问答题 翻译：Conditions of viscous flow mean that the rate of flow will be sufficiently low to be directly proportinal to the potential gradient.

问答题 翻译：The data for subsurface maps are obtained from a number of sources.

问答题 翻译：It has been suggested that an effective oil source rock generates 10-40 bbl of oil per acre ft (0.0013-0.0052cc/cc) for each one per cent of organic carbon. This is approximately 500-2000 ppm by weight。