453 research outputs found

    PRESSURE PREDICTION AND UNDERBALANCED DRILLING IN THE DEEPWATER NIGER DELTA

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    The mechanisms that cause overpressure can be broadly classified into two categories: loading and unloading. This study looks at eight wells from the deepwater Niger Delta; the wells were evaluated with three aims in mind. The first aim was to determine shale pore pressure with the density log using the equivalent depth approach. The second aim, using depth profiles of density, velocity, resistivity, and vertical effective stress, and cross-plots, was to infer the overpressure mechanism. The third aim was to validate underbalanced drilling zones identified on the pressure-depth plot with indications observed on the drilling report, mudlog, and other post-drilling data. To discriminate clean shales intervals, a density-velocity transform based on Gardner’s (1974) relationship and GR filters were applied to the well logs. Measured pore pressures, log data, temperature data, drilling data, and mudlog data, including the end-of-well-report, were analysed for selected wells. Based on pressure-depth plots, the top of overpressure in the wells lies in the range 500 – 1200 TVDml. The equivalent depth method using the density log, when properly calibrated with measured pore pressures, can give reliable pressure prediction results, especially in the shallow section at temperatures 75°C, the equivalent depth method is unreliable. It was also noted that shale intervals may provide vertical permeability barriers and create pressure compartments in some of the wells. The predominant overpressuring mechanism in the shallow section, as evident from density and velocity reversals and, was found to be disequilibrium compaction. At greater depths (temperatures >75°C), a combination of disequilibrium compaction and unloading mechanisms appears to be responsible for overpressure in the wells. Evidence for unloading mechanisms includes formation temperatures of 80°C or greater, indications of smectite-to-illite conversion on density-sonic cross-plots, rapid increases in mud weight that sometimes approached fracture gradient, and depressed density reversals relative to velocity reversals. Finally, intervals identified as being drilled underbalanced on pressure-depth plots are consistent with drilling data, mudlog data, and information in the end-of-well reports. Specifically, increased gas (connection gas and background gas), hole washout, high torque, drilling break, and decreased D-exponent trend show strong association with zones of underbalanced drilling on pressure-depth plots

    Cercetări bibliografice tematice - arhitectură

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    No abstract available. This is a review article

    Ethanol and Biodiesel in Canada: Can They Help Meet Canada's Kyoto Commitment?

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    The Canadian government ratified the Kyoto Protocol in December 2002. The protocol calls for greenhouse gas emissions to be reduced by 6 percent below the 1990 level (approximately 35 percent below what they are expected to be in a business-as-usual situation) by 2008–2012. To help meet this target, both federal and provincial governments in Canada have developed programs (in some cases mandates) for ethanol and biodiesel production and use in fuel blends. Various subsidy schemes have been designed to stimulate development of a biofuels industry in Canada. While the programs have been promoted on the basis of environmental concerns, a major driver has been the search for new markets for Canadian agricultural commodities that face chronically depressed prices. The purposes of this article are to review the current state of policies, programs and production of ethanol and biodiesel in Canada and to assess the prospect of these biofuels to significantly reduce production of greenhouse gases in Canada.Agricultural and Food Policy,

    ELEMENTS OF FRANCHISE AND NETWORK MARKETING IN NORTH AMERICAN ECONOMY

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    There are stories about successes but also about failures referring to franchise and network marketing businesses. Considering the similarities and differences they offer, it is necessary to correctly indicate them for a certain situation. If someone wants to find out the perfect moment for a proper business, he must determine its sense; he must also compare and make a clear difference between its applicability through network marketing or franchise acquisition. There are great stories about success, in both categories, as well as stories of monumental failure and financial loss. A careful analysis and comparison will help one businessman to understand the risks and costs involved; he can also develop the proper opportunity for the unique situation that he turns it into account with specific financial tools. According to the American specialists, network marketing is the “the supreme synergy” as it combines the best parts of the franchise concept with the best parts of the exponential growth. For a clear image, we would like to review the two concepts and the relationships between them. "franchise, network marketing, business, product, service, network distributors.

    DIAGNOSTYKA RÓƻNICOWA ASEPTYCZNEGO I SEPTYCZNEGO OBLUZOWANIA PANEWKI ENDOPROTEZY STAWU BIODROWEGO METODAMI TOMOGRAFII POLARYZACYJNEJ

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    Manuscript contains structural-logical scheme and analytical description of the differential diagnosis of aseptic and septic loosening of the artificial hip joint endoprosthesis using the methods of differential Mueller-matrix mapping of circular birefringence (CB) distributions of polycrystalline synovial films (SF) and results of determining the sensitivity, specificity and accuracy of the wavelet analysis method of differential Mueller-matrix mapping of the distributions of the CB values of polycrystalline films SF patients from the control group and groups with different severity of the hip joint pathology.Manuskrypt zawiera schemat strukturalno-logiczny i opis analityczny diagnostyki rĂłĆŒnicowej aseptycznego i septycznego obluzowania sztucznej endoprotezy stawu biodrowego z wykorzystaniem metod rĂłĆŒnicowego mapowania macierzy Muellera rozkƂadĂłw dwĂłjƂomnoƛci koƂowej polikrystalicznych filmĂłw bƂony maziowej i wynikĂłw okreƛlania czuƂoƛci, swoistoƛci i dokƂadnoƛci metody analizy falkowej rĂłĆŒnicowego mapowania macierzy Muellera rozkƂadĂłw wartoƛci dwĂłjƂomnoƛci koƂowej polikrystalicznych filmĂłw SF pacjentĂłw z grupy kontrolnej i grup o rĂłĆŒnym nasileniu patologii stawu biodrowego
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