The Evolution of Giant Oil Field Production Behavior

The giant oil fields of the world are only a small fraction of the total number of fields, but their importance is huge. Over 50% of the world’s oil production came from giants by 2005 and more than half of the world’s ultimate reserves are found in giants. Based on this, it is reasonable to assume that the future development of the giant oil fields will have a significant impact on the world oil supply. In order to better understand the giant fields and their future behavior, one must first understand their history. This study has used a comprehensive database on giant oil fields in order to determine their typical parameters, such as the average decline rate and life-times of giants. The evolution of giant oil field behavior has been investigated to better understand future behavior. One conclusion is that new technology and production methods have generally led to high depletion rates and rapid decline. The historical trend points towards high decline rates of fields currently on plateau production. The peak production generally occurs before half the ultimate reserves have been produced in giant oil fields. A strong correlation between depletion-at-peak and average decline rate is also found, verifying that high depletion rate leads to rapid decline. Our result also implies that depletion analysis can be used to rule out unrealistic production expectations from a known reserve, or to connect an estimated production level to a needed reserve base.     

Encircling the Peak of World Oil Production

Natural Resources Research - The peak of world oil production, followed by an irreversible decline, will be a watershed in human history. The goal of this paper is to predict the world peak....     

North American Natural Gas: Data Show Supply Problems

Natural gas is increasingly the fuel of choice for domestic and industrial use and for electric power generation. With pipelines in all 50 states, gas now fuels more than one-half of United States homes. Demand for all uses is projected to rise. United States production peaked in 1971, and is in decline. The United States in 2002 imported 15% of its gas from Canada, which amount was 56% of Canada's production. However, Canada's production now also is in decline. Mexico's production declined from 1999 to 2002 against rising demand. Mexico is increasingly a net gas importer from the United States. In both the United States and Canada, intensive drilling is being offset by high depletion rates. Frontiers for more production include deep basin drilling, improved exploration and reservoir development technology, increased coalbed methane exploitation, and access to lands not now accessible because of environmental and other restrictions. Stranded gas in Arctic regions of the United States and Canada offer some potential for additional supplies, but pipeline access is at least five years to ten years or more away. Additional LNG landing facilities are needed, and are planned, but these are several years away in significant numbers. For the immediate future, rationing of available gas by the market mechanism of higher prices seems the only option. In the longer term, it seems North America will be increasingly dependent on LNG.     

A Scenario-Based Hydrocarbon Production Forecast for Louisiana

Conventional oil and gas productions in Louisiana has been in decline for four decades, but in recent years, new technology and capital investment have opened up a significant new resource play in the Haynesville shale, reversing Louisiana’s gas production decline. The need for long-term forecasting has become more important for state planning and for facilitating efficient regulatory development and incentive programs, as the largest oil and gas fields diminish in productivity and the promise of unconventional resources are realized. The purpose of this article is to present a hydrocarbon production forecast for Louisiana using disaggregate resource classes and a transparent analytic framework. A field-level evaluation is employed for producing fields categorized by primary product, resource category, geographic area, and production class. Undiscovered fields are classified according to conventional and unconventional categories and are modeled using a probabilistic and scenario-based forecast. The analytic framework is described along with a discussion of the model results and limitations of the analysis. Louisiana is in the early stages of transitioning to a primarily gas-producing state, and the manner in which the Haynesville shale develops will play a critical role in deliverability and economic prospects in the future.     

石羊河下游民勤绿洲变化的人文机制研究

本文根据社会调查资料分析了甘肃省河西地区石羊河下游民勤绿洲变化的趋势及其影响 ,进而从用水行为和水量均衡角度讨论了绿洲变化的人文作用机制 ,认为石羊河流域下游绿洲变化与传统农业外延式扩张机制密切相关 ,而传统农业扩张机制由于各种因素的制约在短时期内难以打破。而不打破导致绿洲环境恶化的人文机制 ,任何试图扭转此类地区绿洲环境恶化趋势的措施都可能是无效的。     

