Layer cake depth conversion, Part I

In areas of uniform lithology which have not undergone tectonic inversion or severe structural deformation, depth conversion can often be performed according to some simple mathematical function (e.g., average velocity as a linear function of depth). In areas where there are dramatic changes of velocity, such as thick carbonate or evaporite units alternating with thick clastic units (as those found in the southern North Sea basin), then simple functions cannot adequately cope with the inherent velocity inversions and are inadequate for depth conversion.