论文部分内容阅读
许多石油地质和地球化学工作者似乎赞成,油气运移可能不是单一的机制,而是在不同时间,不同埋藏阶段中不同的机制在起作用。在地质条件下,烃类靠扩散作质量转移的速度估价,曾有很多争论。据史密斯(Smith,1971)等人的意见,甲烷扩散是非常缓慢的过程。据他们计算,甲烷通过1,740米厚,平均孔隙度为15。7%的碎屑沉积物需要14,000万年。但是据潘迪(Panday)等1974年的计算,在50年内从某一储层的聚集中通过122米的灰岩盖层逸散了7,870标准米~3的氦气。本文的目的是定量估价(根据新的扩散系数和数学模式)扩散在油气初次运移中的作用。
Many petroleum geologists and geochemists seem to agree that oil and gas migration may not be a single mechanism but that different mechanisms at different times and in different burial stages are at work. Under geological conditions, there have been many controversies over how quickly hydrocarbons can be valued for mass transfer. According to Smith (1971) and others, methane diffusion is a very slow process. According to their calculations, it takes 140 million years for methane to pass through 1,740-meter-thick clastic sediments with an average porosity of 15.7%. However, Panday et al. (1974) calculated that 7,870 nm3 of helium gas was evacuated from the accumulation of a reservoir within 122 years through a 122-m limestone cap over 50 years. The purpose of this paper is to quantitatively evaluate (based on new diffusion coefficients and mathematical models) the role of diffusion in the primary migration of hydrocarbons.