An assessment of oil supply and its implications for future prices

This paper examines three issues related to both the U.S. and world oil supply: (1) the nature of the long-term, postpeak production profile for the U.S. and, by inference, other regions (the Hubbert curve is used as a “strawman” model); (2) implications on U.S. energy security of using a modified Hubbert-type conceptual model of prepeak production, testing the adequacy of Latin America to be the primary source of U.S. oil imports; and (3) the cyclic behavior of oil prices. it shows that U.S. production will exhibit a more attenuated decline than that simulated by the Hubbert curve and not decline to zero. it asserts that U.S. production is better predicted by past reserves than past production, but that this argument does not apply to nations that keep a much larger proportion of reserves in the ground. Such nations could considerably expand production without any growth in reserves. The paper concedes that the potential total production for these nations could be examined with a Hubbert curve model linked to reserves, but with great uncertainty. Such an uncertain optimistic forecast predicts that the cumulative production of Latin America could far exceed that of the United States. Nevertheless, a statistical model of oil prices since 1870 implies that real wellhead oil prices in the United States are on a long-term upward path, underlying a much more “noisy” cyclical pattern estimated to include 22- and 27-year cycles. The statistical model predicts a severe oil shock within a few years (of 1998) but also predicts that through 2030, real oil prices will not reach 1981 levels again. The paper examines U.S. and world trends in seismic exploration, drilling locations and depths, drilling costs, oil/gas reserves, oil/gas use rates, and oil demand. After taking these factors into consideration, it concludes that the statistical model of oil prices cannot be disputed, despite its lack of basis in economic theory.     

太湖流域土地利用变化对耕地生产力的影响研究

以城镇化过程持续加速而耕地流失及粮食供需形势日趋严峻的太湖流域为研究区,结合遥感、土壤、气象及农业统计数据,借助AEZ模型和GIS开展1985~2010年土地利用变化对耕地生产力的影响分析及评价。结果表明：① 流域耕地生产力水平较高,高产耕地分布广泛;② 近30 a来就地城镇化和工业化发展导致流域建设用地快速扩张,耕地数量锐减;③ 由于减少的多为城市周边及交通沿线水土条件优越的优质耕地,新增的则多是来源于土地复垦或整理的低产耕地,“高产耕地锐减-低产耕地缓增”导致流域耕地生产力水平下降,且在不同发展阶段下降格局不同;④ 高产田锐减导致流域粮食大幅减产,不同县域由于经济发展水平和耕地利用条件不同,粮食减幅呈现显著空间差异。     

中国耕地利用集约度结构变化及其区域差异

Based on the data from the Cost-benefit Data of Farm Produce and the China Agricultural Yearbook, this paper divided the intensity of cultivated land use into labor intensity and capital intensity, and then analyzed their temporal and spatial change at both national and provincial levels between 1980 and 2006. The results showed that: (1) At the national level, labor intensity on food produce decreased from 398.5 day/ha in 1980 to 130.25 day/ha in 2006; and a continuous decrease with a steep decline between 1980 and 1986, a slower decline from 1987 to 1996, and another steep decline from 1997 to 2006. On the contrary, capital intensity shows an increasing trend since 1980. As to the internal composition of capital intensity, the proportion of seed, chemical fertilizer and pesticide input decreased from 90.36% to 73.44% and the proportion of machinery increased from 9.64% to 26.56%. The less emphasis on yield-increasing input and more emphasis on labor-saving input are the main reasons for a slow increase of yield per unit area after 1996. (2) At the provincial level, the developed areas have lower labor intensity and higher capital intensity. The less developed ones have higher labor intensity but lower capital intensity. From the viewpoint of the internal composition of capital intensity, labor-saving input accounts for more proportion in the developed areas than that of other areas. The main reason is that in these developed areas, labor input has become a constraint factor in food production as more and more labors engaged in off-farm work. Farmers increase the labor-saving input for higher labor productivity. However, in the less developed areas, the major constraint is the shortage of capital; food production is still depending on labor and yield-increasing inputs.     

