A modified design for gravel packing with expandable rubber beads

In oil and gas wells with sand control completion, during gravel pack installation and production life of the well, void spots - known as hotspots - may form in gravel packs. Hotspots provide permeable channels within the pack that allow sand to pass into the wellbore and consequently loosen the pack. Finding an innovative way to prevent hotspots from forming maintains the gravel pack integrity and preserves its efficiency. Indeed, this approach would save money by reducing the demand for remedial operations. This paper introduces, a modified design for gravel packing with expandable rubber beads. The new pack is composed of gravel and expandable rubber beads rather than 100% gravel and is capable of avoiding the hotspots and maintaining pack tightness. A series of experiments were conducted, with diesel, on 100% expandable rubber bead packs and mixtures of gravel and bead to measure their swelling capacity and permeability. The swelling volume was evaluated to assess the beads capacity to fill the hotspots and permeability was measured to assess their potential to create flow barrier. The tests show promising permeabilities for gravel/ rubber bead packs and reasonable expansion potential to fill the hotspots. Increasing the proportion of the beads in gravel/rubber bead mixture pack, results in very low permeability. Hence, finding an optimum proportion of rubber beads is essential to designing a pack that will take advantage of their swelling capacity to avoid hotspots while retaining reasonable permeability toward the flow.