Behavior of Chain Alkane Molecular Components in PVT Fractionation Experiment

SU Ai-guo; ZHANG Shui-chang; HAN De-xing; WANG Yan-bing

An understanding of the ratio variation of chain alkane molecular components of oils in petroleum reservoir is important for successful study on reservoir formation and petroleum geochemistry. Pressure-falling and gas-washing fractionations, which are two main process of reservoir formation , are simulated by PVT experiments. Measuring the molecular composition of chain alkane of the products formed in the different experiment stages, the analytical results show that: ①A great deal of condensates, which is not from thermal generation, most come from gas-washing fractionations; ② Pressure-drop and gas-washing fractionations are of similar variation in some alkane ratios of the oil, such as the decrease of ratios of Pr/Ph,(Pr+Ph)/(nC₁₉+nC 20) and nC ₁₀/(nC₁₆+nC₂₅); ③The difference between pressure-falling and gas-washing fractionations shows that some alkane parameters of the condensates from the two different processes change in diverse direction; ④Some routine geochemical parameters can be also affected by pressure-falling and gas-washing fractionations.

Behavior of Chain Alkane Molecular Components in PVT Fractionation Experiment

1. China University of Mining and Technology, Beijing 100083;

2. Research Institute of Petroleum Exploration and Development, CNPC Beijing 100083

Received Date: 2003-05-20

Rev Recd Date: 2004-02-10

Publish Date: 2004-06-10

Key words:

Abstract: An understanding of the ratio variation of chain alkane molecular components of oils in petroleum reservoir is important for successful study on reservoir formation and petroleum geochemistry. Pressure-falling and gas-washing fractionations, which are two main process of reservoir formation , are simulated by PVT experiments. Measuring the molecular composition of chain alkane of the products formed in the different experiment stages, the analytical results show that: ①A great deal of condensates, which is not from thermal generation, most come from gas-washing fractionations; ② Pressure-drop and gas-washing fractionations are of similar variation in some alkane ratios of the oil, such as the decrease of ratios of Pr/Ph,(Pr+Ph)/(nC₁₉+nC 20) and nC ₁₀/(nC₁₆+nC₂₅); ③The difference between pressure-falling and gas-washing fractionations shows that some alkane parameters of the condensates from the two different processes change in diverse direction; ④Some routine geochemical parameters can be also affected by pressure-falling and gas-washing fractionations.

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Reference (13)

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Behavior of Chain Alkane Molecular Components in PVT Fractionation Experiment

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