Structural change of agricultural land use intensity and its regional disparity in China

Based on the data from the Cost-benefit Data of Farm Produce and the China Agricultural Yearbook, this paper divided the intensity of cultivated land use into labor intensity and capital intensity, and then analyzed their temporal and spatial change at both national and provincial levels between 1980 and 2006. The results showed that: (1) At the national level, labor intensity on food produce decreased from 398.5 day/ha in 1980 to 130.25 day/ha in 2006; and a continuous decrease with a steep decline between 1980 and 1986, a slower decline from 1987 to 1996, and another steep decline from 1997 to 2006. On the contrary, capital intensity shows an increasing trend since 1980. As to the internal composition of capital intensity, the proportion of seed, chemical fertilizer and pesticide input decreased from 90.36% to 73.44% and the proportion of machinery increased from 9.64% to 26.56%. The less emphasis on yield-increasing input and more emphasis on labor-saving input are the main reasons for a slow increase of yield per unit area after 1996. (2) At the provincial level, the developed areas have lower labor intensity and higher capital intensity. The less developed ones have higher labor intensity but lower capital intensity. From the viewpoint of the internal composition of capital intensity, labor-saving input accounts for more proportion in the developed areas than that of other areas. The main reason is that in these developed areas, labor input has become a constraint factor in food production as more and more labors engaged in off-farm work. Farmers increase the labor-saving input for higher labor productivity. However, in the less developed areas, the major constraint is the shortage of capital; food production is still depending on labor and yield-increasing inputs.     

Preference for Grassland Heterogeneity: Implications for Biodiversity in the Great Plains

The Great Plains of the United States is a grassland region managed primarily for homogeneity associated with production agriculture. The resulting decline of obligate fauna makes enhancing biodiversity an increasingly important ecological goal. A survey was administered to land managers and the general population in ranching regions of Nebraska, Kansas, Oklahoma, and the Texas Panhandle. This research explores the preferred characteristics of privately owned grasslands among ranchers and the general population for vegetation structure and biodiversity. Results indicate a knowledge gap between biodiversity and the vegetation heterogeneity required to support it. Preference for grassland structure is seen as a sociocultural driver of decisions on management practices that constrain adoption of heterogeneity management. Conserving biodiversity and enhancing ecosystem services provided by heterogeneous grasslands can be accomplished by demonstrating that conservation advantages of heterogeneity and production agriculture are compatible.     

A New Model for the Lifetime of Fossil Fuel Resources

A critical examination of Hubbert’s model proves that it does not account for several factors that have significantly influenced the production of petroleum and other fossil fuels. The effect of these factors comes into the price of the fossil fuels, and the latter has a significant influence on the demand and rate of production of energy resources as well as on the long-term rate of production growth at both the regional and global levels. Based on several observations of historical production data, a simple mathematical model is constructed and presented in this paper for the lifetime of a fossil fuel resource. The recent data of global petroleum and natural gas production show that a very important period in the life of energy resources is a period when the demand of these resources increases almost linearly. The linear part of the production curve makes the entire lifetime production of the resource asymmetric. Information on the total available quantity of a resource at any time and of the average slope during this linear period yields an estimate of the timescale, T ₂, when peak production is reached and depletion follows. The total available quantity of the energy resource is laden with significant uncertainty, which propagates in the estimates of the timescale of the peak production in any resource model. The time asymmetry of the current model leads to a delay of the timescale, when the onset of the resource production commences (e.g., peak oil). However, the rate of the resource production decline is significantly higher than that predicted by other models that use a symmetrical curve-fitting method.     

基于系统动力学的新冠肺炎疫情影响北京经济发展的模拟仿真分析

运用系统动力学方法,以北京市为例,通过多情景设置模拟COVID-19疫情对北京经济发展的影响;并对不同政策干预效果进行仿真分析。研究表明：① 分行业来看,COVID-19疫情对交通运输业的直接影响来自于出行管制,需求锐减和相关限制措施导致行业在短期内增长乏力;租赁与商务服务业需求不会随着疫情管控措施解除而立刻增加,行业复苏有一定的时滞;受其他行业复苏延迟影响,金融业发展的低迷时期会更长;复工复产的有序推进加速了工业和建筑业发展,有利于增强其对保持经济稳定的贡献。② 从整体来看,新冠肺炎疫情暴发在短期内使得北京经济下行压力增大,各种管制措施出台和需求萎缩会进一步降低经济增速。然而,随着疫情蔓延得到有效遏制和复工复产步伐加快,COVID-19疫情对北京经济发展的不利冲击会大幅降低。③ 从政策干预效果来看,解除企业生产和经营活动限制所引起城市经济发展水平的提升幅度大于财政对相关产业的补贴;而2种政策组合干预会进一步降低因COVID-19疫情暴发而对经济带来的不利影响,避免经济出现滑坡。模拟结果符合北京市2020年经济发展实际情况,验证了模拟方法的有效性。     

