PVT分馏实验中链状烷烃分子的行为

通过PVT分馏实验模拟油藏形成过程中的温压和气洗分馏作用,测量不同实验不同分馏阶段产物的烷烃分子组成,其结果表明:①大量的非热成因凝析油应主要与气洗作用有关;②降压和气洗分馏作用的相似性主要表现为原生油中Pr/Ph、(Pr+Ph)/(nC₁₉+nC₂₀)和nC₁₀/(nC16+nC₂₅)等比值的降低;③降压和气洗分馏作用差异性表现为凝析油链烷烃参数上相反的变化规律;④温压和气洗作用可以引起某些成因或类型参数(如Pr/Ph)的明显变化。这一认识将有助于油气成藏过程的确定和常规地化指标的科学应用。

Behavior of Chain Alkane Molecular Components in PVT Fractionation Experiment

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.