The Agip NSD-1 well at Tananger

Abstract

Geological description of well logs, cuttings and surface samples in the Tananger-Sandnes area was carried out in order to gain a wider understanding of the Caledonian nappe sequences. The upper part of the Jæren Nappe Complex comprises gneisses, amphibolite, marble and calc-silicate gneiss. This may be equivalent to the mica gneiss and minor calcite marbles seen in the NSD-1 well. A log break at around 550 m may correlate with the contact between the upper and middle parts of the nappe complex. The fault zone separating the middle and lower parts is most probably located in the interval 900-950 m, but is difficult to detect in log interpretations. Below this level the dominant rock-types are more granitic compared with these above. The NSD-1 well does not penetrate the contact between the Jæren Nappe Complex and the basement.