813 research outputs found
The New Era in China-U.S. Relations: Economics and Military Security
No full text“The New Era in China-U.S. Relations: Economics and Military Security,” a Great Decisions lecture by Shale Horowitz, professor of political science at UW-Milwaukee
Political alternation as a restraint on investing in influence : evidence from the post-communist transition
No full textThe authors develop and implement a method for measuring the frequency of changes in power among distinct leaders and ideologically distinct parties that is comparable across political systems. The authors find that more frequent alternation in power is associated with the emergence of better governance in post communist countries. The results are consistent with the hypothesis that firms seek durable protection from the state, which implies that expected political alternation is relevant to the decision whether to invest in influence with the governing party or, alternatively, to demand institutions that apply predictable rules, with equality of treatment, regardless of the party in power.National Governance,Governance Indicators,Public Sector Corruption&Anticorruption Measures,Parliamentary Government,Emerging Markets
Oil shale symposia proceedings index: 1964-82
No full textCompiled by Gary L. Baughman and Christopher H. Cox.Includes illustrations.From the Forward: Over the 18 years that the Colorado School of Mines Oil Shale Symposia have been presented in conjunction with the Colorado School of Mines Research Institute (1964-65), the American Institute of Mining, Metallurgical, and Petroleum Engineers (1966-74), and the Laramie Energy Technology Center (1978 to 1982), many volumes of information have been presented on the geology, mining, processing, environmental, and socioeconomic aspects of oil shale development. Although proceedings of each symposium were published, location of specific subject matter has been difficult due to lack of indexes and because titles were listed chronologically only in the table of contents of each proceedings. The results of the symposia, therefore, have not been used as beneficially as the value of the information warrants. This problem now has been eliminated by a comprehensive index that will permit easy access to the materials in the Oil Shale Symposia Proceedings. Dr. Gary Baughman and Christopher Cox have compiled an excellent index of all volumes of the Oil Shale Symposia Proceedings by subject, author, company, and chronological order of presentation, which makes access to the information quick, easy, and convenient. It is their plan to keep the index current by updating it from time to time. This accurate, readily accessible index will be a great convenience to all serious workers concerned with the development of an oil shale industry. We are indebted to them for this contribution--James H. Gary, Editor, Oil Shale Symposium Proceedings, September 24, 1982
Proceedings of the eighth oil shale symposium
No full textQuarterly of the Colorado School of Mines, v.70 no.3.8th Oil Shale Symposium.Includes illustrations, charts, graphs, tables.From the foreword: After over 50 years of predictions that shale oil production in the United States is on the threshold of commercial development, there is still no commercial size plant scheduled for construction. In 1920, technical problems were the main roadblock to commercialization of shale oil production, while today the major obstacles also include environmental and political problems as well as the lack of necessary economic incentives. In spite of the importance of environmental impact with respect to shale oil development, it was a deliberate decision not to include papers on environment in the program of the Eighth Oil Shale Symposium. This decision was made for two reasons: (1) the Seventh Oil Shale Symposium had dealt heavily with environmental and land-use planning, and (2) a survey of companies involved with field work in environmental aspects of oil shale development indicated more complete and definitive papers would be available in the fall of 1975 after another spring and summer of data collection. As a result the decision was made to limit the April meeting to papers that dealt with areas of shale oil production other than environmental and to schedule a special symposium on October 9th and 10th, 1975, restricted to "Environmental Aspects of Oil Shale Development." The need for efficient use and conservation of our energy resources is apparent to everyone today. In the past little attention was paid to energy efficiency of various sources of energy supply and no general ground rules were developed so that true comparisons could be made among energy sources. The keynote session of the Eighth Oil Shale Symposium was devoted to reporting "Input-Output Energy Studies for Development of Oil Shale Resources" and guideline discussions were encouraged. This provided a series of papers on net energy relationships as well as the limitations and restrictions of each of the studies. Hopefully this has given a better insight into the items that should be considered in all net energy studies and their relative importance. Efficient use of other minerals found in oil shale deposits is also a necessary restriction on development of energy sources from oil shale. If properly handled, the recovery of these minerals can help defray part of the costs of mining and land reclamation as well as provide minerals needed for this country's economic progress. Papers are included that pertain to other minerals found with oil shale as well as improvements in technology that will serve to make shale oil production more efficient and less costly. The success of the symposium is due largely to the interest and dedication of the authors of the papers and the support of their employers which permits and encourages them to make the results public. Appreciation is expressed to everyone participating, either as author, speaker or sponsoring company, who made this symposium possible. Special thanks are given to Jon Raese and the reviewer, Mark T. Atwood, who provided prompt and efficient publication of the proceedings. James H. Gary Vice President for Academic Affairs Colorado School of Mine
