Interval velocities in the Danish Central Trough

摘要

Interval velocity is calculated for a number of lithostratigraphic units in the Danish Central Trough based on two-way times and depths encountered in 76 exploration and appraisal wells released by January 1st 1993. For most of these units velocity increases with depth and linear velocity parameters are estimated for these units. The correction needed to calibrate the linear velocity model to well data is the change in the constant term in the model for a given layer, that will lead to the measured thickness of that layer in a given well. This calibration constant, the velocity anomaly, is calculated in each well for each layer with given linear velocity parameters. As the compaction effect of the late Cenozoic subsidence is limited, linear velocity parameters and velocity anomalies are calculated relative to depth below top Middle Miocene. For each of the units optimal constant velocity for depth conversion is given, as well as the range of velocity, depth to top and thickness of the unit for wells drilled away from diapirs and for wells drilled on or near diapirs. The data are presented in tables and as maps and cross plots.