| dc.description.abstract | A numerical model is developed for predicting perforation cavity evolution during the early stage of sand production. The objective of this thesis is to propose a new sand-rate-prediction model based on coupling fluid and geomechanics models with optimized parameters determined by sand rate laboratory experiments. Several parameters are determined from the sand production experiments collaborated with the SINTEF laboratory, Norway.
Sand rate experiments are conducted using semi-cylindrical cores with 20 cm in diameter and 20 cm in length with a 2-cm-diameter hole. The confining loads are applied from three directions on the core. Fourteen tri-axial experiments were performed using Castlegate sandstone. With different stress ratio (kr =σ_r/σ_R ,kz=σ_R/σ_Z ,σ_r ∶ minimal horizontal stress, σ_R ∶ maximum horizontal stress, σ_z vertical stress) and the same flow rate, the coefficients of the equation of the sand particle release rate were matched.
By running simulation program for all the SINTEF experiments with the optimized parameters, it is observed that the coefficients are dispersed. Using the average of sand-release rate coefficients determined from the SINTEF experiments, the simulation model is applied to the perforation evolution under various field conditions. The field simulation results show sand production is influenced by many factors such as well inclination, anisotropic permeability and perforation phasing. | en |
