Abstract

In recent years, the Pematang Formation in the Central Sumatra Basin has been extensively investigated. Previous structural interpretations were based primarily on seismic data. However, in some areas the interpretation is still uncertain mainly due to poor data continuity in deeper horizons. To give better definition of structure in deeper horizons, gravity analysis combined with seismic and well data is interpreted by a so-called "Stripping" technique. The purpose is to subtract the calculated gravity effects of the Sihapas Group from the observed Bouguer gravity in order to produce a residual anomaly of the underlying Pematang Formation. This anomaly is then used as a basis to define a geometrical shape of basement.

The primary interest of this paper is to describe the practical procedure of stripping and its application.

Three examples taken from part of the Central Sumatra Basin are given to show the application of stripping.