| Abstrakt: |
This paper describes the application of Discrete Element Methods(DEM), [5, 14, 11, 12], to model the mechanics of sand production in oil recovery processes. Sand production occurs when a weak sandstone matrix disintegrates due to changes in fluid pressure gradient and/or effective stress. The principal goal of this work is to investigate possible mechanisms contributing to sand production that occur at the microscopic scale. Experimental results indicate that sanding processes are localized in nature, episodic, hysteretic, and depend on the fluid saturation and mobility in the porous matrix, [8, 3]. It is the coupled motion of the fluid and solid phases that we seek to model in this work. The sandstone matrix is modeled as an assemblage of bonded particles, providing a mechanism to simulate the tensile strength in the bulk material, attributable to cementation or capillary forces. A flow model based on Darcy's Law is incorporated in an existing DEM system to investigate the effect of flow rate on the collapse of the matrix. |
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