摘要
Condensates and light oils are generally characterized by high maturity, low concentration of sterane and terpane biomarkers and low content of non-hydrocarbon fraction. As a result, some commonly-used sterane, terpane and carbazole migration parameters in conventional oil reservoirs may have a certain limitation in condensate and light oil reservoirs for their poor signal-noise ratios in the gas chromatography-mass spectrometry （GC-MS）. Naphthalene, phenanthrene and their methylated substituents, however, are present in significant concentrations in condensates and light oils. Taking the Fushan depression （in the Beibuwan Basin, Northern South China Sea） as an example, this paper attempts for the first time to use polycyclic aromatic hydrocarbon （PAH）-related parameters to trace migration directions and filling pathways for condensate and light oil reservoirs. The result shows that TMNr （i.e. 1, 3, 7-TMN/（1, 3, 7-TMN ＋ 1, 2, 5-TMN）, TMN： trimethylnaphthalene））, MPI-1 （i.e. 1.5×（2-MP ＋ 3-MP）/（P ＋ 1-MP ＋ 9-MP）, P： phenanthrene MP： methyiphenanthrene）, MN/DMN （∑methylnaphthalene/∑dimethylnaphthalene, %） and MN/TMN （∑nethylnaphthalene/∑trimethylna- phthalene, %） can be used to trace the filling pathways of condensate and light oil reservoirs. These parameters, together with geological consideration and other bulk oil properties （e.g. the gas to oil ratio and density）, suggest that the condensates and light oils in the Huachang oil and gas field are mainly sourced from the Bailian sag that is located to the northeast of the Huachang uplift in the Fushan depression.
Condensates and light oils are generally characterized by high maturity, low concentration of sterane and terpane biomarkers and low content of non-hydrocarbon fraction. As a result, some commonly-used sterane, terpane and carbazole migration parameters in conventional oil reservoirs may have a certain limitation in condensate and light oil reservoirs for their poor signal-noise ratios in the gas chromatography-mass spectrometry （GC-MS）. Naphthalene, phenanthrene and their methylated substituents, however, are present in significant concentrations in condensates and light oils. Taking the Fushan depression （in the Beibuwan Basin, Northern South China Sea） as an example, this paper attempts for the first time to use polycyclic aromatic hydrocarbon （PAH）-related parameters to trace migration directions and filling pathways for condensate and light oil reservoirs. The result shows that TMNr （i.e. 1, 3, 7-TMN/（1, 3, 7-TMN ＋ 1, 2, 5-TMN）, TMN： trimethylnaphthalene））, MPI-1 （i.e. 1.5×（2-MP ＋ 3-MP）/（P ＋ 1-MP ＋ 9-MP）, P： phenanthrene MP： methyiphenanthrene）, MN/DMN （∑methylnaphthalene/∑dimethylnaphthalene, %） and MN/TMN （∑nethylnaphthalene/∑trimethylna- phthalene, %） can be used to trace the filling pathways of condensate and light oil reservoirs. These parameters, together with geological consideration and other bulk oil properties （e.g. the gas to oil ratio and density）, suggest that the condensates and light oils in the Huachang oil and gas field are mainly sourced from the Bailian sag that is located to the northeast of the Huachang uplift in the Fushan depression.
基金
supported by the Natural Science Foundation of China(Grant No.40972089),CNPC Innovation Fund(Grant No.07E1001)
the State Key Laboratory of the Petroleum Resources and Prospecting(Grant No.PRPDX2008-01)
