WITSML - Reference Point Component Schema. Human recognizable context for the point. The kind of point. For example, 'well reference point', 'platform reference point', 'sea surface', 'sea bottom'. The gravity based elevation coordinate of this point as measured from a datum. Positive moving upward from the elevation datum. The measured depth coordinate of this reference point. Positive moving toward the bottomhole from the measured depth datum. This should be given when the reference is "downhole", such as an ocean bottom template, or when the reference point is also used as a vertical well datum. The measured depth value can be used to determine if the reference point and a vertical well datum are at the same point. Two dimensional coordinates that locate the point. A textual description of the point. Unique identifier for the point.