Numerical Investigation for Fracture Saturation in Multilayer Sedimentary Rock in Unsymmetrical Case

Abstract:

Opening mode fractures in multilayer sedimentary rock often are periodically distributed with fracture spacing scaled to the thickness of the fractured layer. In this paper, based on Rock Failure Process Analysis Code RFPA2D, a three layer model with a central layer and with the different thickness top and bottom layer, progressive formation in multilayer sedimentary rock at fracture saturation in unsymmetrical case is simulated. We investigate the change of the critical fracture spacing to layer thickness ratio as a function of the thickness of the top layer where the bottom layers is much thicker (5 times) than the fractured layer called the unsymmetrical case, in this unsymmetrical case, fracture saturation is simulated. By numerical simulation of RFPA2D, the critical spacing to layer thickness ratio decreases and tend to the same constant value as the thickness of the top layer increases. Numerical simulation shown that for the unsymmetrical case, if the adjacent layers are thicker than 1.5 times the thickness of the fractured layer, the multilayer sedimentary rock can be treated approximately as a system with infinitely thick top and bottom layers at fracture saturation.That should be useful in the design of engineering systems and in the prediction of fracture spacing in hydrocarbon reservoirs and groundwater aquifers.

• Periodical: Advanced Materials Research (Volumes 690-693)
• Pages: 3050-3053
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.690-693.3050
• Online since: May 2013
• Authors: Feng Shan Han, Li Song
• Keywords: Fracture Saturation, Multilayer Materials, Numerical Simulation, Sedimentary Rock, Unsymmetrical Case

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