BHGM Surveying of Salt Flank from Offset Well

Three cases are shown. The first case is a 2 dimensional model, simply to illustrate the BHGM response of a simple salt model and show the use of the density difference trace. The second case shows a large overhang modeled in 2.5 dimensions. The salt extends into and out of the section by 1 km each way. Sediments surround the salt on all sides. The densities of the sediments gradually grade higher with increasing depth and are shown on the left side of the section. Case 3 is similar to Case 2 with less overhang.

Case 1 - Response of salt dome when surrounding sediments are uniform density.

The BHGM density response shows a higher density than the sediment density as shown by the blue adjacent higher density salt.gamma gamma density trace due to the

The green density difference trace defined as the BHGM density minus the gamma gamma density also shows the response of the salt dome in uniform density clastic sediments.

Case 2 - A large overhang model in 2.5 dimensions.

The salt response is best seen in the density difference trace.

Case 3 - When the salt flank is less overhung the BHGM density decreases.

Again, the density difference trace is more diagnostic