Abstract: Huanghua depression is in Bohai Bay basin，where tectonic activity is intene and frequent，and igneous rock developed
well in this area，especially diabase. The reservoir of diabase alteration zone which is generated by diabase baking
provides a direction to find new types of oil and gas reservoirs. This paper takes well logging data of drilling diabase alteration
zone in R district of Dagang Oilfield as examples，and summarizes the characteristics of log response and wave impedance，
then predicts the distribution and thickness of diabase alteration zone by combining the impedance inversion data volume with
multi-attribute inversion natural gamma data volume. As a result，diabase thickness is in good agreement with the wells statistics
and this provides an important reference for further exploration of diabase alteration zone reservoir in the region.

Key words: alteration zone, impedance inversion, multi-attribute inversion, seismic attribute, natural gamma