WITSML Element Types Sequence number of section, 1,2,3. Section scope: Line or Arc. Length of straight line section or radius of arc for continuous curve section. Direction of straight line section or radius of arc for continuous curve section. Height of target above center point at the start of the section. In the case of an arc, the thickness above should vary linearly with the arc length. Depth of target below center point at the start of the section. In the case of an arc, the thickness below should vary linearly with the arc length. The 2D coordinates of the item at the start of the section. This is redundant information and can be computed by starting at the section origin and applying the sequence of angleArcs and lenRadius. Unique identifier for the section.