Combining GPR and Terrestrial LiDAR to Produce 3D Virtual Outcrop Models

Terrestrial LiDAR provides high-resolution outcrop data in 2.5D to provide quantitative reservoir analogues through the interpretation of structural geometries and sedimentological architectures within the outcrop at sub-centimeter scale. The resulting interpretation is used to provide a qualitative check on the validity of reservoir models. However, without subsurface information geological surfaces and features are usually extrapolated into the subsurface using probabilistic or deterministic approaches. As LiDAR is non-penetrative outcrop models cannot be considered truly 3D and without a subsurface constraint, inferred geometries generate significant uncertainties within a model. This may be overcome through geophysical imaging of the subsurface, and use of ground penetrating radar for instance. Integration of GPR datasets with terrestrial LiDAR allows one to improve the validity of subsurface interpretations. We present studies that have benefitted from the combined use of GPR and LiDAR in the characterization of the 3D geometries and propose further studies that would be improved through the use of a truly 3D outcrop model. GPR offers the opportunity of sub-seismic scale detail of facies distributions, architectures and geometry and when integrated with high precision LiDAR, provides a well-constrained method of building reservoir models.