NMR relaxation and diffusion characterization of hydrocarbon gases and liquids

dc.contributor.advisorHirasaki, George J.en_US
dc.creatorZhang, Yingen_US
dc.date.accessioned2009-06-04T08:19:08Zen_US
dc.date.available2009-06-04T08:19:08Zen_US
dc.date.issued2002en_US
dc.description.abstractThe proton nuclear spin-lattice relaxation times and self-diffusion coefficients of ethane and propane were measured at elevated temperatures and pressures. It is found that pure ethane and propane depart from the linear correlations between relaxation time and viscosity/temperature and diffusivity found for pure higher alkanes and dead crude oils. The inverse relationship between the diffusion coefficient and viscosity/temperature for pure methane, pure higher alkanes, and methane-higher alkane mixtures holds for pure ethane and propane. The proton relaxation times were calculated and compared with the experimental data for ethane. The governing relaxation mechanism is shown to be the spin rotation interaction in gaseous ethane. At liquid densities, intra- and intermolecular dipole-dipole interactions and the spin rotation interaction all have significant contributions. A mixing rule was developed to estimate T 1 of gas mixtures. The estimated results by the mixing rule compared closely with experimental results for CH4-CO2 and CH 4-N2 gas mixtures. T1 and T 2 relaxation times of about 30 heavy crude oils were measured with different frequency NMR spectrometers. In addition, relaxation times of some oil samples were measured at various temperatures. Light oils have equal T 1 and T2 relaxation times. However, heavy or asphaltene crude oils have different T1 and T2 with the ratio of T1/ T2 increasing with increasing viscosity, Larmor frequency, asphaltene content and free radical content. For heavy oils, apparent T2 time constants increase and the signal amplitude decreases with increasing echo spacing. Apparent hydrogen index of heavy crude oils increases with increasing temperature. With increasing echo spacing, apparent hydrogen index of heavy oils decreases.en_US
dc.format.extent150 p.en_US
dc.format.mimetypeapplication/pdfen_US
dc.identifier.callnoTHESIS CH.E. 2002 ZHANGen_US
dc.identifier.citationZhang, Ying. "NMR relaxation and diffusion characterization of hydrocarbon gases and liquids." (2002) Diss., Rice University. <a href="https://hdl.handle.net/1911/18158">https://hdl.handle.net/1911/18158</a>.en_US
dc.identifier.urihttps://hdl.handle.net/1911/18158en_US
dc.language.isoengen_US
dc.rightsCopyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.en_US
dc.subjectChemical engineeringen_US
dc.titleNMR relaxation and diffusion characterization of hydrocarbon gases and liquidsen_US
dc.typeThesisen_US
dc.type.materialTexten_US
thesis.degree.departmentChemical Engineeringen_US
thesis.degree.disciplineEngineeringen_US
thesis.degree.grantorRice Universityen_US
thesis.degree.levelDoctoralen_US
thesis.degree.nameDoctor of Philosophyen_US
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