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Koo J.M.,SK Energy | Lee H.Y.,Seoul National University | Jeong W.D.,SK Energy | Min D.J.,SK Energy | Yoo H.S.,Korea Ocean Research and Development Institute
72nd European Association of Geoscientists and Engineers Conference and Exhibition 2010: A New Spring for Geoscience. Incorporating SPE EUROPEC 2010

To properly describe subsurface structures in 2D VTI media, we develop a frequency-domain elastic full waveform inversion algorithm based on the cell-based finite-difference modelling technique. For effectively calculating the partial derivative wavefield and accelerating the convergence rate, we use the adjoint state of the wave equation and the new pseudo-Hessian matrix. Since we deal with more elastic constants in the VTI inversion than in the isotropic case, it is more prone to obtain local minimum solutions. To compensate for the weakness of the anisotropic inversion, we couple a few of elastic constants based on Thomsen's relationships between elastic constants and anisotropy parameters. Our coupling method leads to inversion results compatible with true models except for C13. To enhance inversion results for C13, we conduct the waveform inversion at two steps. First we perform either the isotropic or the anisotropic waveform inversion by using linearly increasing models for initial guesses. Then the anisotropic waveform inversion is carried out once more by using the inversion results obtained at the first stage for initial models. By applying these techniques to a part of the 2D overthrust model, we could properly recover the subsurface elastic constants. © 2010, European Association of Geoscientists and Engineers. Source

Nicetic O.,University of Queensland | Cho Y.R.,SK Energy | Rae D.J.,SciEd Solutions
Journal of Applied Entomology

Mineral oils have been historically favoured over plant oils for insect pest control in horticultural crops because of their greater efficacy. Recently the increased pressure for environmentally sustainable pest management strategies has renewed interest in the use of plant oils and also in the reasons for differences in efficacy between plant and mineral oils. Efficacy of canola and mineral oils were compared for two modes of action: asphyxia in control of Saissetia oleae on olives and as an oviposition deterrent in control of Phyllocnistis citrella on lemons. On olives both canola and mineral oil treatments significantly reduced the number of black scale in comparison to the control but mineral oil reduced the number of black scale significantly more than canola oil. When oils were applied to lemons as a preventative spray, concentrations of canola oil above 0.5% significantly reduced the number of P. citrella mines per leaf compared to the control and there were no significant differences between any concentration above 0.5% canola oil and 0.5% mineral oil. Canola oil applied at a concentration of 0.5% was significantly less effective than mineral oil applied at the same concentration. Efficacy of canola oil was found to be lower than that of mineral oil in all experiments, but the higher efficacy of mineral oil was more pronounced in suffocation of S. oleae than in deterrence of P. citrella oviposition. Our results indicate that even though canola oil has very different molecular structures than mineral oils the resulting physical characteristics of canola oil, primarily high boiling point and viscosity, may contribute to their lower efficacy against arthropod pests. However, low phytotoxicity of canola oil indicates that the chemical structure of molecules contained in canola oil had much more influence on processes on the plant surface than the physical characteristics of the oil. © 2010 Blackwell Verlag, GmbH. Source

Tallman M.J.,KBR | Eng C.,KBR | Choi S.,SK Energy | Park D.S.,SK Energy
Petroleum Technology Quarterly

A discussion on KBR'S Advanced Catalytic Olefins process for enabling increased propylene production from straight-run paraffinic feeds covers features of KBR FCC; straight-run paraffin feeds for the ACO process; ACO performance; recovery scheme; the ACO catalyst that was developed by SK Energy that specifically convert naphtha with high yields of propylene and ethylene in a fluid-bed-type reactor; and commercialization of the ACO process. Source

Seok W.,SK Energy | Lee S.-M.,SK Energy
Hydrocarbon Processing

The four case studies cover component failures and multiple types of leakage: valve packing, expansion joint and corrosion. Each case study systematically identifies cause, countermeasures taken and lessons learned. © 2016 Hydrocarbon Processing. Source

Lee S.J.,SK Energy | Lee J.H.,SK Energy | Kim J.N.,Korea Institute of Energy Research | Park J.H.,Korea Institute of Energy Research | Lee J.J.,SK Energy
AIChE Annual Meeting, Conference Proceedings

Many ethylene producers continue to look for competitive sources of ethylene to improve profitability. Although recovery of ethylene in refinery offgases has been practiced for many years, the common approach is to introduce the gas, after feed pretreatment, to the ethylene plant cracked gas compressor. This practice could lead to constraints in the ethylene plant and especially the cold area of the ethylene plant, if the refinery off-gas contains appreciable amount of light ends. SK Energy has recently developed a competitive adsorption process for the economic recovery of ethylene in off-gases. With the use of the Ole-SIV process, up to 95% of the ethylene can be recovered in off-gases with only the use of propylene refrigeration. This highly concentrated ethylene stream can then be introduced well downstream of the ethylene plant, thereby eliminating many of the bottlenecks in the plant compared to more conventional brute force processing. SK Energy is developing the Process Design Package and plans to commercialize in 2013 at its Ulsan Complex, Korea. The ethylene recovered from FCC off-gas by this technology will be used as the feedstock of EB Process. Source

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