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991.
992.
TOC determination of Gadvan Formation in South Pars Gas field, using artificial intelligent systems and geochemical data 总被引:2,自引:0,他引:2
Mehdi Khoshnoodkia Hassan MohseniOmeid Rahmani Akbar Mohammadi 《Journal of Petroleum Science and Engineering》2011,78(1):119-130
Potentially, TOC content is affected by logging data in a source rock (density, sonic, neutron and resistivity logs). Hence, to analyze these logs, which we make a quick and reliable assessment of a source rock. So, it is a quick and economically cheaper method rather than direct geochemical analysis. A source rock interval poses to less density, lower velocity, higher sonic porosity, higher gamma ray values and increase in resistivity. In this research, Gadvan Formation was studied in two boreholes as potential of source rock. The log data of two wells were used to construct of intelligent models in a source rock of the South Pars Gas field in southwest of Iran. A suite of geophysical logs (neutron, density, sonic and resistivity logs) and cutting chip data samples data were applied for determining TOC content of this formation. Rock-Eval pyrolysis data reveal that Gadvan Formation is poor source rock (less than 0.5%). Hence we attempted a correlation between geophysical data and direct TOC content measurements of using ? Log R, Rock-Eval, neural network and fuzzy logic techniques.The results showed that intelligent models were successful for prediction of TOC content from conventional well logs data. Meanwhile, similar responses from other different intelligent methods indicated that their validity for solving complex problems. 相似文献
993.
S. Saner H. M. Hassan K.A. Al-Ramadan W.M. Abdulghani 《Journal of Petroleum Geology》2006,29(3):257-272
Throughout the subsurface of the Arabian Peninsula, the approximately 460ft thick, Devonian Jauf Formation generally consists of well-compacted, low-porosity sandstones and shales, but it also includes friable and highly porous sandstones which form significant gas and condensate reservoir intervals. The mineralogy and pore properties of these reservoir intervals at the Hawiyah field (part of the giant Ghawar structure) were studied by integrating petrographic data with petrophysical measurements of reservoir sandstone samples.
The reservoir sandstones are mainly composed of quartz arenites containing small amounts of altered potassium feldspar grains, authigenic illite and chlorite. Based on the pore types, which reflect the habits of the intergranular clays, three reservoir sandstone types have been defined: Type A, characterized by macroporosity; Type B, with microporosity; and Type C, with combined laminations of Types A and B. The dominance of pore-lining clay (as in Type A) or pore-filling clay (as in Type B) is the principal factor controlling the petrophysical properties of the samples. Types A and C sandstones contain macro pores, but irreducible water saturation is high (25 to 45%) compared to clean samples elsewhere, because of the presence of micropores associated with clay. In Type B sandstones the irreducible water saturation is commonly greater than 40% because all the pores spaces are in the microporosity range. The irreducible water saturation in Type B sandstones increases rapidly as porosity decreases. When porosity is less than 10%, the corresponding permeability is 0.2 mD, but no economic production can be expected because water saturation is as high as 100%. In the producing intervals, authigenic clays result in low electrical resistivity due to high water saturation; however, water-free gas is produced. 相似文献
The reservoir sandstones are mainly composed of quartz arenites containing small amounts of altered potassium feldspar grains, authigenic illite and chlorite. Based on the pore types, which reflect the habits of the intergranular clays, three reservoir sandstone types have been defined: Type A, characterized by macroporosity; Type B, with microporosity; and Type C, with combined laminations of Types A and B. The dominance of pore-lining clay (as in Type A) or pore-filling clay (as in Type B) is the principal factor controlling the petrophysical properties of the samples. Types A and C sandstones contain macro pores, but irreducible water saturation is high (25 to 45%) compared to clean samples elsewhere, because of the presence of micropores associated with clay. In Type B sandstones the irreducible water saturation is commonly greater than 40% because all the pores spaces are in the microporosity range. The irreducible water saturation in Type B sandstones increases rapidly as porosity decreases. When porosity is less than 10%, the corresponding permeability is 0.2 mD, but no economic production can be expected because water saturation is as high as 100%. In the producing intervals, authigenic clays result in low electrical resistivity due to high water saturation; however, water-free gas is produced. 相似文献
994.
