Gravel-packing experiments with oil-swelling rubber particles

In oil and gas wells with sand-control completion, during gravel-pack installation and the production life span of the well, void spaces (holidays) might form in gravel packs. These voids provide permeable channels within the pack that allow sand to pass into the wellbore that consequently lowers the pack efficiency. Finding an innovative way to prevent the voids from forming maintains the gravelpack integrity and preserves its efficiency. This approach could save money by reducing the demand for remedial operations. This paper introduces a modified design for gravel packing with oil-swelling rubber particles. The new pack is composed of gravel- and oilswelling rubber particles capable of preventing the voids from forming and maintaining pack tightness rather than 100% gravel. Using diesel, a series of experiments was conducted on 100% oil-swelling rubber-particle packs and mixtures of gravel and rubber particles to measure their swelling capacities and permeabilities. Swelling volume and permeability measurements of the rubber particles were conducted to evaluate their capacity to fill the voids and their potential effect(s) on the hydrocarbon flow from the formation to the wellbore. The results show that gravel/rubber-particle packs have promising permeabilities and reasonable expansion potential to fill the voids. Increasing the proportion of the rubber particles in a gravel/rubber particle mixture pack results in a permeability decrease of the pack. Hence, finding an optimum proportion of rubber particles is essential to design a pack that prevents the voids from forming while retaining reasonable permeability.