摘要
Using high pressure and geological condition simulation vessels, we conducted hydrous pyrolysis experiments of kerogen, solid bitumen and liquid hydrocarbons in southern China in order to study the processes of gas generation and derive geo- chemical indicators of gas genesis under approximate pressure and temperature. The results indicate that gas generation productivity of different marine material decreased in the ganic matter （solid bitumen and heavy oil）, and kerogen. order of crude oil （light oil and condensate）, dispersed soluble or- Under identical temperature-pressure regimes, pyrolysates derived from kerogen and dispersed soluble organic matter display drastically different geochemical characteristics. For example, the δ13Cc02-δ13C1 values of gaseous products from dispersed soluble organic matter are greater than 20%o, whereas those from kerogen are less than 20%~. The 813C1 values of pyrolysates from different marine hydrocarbon sources generally increase with pyrolysis temperature, but are always lower than those of the source precursors. The δ13C values of ethane and propane in the pyrolysates also increase with increasing pyrolysis temperature, eventually approaching that of their sources, at peak hydro- carbon generation. At high-over mature stages, the δ13C values of ethane and propane are often greater than those of their sources but close to those of coal gases, and thus become ineffective as gas genetic indicators. Ln（CffC3） can clearly distin- guish kerogen degradation gas from oil cracking gas and Ln（CJC2）-（δ13C1-δ13C2） can be an effective indicator for distinguishing oil cracking gas from dispersed soluble organic matter cracking gas.
Using high pressure and geological condition simulation vessels, we conducted hydrous pyrolysis experiments of kerogen, solid bitumen and liquid hydrocarbons in southern China in order to study the processes of gas generation and derive geochemical indicators of gas genesis under approximate pressure and temperature. The results indicate that gas generation productivity of different marine material decreased in the order of crude oil (light oil and condensate), dispersed soluble organic matter (solid bitumen and heavy oil), and kerogen. Under identical temperature-pressure regimes, pyrolysates derived from kerogen and dispersed soluble organic matter display drastically different geochemical characteristics. For example, the 13CCO213C1 values of gaseous products from dispersed soluble organic matter are greater than 20‰, whereas those from kerogen are less than 20‰. The 13C1 values of pyrolysates from different marine hydrocarbon sources generally increase with pyrolysis temperature, but are always lower than those of the source precursors. The 13C values of ethane and propane in the pyrolysates also increase with increasing pyrolysis temperature, eventually approaching that of their sources, at peak hydrocarbon generation. At high-over mature stages, the 13C values of ethane and propane are often greater than those of their sources but close to those of coal gases, and thus become ineffective as gas genetic indicators. Ln(C2/C3) can clearly distinguish kerogen degradation gas from oil cracking gas and Ln(C1/C2)-( 13C113C2) can be an effective indicator for distinguishing oil cracking gas from dispersed soluble organic matter cracking gas.
基金
supported by Petroleum & Chemical United Fund Project(Grant No. 40739902)
