A comprehensive approach to modeling and eliminating sanding problems during oil production.

摘要

Sand production in the petroleum industry is a phenomenon of solid particles being produced together with reservoir fluid. This is a major problem that operating oil companies have faced for many years. To date, despite several research studies, sand production remains a nightmare for petroleum engineers.; Even though many researchers have tried to predict sand production in the past, none suggested a comprehensive model that would take care of a range of failure and sand production mechanisms. Moreover, rare models predict sanding rate and volume along with the onset of sanding. This thesis presents a comprehensive numerical modeling of sand production whose criteria derive from the physics of sanding, taking the sequential nature of sand production into consideration.; The numerical model simulated two series of experiments on large-scale samples, one with vertical, and another horizontal well. The behaviour of the sample under loading, as well as the rate and volume of sanding, agreed reasonably well with the experimental results. This confirms that the criteria used for the model captured the essence of sanding.; To alleviate some of the concerns and uncertainties on the interactions between an expandable liner and the medium around it, a series of experiments were conducted using hollow cylinder synthetic sandstone samples involving both fine and coarse grained sands at varying degrees of consolidation, including totally non-cemented samples. A stiffener, which was a representative of the proposed expandable completion technique, supported the central hole of a series of samples, while another series used open hole completion.; Experiments on non-cemented highly porous sand-pack samples equipped with the stiffener indicated spontaneous sand production under single-phase flow. However, the situation was highly alleviated under a two-phase flow condition. As a result, capillarity played a determining role in holding the grains together and forming stable arches.; Finally, a straightforward analytical methodology is introduced which can predict the critical drawdown associated with the onset of sanding under either of single- or two-phase fluid flow. This formulation was applied to the experimental data of both weakly consolidated and unconsolidated sandstones. A remarkable agreement between the experimental observations and analytical predictions was concluded. (Abstract shortened by UMI.)