A Model for Resource Assessment and Exploration/Production Production

Over the last few years, many studies (WAES, WEC, CIA, oil companies, etc.) have popularized the idea that world oil production will reach a maximum in the 1980's or 1990's and progressively decline. If cumulative production up to the maximum is calculated and compared to the remaining resources to be recovered or produced (taken from the WEC Delphi Study, for instance) it is possible to assume other types of evolution for world oil production as well, in particular a plateau extending over a few decades. Because of the continuing importance of oil in the world economy, such an evolution would be far more desirable than a prompt decline. But of course it is important to assess whether this is even possible and/or realistic. The IREP model (IIASA Resources, Exploration and Production model) has essentially been designed, in the initial version which is presented here, to explore such a possibility. Preliminary ideas for the resource model came from the Enerdym model (which was developed with Igor Zimin), especially the conceptual aspects of describing the "life" of a resource, from its initial status of "speculative resource" to its possible production. The IREP model is composed of a number of submodels: resource assessment (the most developed to date), an exploration submodel primarily aimed at obtaining an idea of the effort necessary (drilling, investment, etc.) to discover the assumed resources, and a production submodel directly linked to the exploration submodel but allowing the examination or various scenarios influenced by politico-economic decisions. In addition, the IREP model can also be used as a sensitivity analysis tool to explore how changes in some parameters -- generally linked to the progress of exploration and/or knowledge of petroleum prospects or basins -- can influence oil resources and their future production potential. As such, this model is not only a tool which can be used in a preliminary way for forecasting or assessing, but also a working tool for enabling a better understanding of world oil assessment. The resource assessment submodel has been developed in detail and tested with an application case. Results -- although preliminary -- are encouraging, and it was thought that this work could usefully be presented and offered for discussion. The input data for the application case will be refined, and more importance should be attached to the potential validity of the approach than to the first results, shown here in a sample run

A Bayesian Procedure for Resource Evaluation of Petroleum Provinces in the Early Stages of Exploration

A major open problem in quantitative methods for petroleum resource evaluation concerns the provision of statistical techniques for geological provinces in the early stages of exploration-for example, if all exploratory wells drilled to date have been found to be dry or if only a few fields have been discovered. A considerable body of literature exists concerning statistical methods for mature provinces in which discovery volumes are on a general declining trend; all these methods use exploration history within the province to project total petroleum resources. In the early stages of exploration however, historical data is an insufficient basis for resource estimation and a simple method must be found to transfer relevant information from explored provinces with similar geology. Following a survey of the existing quantitative methods for petroleum resource evaluation, this paper describes a new method for Bayesian updating of discovery probabilities corresponding to a rough field size classification in the light of current dry hole data. It is based on spatial Poisson dry hole sampling distributions fitted to geologically similar provinces. The method is applied to and the underlying assumptions statistically tested on some typical partly-explored provinces in Brazil. Finally, a Monte Carlo method for the resource assessment of immature provinces, based on revised discovery probabilities and building on earlier work (Medova, 1980) will be suggested for future development

Nitrogen and phosphorus limitation of oceanic microbial growth during spring in the Gulf of Aqaba

Bioassay experiments were performed to identify how growth of key groups within the microbial community was simultaneously limited by nutrient (nitrogen and phosphorus) availability during spring in the Gulf of Aqaba's oceanic waters. Measurements of chlorophyll a (chl a) concentration and fast repetition rate (FRR) fluorescence generally demonstrated that growth of obligate phototrophic phytoplankton was co-limited by N and P and growth of facultative aerobic anoxygenic photoheterotropic (AAP) bacteria was limited by N. Phytoplankton exhibited an increase in chl a biomass over 24 to 48 h upon relief of nutrient limitation. This response coincided with an increase in photosystem II (PSII) photochemical efficiency (F v /F m), but was preceded (within 24 h) by a decrease in effective absorption crosssection (σPSII) and electron turnover time (τ). A similar response for τ and bacterio-chl a was observed for the AAPs. Consistent with the up-regulation of PSII activity with FRR fluorescence were observations of newly synthesized PSII reaction centers via low temperature (77K) fluorescence spectroscopy for addition of N (and N + P). Flow cytometry revealed that the chl a and thus FRR fluorescence responses were partly driven by the picophytoplankton (æ10 μm) community, and in particular Synechococcus. Productivity of obligate heterotrophic bacteria exhibited the greatest increase in response to a natural (deep water) treatment, but only a small increase in response to N and P addition, demonstrating the importance of additional substrates (most likely dissolved organic carbon) in moderating the heterotrophs. These data support previous observations that the microbial community response (autotrophy relative to heterotrophy) is critically dependent upon the nature of transient nutrient enrichment. © Inter-Research 2009

Research Library's Role and Place in the Educational Environment of Pedagogical University

The paper provides some results of the library reader survey which allowed establishing the new role and place of the research library of a pedagogical university. The creative role of the research library determines the possible options of interaction between the library and scientific and educational departments of the pedagogical university. In the educational environment, the library becomes a “third place” between home and classroom

Chance-Constrained Stochastic Programming for Integrated Services Network Management

this paper we formulate a model which aims to combine results on the probabilistic analysis of congestion in the network with optimisation of traffic routing decisions. The optimization model is essentially deterministic multicommodity network flow accounting for the stochasticity of traffic flows in the constraints. In this introduction a brief account of modern technology is given for the purpose of explaining the modelling assumptions. The derivation of a measure of stochastic multi-service traffic is presented in Section 2. Section 3 treats model formulation and implementation. Section 4 discusses model implementation and a simple numerical example. Conclusions and future research directions are contained in Section 5. Emerging from telephony, B-ISDN will carry different traffic such as voice, data and video over the same bearer. A standardised transport, multiplexing and switching technique called Asynchronous Transfer Mode (ATM) is recommended as a common digital format for implementing the B-ISDN concept. The resource model of an ATM network considers demands with very different statistical properties requiring flexible allocation of resources. For example data transmission services are highly bursty (burstiness = peak bit rate / average bit rate), whereas high definition television (HDTV) distribution has low burstiness but will consume a bit rate above 50 Mb/s per HDTV channel.All information coming from different traffic sources is transmitted by the means of short fixed length cells comprising a 5 byte header and a 48 byte information payload. The process of resource allocation in ATM networks exploits statistical multiplexing and is associated with some form of traffic usage contract. The notion of a committed quality or Grade of Service (GoS) per connection..

Research Papers

Risk management has often consisted of managing different types of risk separately as a consequence of the traditional internal bank organisation by asset class groups. However, the limitations of this segregated approach have increasingly become recognised, and many firms are now looking to use enterprise-wide risk management systems that integrate different types of risk into one framework. A framework underlying several models that measure the credit risk of a portfolio is extended in this paper to allow the integration of market risk and credit risk. Using a Monte Carlo methodology, the proposed integrated framework calculates a distribution for the value of a portfolio at a series of future time horizons. To reduce some of the data deficiencies that continue to be prevalent, particularly with the credit quality of firms, the proposed implementation of the framework uses market data where possible. Default probabilities are calculated using a structural model where some of the key parameters are estimated from equity data. As an illustration, the model developed in this paper is applied to a foreign exchange forward where there is a significant probability of default by the counterparty