Predicting the Peak in World Oil Production

The US Department of Energy's Energy Information Administration (EIA) recently predicted that world oil production could continue to increase for more than three decades, based on the recent US Geological Survey (USGS) evaluation of world oil resources and a simple, transparent model. However, it can be shown that this model is not consistent with actual oil production records in many different regions, particularly that of the US, from which it was derived. A more careful application of the EIA model, using the same resource estimates, indicates that at best non-OPEC oil production can increase for less than two decades, and should begin to decline at the latest sometime between 2015 and 2020. OPEC at this point will completely control the world oil market and will need to meet increased demand as well as compensate for declining production of non-OPEC producers. OPEC could control the market even sooner than this, given its larger share of proven oil reserves, probable difficulties in transforming non-OPEC undiscovered reserves into proven reserves, and the converging interests of all oil producers as reserves are depleted. This has significant implications for the world economy and for US national security.     

CHANGES IN AGRICULTURAL PRODUCTION IN METROPOLITAN AREAS *

Different types of farming in metropolitan areas show both negative and positive responses to urban and nonurban forces of change. The variety of impacts has been neglected by most spatial intensity models and land use studies. This study examines census data from 1949 to 1982 in seven major U.S. metropolitan areas for six commodity types to detect regular patterns of changes in sales value, area harvested, number of animals, and intensity of production. Results show large declines in dairy farming, followed by poultry and fruit and nuts; some recent recovery in vegetable crops; and steady increases in both low value field crops and high value horticultural specialties. A trend toward polarization of metropolitan agriculture is indicated. Results also show differences between inner and outer urban fringe areas and a decline in the differential in intensity of production between metropolitan and non-metropolitan agriculture.     

外资企业的环境溢出对内资企业污染排放强度的影响

在中国全面对外开放和可持续发展的背景下,本文从微观尺度探究了外资企业集聚的环境溢出效应。利用1999—2012年中国工业企业污染数据库和中国工业企业数据库,本文对比了外资和内资企业二氧化硫和化学需氧量排放强度的时空差异和演变过程,并建立计量模型探究外资企业的环境溢出效应及其作用途径。研究发现：① 在研究时段内,中国工业企业的二氧化硫和化学需氧量排放总量呈现逐渐下降的趋势,该现象来源于内资企业排放总量的下降,而外资企业的排放总量未发生明显变化。② 内资企业的二氧化硫和化学需氧量排放强度迅速下降,并逐渐接近外资企业的排放强度。中国内资企业二氧化硫和化学需氧量排放强度较低的区域主要分布在沿海经济发达的地区,而内陆地区的排放强度下降幅度较大。③ 实证结果表明,无论是产业内还是产业间,外资企业的地理集聚均能够显著降低内资企业的污染排放强度,但是产业内溢出的作用比产业间的溢出更显著。外资企业的环境溢出效应可以通过三条途径作用于内资企业,分别是劳动力流动、竞争效应和本地生产网络的嵌入。在本地生产网络的嵌入方面,后向效应能够产生环境溢出效应,而前向效应并不显著。从异质性分析来看,相对于高效率的企业,低效率的企业仅能够从劳动力流动或本地生产网络嵌入中获取环境溢出的外部性。     

