Summary Sand production is a critical challenge in weakly-consolidated sandstone reservoirs, especially in mature wells where complex sand-induced voids develop after repeated production and sand-control operations. Conventional gravel-packing design often relies on empirical parameter selection, limiting the predictability and optimization of packing effectiveness. This research presents a systematic experimental investigation of gravel packing under different sand-production morphology. A total of 15 experiments were conducted, revealing distinct packing behaviors across large-hole, cellular-hole, and wormhole morphologies, and identified three packing modes: undersaturated packing (USP), equilibrium saturated packing (ESP), and oversaturated packing (OSP). The results show that in terms of comprehensive sand retention and flow capacity, the ESP mode is the most ideal, resulting in the highest final permeability ratio of 0.256. It effectively prevents sand migration while maintaining favorable flow channels. Microscale analysis further showed that excessive proppant in minor voids can lead to oversaturated zones with mixed sand/gravel interfaces, reducing overall packing efficiency. These results provide quantitative insights into the mechanisms controlling gravel transport and deposition, establishing practical guidelines for optimizing squeeze-packing design. By linking void morphology, packing mode, and performance, the study offers valuable guidance to improve the reliability and effectiveness of sand-control operations in weakly consolidated sandstone reservoirs.
Wang et al. (Wed,) studied this question.