Water imbibition of shale and its potential influence on shale gas recovery-a comparative study of marine and continental shale formations
No full textA large volume of fracturing fluid is pumped into a well to stimulate shale formation. The water is imbibed into the reservoir during this procedure. The effect of the imbibed water on gas recovery is still in debate. In this work, we study the spontaneous imbibition of water into marine shale samples from the Sichuan Basin and continental shale samples from Erdos Basin to explore the fluid imbibition characteristics and permeability change during water imbibition. Comparison of imbibition experiments shows that shale has stronger water imbibition and diffusion capacity than relatively higher permeability sandstone. Once the imbibition stops, water in shale has stronger ability to diffuse into deeper matrix, the water content in the main flow path decreases. Experiments in this study show that marine shale has stronger water imbibition capacity than continental shale. The permeability of continental shale decreases significantly with increasing imbibition water volume; however, the permeability of marine shale decreases at first and increases after a certain imbibition time. The induced fracture is obvious in the marine shale. SEM analysis shows that the relationship between the clay mineral and organic matter of continental shale is much more complex than that of marine shale, which may be the key factor restricting the water imbibition because the flow path is trapped by swelled clay minerals. Through this study, we concluded that whether gas recovery benefits from water imbibition depends on three aspects: 1) the diffusion ability of liquid into matrix; 2) the new cracks introduced by imbibed water; and 3) the formation sensibility. This study is useful for optimizing fracture fluids and determining the best flow-back method. (C) 2016 Elsevier B.V. All rights reserved
Gas Flow Behavior of Nanoscale Pores in Shale Gas Reservoirs
No full text
The gas transport in shale nanopores is always one of the major concerns in terms of the development of shale gas reservoirs. In this study, the gas flow regimes in shale nanopores were classified and analyzed according to Knudsen number. Then the gas flow model considering Darcy flow, slip flow, transition flow, molecular free flow and adsorption effect was proposed to evaluate the gas flow behavior in shale nanopores. The result shows that the contributions of Darcy flow, slip flow and transition flow in shale nanopores are reciprocal, and are mainly dominated by pore radius and pressure. The adsorption effect greatly influences the total mass flux. The total mass flux will increase as Langmuir pressure and temperature increase while it will decrease with reservoir pressure and the adsorption thickness. These results can provide insights for a better understanding of gas flow in the shale nanopores so as to optimize the production performance of shale gas reservoirs.</p
Quantitative investigation on the characteristics of ions transport into water in gas shale: Marine and continental shale as comparative study
No full textInvestigating ions transport from matrix pores to water is essential for understanding the salinity profiles of shale gas. Previous publications have shown that salt ions can be sourced from the dissolution of precipitated salts and leaching of clay minerals. However, neither a clear standard method nor generally accepted evaluation parameters have been proposed for a quantitative study of the impact and role of these two factors. In this work, a new method based on crushed samples is proposed to avoid the influence of microfractures, and simulate the ions advection and diffusion into water. The characteristic parameters and influencing factors are studied by conducting comparative experiments on sandstone, marine and continental shale samples. The preliminary results showed that it is a credible method to study the impact of precipitated salts and clay minerals. Each transport curve can be divided into three parts: a linear imbibition-diffusion part, non-linear transition part and diffusion part. Three parameters of surface ions density, ions diffusion rate and ions transport capacity can be used for quantitative characterization. Compared with sandstone of relatively higher permeability, shale has a much larger surface ion density and ions diffusion rate, resulting in stronger ions transport capacity. Marine shale has a larger surface ions density than continental shale, suggesting that SID is primarily determined by precipitated salts. However, continental shale has a larger ions diffusion rate than marine shale, leading to a stronger ion transport capacity. It can be explained by more clay minerals in continental shale. Clay minerals that correspond to higher cation exchange capacity and specific surface area can promote faster ion exchange reactions. By comparison with dissolution of precipitated salts, leaching of clay minerals is the dominant mechanism for ion transfer from shale to water. (C) 2017 Elsevier B.V. All rights reserved
