کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5161338 1502250 2017 28 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Mechanism of linear covariations between isotopic compositions of natural gaseous hydrocarbons
ترجمه فارسی عنوان
مکانیسم کوواریانس خطی بین ترکیبات ایزوتوپهای هیدروکربنهای گاز طبیعی
کلمات کلیدی
ایزوتوپهای کربن، ایزوتوپهای هیدروژن، گاز طبیعی، تجزیه ایزوتوپ سینتیک،
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
چکیده انگلیسی
Linear covariations between stable isotopic compositions of methane, ethane and propane have long been observed in natural gas accumulations; e.g., a plot of δ13Cpropane versus δ13Cethane of natural gas fall along a straight line. This work investigates physicochemical mechanisms behind the correlations and derives the theoretical slope value for each correlation line. Most slopes are close to the values of statistical distribution, which are 2/3 (0.67) for δ13Cpropane vs. δ13Cethane, 2 for δ13Cmethane vs. δ13Cethane, and 3/4 (0.75) for δ2Hpropane vs. δ2Hethane. When detailed kinetic isotopic effects are considered, the theoretical slope values of δ13Cpropane vs. δ13Cethane and δ2Hpropane vs. δ2Hethane change slightly to 0.68 and 0.73, respectively; the slope of δ13Cmethane vs. δ13Cethane is about 2.4. These slopes are consistent to field data of natural gas generated from kerogen before dry gas window. An exception is the slope of the δ2Hmethane vs. δ2Hethane correlation line; the deviation of field data from theoretical slope suggests that the reaction path of methane generation differs from that of ethane and propane generation; proton shift is probably involved in methane generation. The physical meanings of intra-molecular isotopic fractionation in propane and clumped isotopic fractionation in methane are discussed based on statistical and kinetic analysis.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Organic Geochemistry - Volume 113, November 2017, Pages 115-123
نویسندگان
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