ABSTRACT: Salt Dynamics and Sediment Maturity

R. O. Thomsen, I. Lerche

The use of sophisticated fluid-flow/compaction models in an integrated basin analysis is complicated by the presence of salt in various shapes in the subsurface. Significant errors can be induced in the predictions of maturity and hydrocarbon generation for the basin as a whole when extrapolating the temperature data and maturity markers from salt structures into the areas away from the salt. We demonstrate the importance of determining the thermal anomaly caused by the presence of salt and describe the heat flow as a result of a regional heat flow pattern and an anomalous local heat flow focused by the presence of salt. The technique is applied in the Sogne basin, located in the northeast part of the Danish Central graben. Extrapolation of temperature data and assessed h at flow from the Lulu 1 well induces a significant error when the hydrocarbon generation is modelled away from the Lulu structure. By using a regional heat-flow pattern for the Sogne basin, the modeled maturity and hydrocarbon generation become more reliable and accurate.

AAPG Search and Discovery Article #91003©1990 AAPG Annual Convention, San Francisco, California, June 3-6, 1990