the frontier— the ratio of its actual energy use to the minimum required energy use,ceteris paribus. Energy ef!ciency is higher in countries with,inter alia, higher total factor productivity, undervalued currencies, and smaller fossil fuel reserves and it converges over time across countries. Globally, technological change was the most impor- tant factor counteracting the energy-use and carbon-emissions increasing effects of economic growth.

The increasing demand of fossil fuels and decreasing light oil proven reserves lead to a future scenario of abundant coke production from the refinement of non-conventional fossil hydrocarbons. This paper highlights the possibility of using coke as an agrichar for preparing fertile soils resembling Amazonian terra preta. It is suggested that this alternative may contribute to both the capture of greenhouse gas by afforestation and the increase of rainfall by the albedo effect. It is proposed that the ideal agrichar must function as a store of nutrients in the form of graphene substituted NPK groups at the micropore molecular structure, providing habitat for plant friendly microorganism inside its macropores. The possibility of a sink effect connecting nutrient storage with microorganisms has also been proposed. A preliminary discussion on the possible coking procedures to improve the resulting agrichar efficacy, three options for large scale desert greening using agrichar as well as recommendations for further research are presented.

Hydrocarbon Accumulation Coefficient (HAC) is an important parameter in the genetic method of hydrocarbon resource assessment. This parameter is usually derived from a simple geological analogy or from expert judgment based on experience, which can lead to large uncertainties in hydrocarbon resource assessment results. In this article, we introduce a new method for determining the HAC, based on Single Factor Correlation Analysis and Multivariate Regression Analysis, using data collected from basins with a high degree of exploration maturity and large amounts of proven reserves. Firstly, the principal factors that control the hydrocarbon accumulation coefficient, such as the time ratio of peak expulsion and caprock formation, the ratio of maximum fault throw and caprock thickness, and the rate of fault displacement, are determined by Single Factor Correlation Analyses. A quantitative model can then be established between HAC and the principal controlling factors using the Multivariate Regression Analysis. The proposed method was applied to the Huanghekou Sag in Bohai Bay Basin, eastern China. The results show that the HAC is 29% in the Huanghekou Sag, with a total resource of 1435 × 106 m3 oil equivalent, which is consistent with geological observations of this basin and suggests that the proposed method improves the applicability of the generic method in resource assessment.

Oil and natural gas are important energy and chemical raw materials, its resources are gradually reduced. With the rapid development of the global economy, the conventional oil resources can’t meet the rapid growth of oil demand, people began turning to unconventional oil resources, one of which is the oil sands. Oil sands is unconventional oil resources, if its proven reserves are converted into oil, it will be much larger than the world's proven oil reserves. Canadian oil sands reserves stand ahead in the world, followed by the former Soviet Union, Venezuela, the United States and China. However, due to its special properties, different mining and processing technology, and higher mining costs compared with conventional oil, the research of oil sands makes slow progress. At present, due to the rising of world oil price, oil sands mining technology have attracted more and more attention, and have developed a lot.

Mineral resources represent an important natural resource whose exploitation, unless it is rational, can lead to their exhaustion and the collapse of sustainable development. Given the importance of mineral resources and the uncertainty concerning the estimation of extant reserves, they have been analyzed by several national and international institutions. In this article we shall present a few aspects concerning the ways to approach the reserves of mineral resources at national and international level, by considering both economic aspects and those aspects concerned with the definition, classification and aggregation of the reserves of mineral resources by various specialized institutions. At present there are attempts to homogenize practices concerning these aspects for the purpose of presenting correct and comparable information.

Research on Natural Gas Hydrate（NGH）is very popular in recent years. NGH is a potential, new and clean energy with the characteristics of high energy density, high combustion heat, high proven reserves, no pollution, wide distribution and shallow burial and so on. It has been identified that NGH is widely distributed in the plateau, arctic permafrost and some eligible areas in the seabed of epicontinental and continental slope all around the world. According to the research data on NGH at home and abroad, the mineralizing, formation, distribution and exploration technology of NGH are introduced as well as the NGH research status of countries in the world, including China. Many theories and techniques about the exploitation of NGH are not mature yet. Numerous problems still exist in industrial mining NGH, such as environmental, geological problems induced by mining NGH and storage and transportation problems after mining. Finally, the application and mining prospects of NGH are and prospected and summarized to provide a relatively comprehensive reference to this research field.