Void and alteration zone detection on the top of a limestone unit for a gas complex

Heavy and sensitive infrastructure construction requires advanced knowledge of the underground features. The presence of limestone in a gas complex called for the recognition of possible sinkholes or alteration-prone areas.

A 10x10m grid was acquired on 1km2 and the detected anomalies were detailed through a smaller grid (5x5m)

Microgravity data correlated adequately with refraction seismology results, which led to a precise overall geological interpretation of the site.

Density anomalies allowed for the computation of bedrock depth

3D inversion of the observed gravimetric anomalies allowed the creation of bedrock depth maps. The deepening of the limestone top layers are very well correlated to refraction seismology.

High temperature have forced our engineers to work by night
Location Middle East
Instrument Scintrex CG-5
Positioning DGPS & automatic levelling
Geometry 10x10m grid
Stations 19,520
Personnel 8 people
Duration 26 days