Inverse-volume pore pressure projection technique for the coupling of reservoir flow and geomechanics simulators

摘要

Coupling geomechanical reservoir models with fluid flow models improves accuracy whenrnsimulating phenomena relevant to production forecast, drilling and well integrity, and environmental impactrn(e.g. fault reactivation). A geomechanical model provides to a hydrodynamical model updated values of porernvolume and permeability, and a hydrodynamical model in turn provides to a geomechanical model updates tornthe pore pressure, which then alters effective stress. The main challenge in coupling is the exchange of data.rnThis work presents three different pore pressure projection schemes used for data exchange, that are based onrnweighted averages (inverse distance, volume, and by inverse of the volume). To validate the three methods, thernpressure projected was compared with a hydrostatic pressure distribution while accounting for changes in thernsize of the surrounding cells of the hydrodynamical model. The weighting by the inverse of the volume showsrnthe better agreement with hydrostatic pore pressure distribution of the three techniques presented. As a furtherrndemonstration, the three methods were compared within a small reservoir model with varying cell sizes, and therninverse volume method performs favorably. Finally an extension to the inverse volume method was developed,rnin which permeability is included in the weighting factors. Its effect is demonstrated in a benchmark systemrnincluding both a reservoir and a nonpay region.