Constructing hydrocarbon reservoir analogues with rapid acquisition long-range GPR

The bounding surfaces of dunes have long been known to impart significant permeability contrasts to aeolian sequences. The resulting permeability contrasts can affect hydrocarbon flow in subsurface aeolian reservoirs, the impact of which often increases later in the life of a hydrocarbon field. In order to optimally manage petroleum reservoir development, the spatial arrangement of bounding features needs to be incorporated into subsurface models. However, adequate models cannot be obtained directly from the reservoir as no high-resolution imaging techniques exist for the inter-well area. At best, indirect inferences from an ensemble of remote data can be used to broadly constrain major features. However, many spatial parameters remain poorly constrained, particularly in 3D. GPR (Ground Penetrating Radar) has been shown to provide direct 3D imagery of near-surface deposits at a relevant scale and resolution. The resulting models may not be directly transferable to a specific subsurface scenario, but the generic spatial information can be a useful guide to reservoir engineers. Discussed herein is a case study from southern Libya employing the use of a custom long-range rapid-acquisition GPR system to develop 3D volumes over large areas.