Shale Gas Hydraulic Fracturing in the Dutch Posidonia Shale
No full textRecently the oil and gas industry is looking at the Posidonia shale in the Dutch subsurface for production of the unconventional shale gas. This is a form of gas production originating from the U.S.A. After the initial success this gas has become a major energy source in the United States. Shale gas can be present in extremely low permeable shales with high organic content. Through use of hydraulically induced fractures along a horizontal well it is possible to economically produce from these almost impermeable shale formations. Many different completions and techniques have been developed to increase production and enhance profitability. This work presents a survey of the experiences in hydraulic fracturing in the U.S.A., including completions and operations to optimize production. We first review the most important completions, and we identify a number of operations frequently carried out by North American operators to increase production from gas shales. Secondly we identify desirable attributes for shale gas fields, against which a potential project can be scored. Upon review of Posidonia attributes the shale is indeed identified as a potential play, and comparison with three successful American fields provides potentially successful completion and fracturing options. Furthermore this work proposes a reservoir model for the Posidonia shale. Herein the influence of the fracturing parameters fracture density, half-length and conductivity is investigated to determine if common U.S. operations will also be effective in the Netherlands. Based on the simulations we perform an economic evaluation for a Posidonia well in the Netherlands.Petroleum EngineeringGeoscience & EngineeringCivil Engineering and Geoscience
Deep shale oil and gas /
No full textNatural gas and crude oil production from hydrocarbon rich deep shale formations is one of the most quickly expanding trends in domestic oil and gas exploration. Vast new natural gas and oil resources are being discovered every year across North America and one of those new resources comes from the development of deep shale formations, typically located many thousands of feet below the surface of the Earth in tight, low permeability formations. Deep Shale Oil and Gas provides an introduction to shale gas resources as well as offer a basic understanding of the geomechanical properties of shale, the need for hydraulic fracturing, and an indication of shale gas processing. The book also examines the issues regarding the nature of shale gas development, the potential environmental impacts, and the ability of the current regulatory structure to deal with these issues. Deep Shale Oil and Gas delivers a useful reference that today's petroleum and natural gas engineer can use to make informed decisions about meeting and managing the challenges they may face in the development of these resources.Includes bibliographical references and index.Print version record.Natural gas and crude oil production from hydrocarbon rich deep shale formations is one of the most quickly expanding trends in domestic oil and gas exploration. Vast new natural gas and oil resources are being discovered every year across North America and one of those new resources comes from the development of deep shale formations, typically located many thousands of feet below the surface of the Earth in tight, low permeability formations. Deep Shale Oil and Gas provides an introduction to shale gas resources as well as offer a basic understanding of the geomechanical properties of shale, the need for hydraulic fracturing, and an indication of shale gas processing. The book also examines the issues regarding the nature of shale gas development, the potential environmental impacts, and the ability of the current regulatory structure to deal with these issues. Deep Shale Oil and Gas delivers a useful reference that today's petroleum and natural gas engineer can use to make informed decisions about meeting and managing the challenges they may face in the development of these resources.1. Gas and oil in tight formations -- 2. Reservoirs and reservoir fluids -- 3. Gas and oil resources in tight formations -- 4. Development and production -- 5. Hydraulic fracturing -- 6. Fluids management -- 7. Properties processing of gas from tight formations -- 8. Properties and processing of crude oil from tight formations -- 9. Environmental impact.Elsevie
Using graphene to simplify the adsorption of methane on shale in MD simulations
No full textIn this paper we explored material similarity between graphene and shale for methane (CH4) adsorption in the shale gas recovery simulations. The reasons of choosing graphene to model shale have been clarified. Through theoretical analysis we obtained the attenuation law of interaction potential between CH4 and multilayer graphene. It indicates the adsorption energy of CH4 on monolayer graphene is closest to that on shale. The limiting heat of adsorption of CH4 on graphene was calculated by molecular dynamics (MD) simulation. The adsorption isotherms and adsorption heats on the monolayer graphene whose width of the slit pore ranges from 2 nm to 11 nm were calculated by using grand canonical Monte Carlo (GCMC) simulations at different temperatures. The computed adsorption heat is validated by experimental data which indicates that the adsorption properties of CH4 on shale are quite similar with that of CH4 on graphene. Our study may provide a direct evidence of using graphene in modeling shale in simulating the shale gas adsorption/ desorption. (C) 2017 Elsevier B.V. All rights reserved
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