Jan Willem?van?GroenigenEmail author Pieter Jan?Georgius Chris?van?Kessel Eduard W.J.?Hummelink Gerard L.?Velthof Kor B.?Zwart 《Nutrient Cycling in Agroecosystems》2005,72(1):13-25
Studies on emissions of nitrous oxide (N2O) from agricultural soils mostly focus on fluxes between the soil and the atmosphere or are limited to the atmosphere in
the topsoil. However, in soils with shallow water tables, significant N2O formation may occur closer to the groundwater. The aims of this study were (i) to determine the importance of subsoil N2O formation in a sandy soil; and (ii) to obtain a quantitative insight in the contribution of subsoil N2O to the overall losses of N2O to the environment. We applied 15N labeled fertilizer at a rate of 5.22 kg 15N ha−1; 50% as Ca(NO3)2 and 50% as NH4Cl, on a mesic typic Haplaquod seeded with potatoes (Solanum tuberosum L.), and traced soil N2O concentrations and fluxes over a one-year period. Throughout the year, total N2O and the amount of 15N recovered in soil N2O were highest in the subsoil, with a maximum concentration at 48 cm depth in mid-February of 19900 μl m−3 and 24 μg 15N m−3, respectively. The maximum concentration coincided with the highest water-filled pore space of 71%. The cumulative flux of
N2O was 446 g N2O-N ha−1, the recovery of 15N in this flux was 0.06%. During the summer, maximum fluxes followed high soil N2O concentrations. During winter, no such relation was found. We concluded that the formation of N2O was the highest in the subsoil, largely controlled by water-filled pore space rather than NO3− concentration or temperature. Although high subsoil N2O concentrations did not lead to high surface fluxes of N2O in the winter, artificial draining may lead to high indirect N2O emissions through supersaturated drainage water. 相似文献
995.
Andrew J. Morris Rebecca J. Nicholls Chris J. Pickard Jonathan R. Yates 《Computer Physics Communications》2014
We present OptaDOS, a program for calculating core-electron and low-loss electron energy loss spectra (EELS) and optical spectra along with total-, projected- and joint-density of electronic states (DOS) from single-particle eigenenergies and dipole transition coefficients. Energy-loss spectroscopy is an important tool for probing bonding within a material. Interpreting these spectra can be aided by first principles calculations. The spectra are generated from the eigenenergies through integration over the Brillouin zone. An important feature of this code is that this integration is performed using a choice of adaptive or linear extrapolation broadening methods which we show produces higher accuracy spectra than standard fixed-width Gaussian broadening. OptaDOS may be straightforwardly interfaced to any electronic structure code. OptaDOS is freely available under the GNU General Public licence from http://www.optados.org. 相似文献
996.
997.
The aim of this study is to further establish the validity and reliability of the Dula Dangerous Driving Index (DDDI). The reliability and validity of the instrument was investigated by comparing data from a US university sample, a US community sample, and a sample of Belgian traffic offenders. Exploratory and confirmatory factor analysis supported the presence of a four-factor structure with items for Drunk Driving forming a separate scale apart from items for Risky Driving, Negative Cognitive/Emotional Driving and Aggressive Driving. A multi-group confirmatory factor analysis with model constraints supported the validity of the DDDI. Inter-correlations revealed that the DDDI subscales are closely interrelated and uni-dimensionality of the measure was found in all three samples. This suggests the DDDI Total score can be used as a composite measure for dangerous driving. However, the validity of the subscales was demonstrated in the Belgian sample, as specific traffic offender groups (convicted for drunk driving, aggressive driving, speeding) scored higher on corresponding scales (Drunk Driving, Aggressive Driving, and Risky Driving, respectively), indicating that it is clinically meaningful to differentiate the subscales. 相似文献
998.
Xiaoyu Li Thomas Scott Chris Cromer David Cooper Steven Comisford 《Journal of research of the National Institute of Standards and Technology》2007,112(5):283-286
We report the results of a high-energy laser calorimeter comparison conducted by the National Institute of Standards and Technology (NIST), Boulder, Colorado and the U.S. Air Force Primary Standards laboratory (AFPSL), Heath, Ohio. A laser power meter, used as a transfer standard, was calibrated at each laboratory, sequentially, and the measurement results were compared. These measurements were performed at a nominal power of 800 W and a wavelength of 10.6 μm using CO2 lasers. Excellent measurement agreement (1.02 %) was demonstrated, which was well within each of the expanded uncertainties from the two laboratories involved in this comparison. 相似文献
999.
Terry Wall Yinghui Liu Chris Spero Liza Elliott Sameer Khare Renu Rathnam Farida Zeenathal Behdad Moghtaderi Bart Buhre Changdong Sheng Raj Gupta Toshihiko Yamada Keiji Makino Jianglong Yu 《Chemical Engineering Research and Design》2009,87(8):1003-1016
Oxyfuel combustion is seen as one of the major options for CO2 capture for future clean coal technologies. The paper provides an overview on research activities and technology development through a fundamental research underpinning the Australia/Japan Oxyfuel Feasibility Project. Studies on oxyfuel combustion on a pilot-scale furnace and a laboratory scale drop tube furnace are presented and compared with computational fluid dynamics (CFD) predictions. The research has made several contributions to current knowledge, including; comprehensive assessment on oxyfuel combustion in a pilot-scale oxyfuel furnace, modifying the design criterion for an oxy retrofit by matching heat transfer, a new 4-grey gas model which accurately predicts emissivity of the gases in oxy-fired furnaces has been developed for furnace modelling, the first measurements of coal reactivity comparisons in air and oxyfuel at laboratory and pilot-scale; and predictions of observed delays in flame ignition in oxy-firing. 相似文献
1000.