水平衡下黄淮海平原区耕地可持续生产能力测算

为缓解黄淮海平原区地下水水位的持续下降,国家提出耕地资源休养生息的战略,而实施耕地资源休养生息的关键,是确保水平衡下的耕地资源可持续生产能力。本文从可持续理论和水平衡的条件出发,将黄淮海划分成12个自然条件、社会经济条件相对均一的农业生态区,采用不同农业生态区代表实验站限水高产的产量和管理经验,以水定产并逐步修正,得到了黄淮海平原区耕地可持续生产能力,并与现实产量对比得到产量差。结果表明：① 水平衡条件下黄淮海平原区耕地的可持续粮食生产能力为1.16亿t/年;② 可持续总产产量差为-67.85万t/年,由于限水灌溉造成的粮食产能损失为小麦331.84万t/年,玉米不存在产能损失;③ 小麦主要压产地区为黑龙港地区、鲁西平原、豫东平原以及京津唐平原,而徐淮低平原、豫东平原以及胶西黄泛平原具有一定的提产潜力。通过测算,进一步认识了黄淮海平原区耕地可持续产能状况,为区域粮食生产的合理布局以及农业限水限产提供可靠依据。     

Trouble in paradise: resilience and Vancouver’s second life in the “new economy”

Resilience is an increasingly important concept within urban studies, economic geography, and evolutionary economics for measuring the capacity of city-regions to respond to economic shocks. In this article, we provide a sympathetic critique of the resilience metaphor in urban studies, which we explicate through an analysis of the recent history of the Vancouver economy. On the surface, Vancouver seemingly showed resilience when it overcame the abrupt decline of its resource-based economy in the 1980s, and established an alternative flourishing “new economy” by the 1990s. But over the last five years, the key local “creative” industries such as video game development and film production have suffered, with a number of large firms leaving Vancouver, and industry employment declining sharply. Drawing on more than 40 interviews conducted over a five-year period with members of the local video game community, our paper documents the rise and more recent decline of Vancouver’s “new economy” sector. Our research raises questions about the value of the resilience metaphor in urban studies and highlights the difficulties facing city-regions reliant on highly mobile “new economy” industries.     

湖北省经济增长因素贡献率分析

改革开放以来,科技进步在经济增长中的贡献越来越不容忽视。利用1991~2009年湖北统计年鉴相关数据,运用产出增长型生产函数模型,研究各因素对湖北省经济增长的贡献程度,发现近20年来,技术进步与投资对于湖北省经济增长的贡献存在彼此消长的趋势,且投资依然是经济增长的主要动力;劳动力贡献逐渐降低,科技进步对经济增长的贡献不高,呈不稳定态势。     

底特律汽车产业转型失败及启示

随着世界进入全球化时代以及信息技术的广泛应用,工业发展的自身特点和外部环境都发生了变化,转型升级成为新的主题。底特律是美国重要的工业城市,本文通过研究其汽车产业发展从辉煌走向衰落的过程,认为底特律自然条件和区位环境都非常优越,在福特制生产方式主导的时期,曾拥有"全球汽车制造中心"的辉煌。当面对外部竞争激烈、要素成本领先的区位条件吸引力减弱、生产和消费市场环境改变等因素下,由于地方文化强烈的优越感而自我封闭和路径依赖过度导致创新锁定,最终产业转型失败而衰落成无人问津的城市。底特律产业转型失败的教训对于我国城市的产业升级具有良好的警示作用。     

Learning Conservation: the role of conservation covenants in landscape redesign at Project Hindmarsh,Victoria

Biodiversity decline continues apace across the Australian landscape with a pressing need to redesign land use to address this situation. The significance of private land increasingly is recognised for the protection and enhancement of biodiversity as landholders inevitably make decisions that affect environmental quality. Biodiversity conservation is as much a social process as a physical one. Conservation covenants are perpetual agreements under which landholders choose to conserve land voluntarily, primarily for conservation purposes. The role covenants might play in landscape-scale conservation was investigated in north-western Victoria. In-depth interviews with a range of participants were undertaken, with an emphasis on the role covenantors might play as social learning and cultural change agents. Analysis of these interviews offers useful perspectives for understanding socio-cultural dimensions of landscape change and exploring the differing values of production farmers and nature conservation landholders. Consideration is then given to approaches to engaging local production farmers in nature covenants and promoting communication between this group and the largely non-production conservationists who currently form the mainstay of conservation covenants.