A coupled CFD-DEM model for sand production in oil wells
During the oil recovery a hole is drilled, the sandstone is left unsupported next to the cavity and disloged sand grains can enter the oil recovery system. This process is called sand production and several problems may arise due to that process, as clogging up of the well or damage to the well equi...
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2016 |
| País: | España |
| Institución: | CBUC, CESCA |
| Repositorio: | TDR. Tesis Doctorales en Red |
| OAI Identifier: | oai:www.tdx.cat:10803/403981 |
| Acceso en línea: | http://hdl.handle.net/10803/403981 https://dx.doi.org/10.5821/dissertation-2117-105810 |
| Access Level: | acceso abierto |
| Palabra clave: | 55 624 |
| Sumario: | During the oil recovery a hole is drilled, the sandstone is left unsupported next to the cavity and disloged sand grains can enter the oil recovery system. This process is called sand production and several problems may arise due to that process, as clogging up of the well or damage to the well equipment. The study of sand production process is of paramout importance for safe and economical hydrocarbon production. The majority of numerical models to predict sand production that have been used to date are continuum-based. However, a continuum approach cannot easily capture important features of the sanding problem, such as erosion, and it requires the formulation recognized as a difficult task because of the large number of interactions and non-lineaities intrinsic to the problem. On the other hand, discrete-element based approaches allow a simpler formulation of the problem and a better understanding of some of its features. Discrete Element Methods (DEM) describe more naturally the disaggregation and erosion of sand particles and the fluid-solid interaction. In this research rock behavior has been epresented in DEM using the parallel-bond model (PBM) because it mimics the effect of cement between particles. The study has involved the calibration of the DEM rock model agains real data. Moreover, limitations of the DEM model have been explored and sensitivity analyses examining the effects of the local damping have been performed. The main aim of this research is to improve the understanding of sand production based on a Computational Fluid Dynamics (CFD) -DEM coupling model. CFD-DEM is frequently used for process and chemical engineering problems (Zhu et al., 2007). To simulate the interaction of the particles with the fluid, the solid DEM model is coupled with a fluid model (CFD). A validation of the CFD-DEM model has been carried out in this thesis by performing single particle simulations and analyses of ermeability tests. Simulations of sand production using a omogeneous sandstone analogue and, finally, the simulation of sand production under realistic conditions are presented. |
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