Proppant Pack Stability Enhanced by the Combination of New Fiber Technology and Resin- Coated Proppants

Abstract

Hydraulic fracturing has been used for many years as an effective stimulation method in high- and medium-permeability formations where, in contrast to low-permeability formations, the objective is to create a highly conductive proppant pack that bypasses the formation damage. Proppant flowback can affect the stability of the proppant pack and lose the required conductivity in the near-wellbore area. The present work shows how the proppant flowback was significantly decreased by the combination of new fiber technology and resin-coated proppant (RCP) without affecting the productivity index. Many methods to prevent proppant flowback have been used successfully, but when challenging production conditions are encountered in high- and medium-permeability hydraulically fractured wells, these methods have been proven ineffective. Low closure stress, high flow rates, high pressure drawdown, multiphase flow, high-viscosity fluids, and stress cycling are some of the conditions that favor proppant flowback. The combination of new fiber technology with RCP has been demonstrated to be effective in controlling the return of proppant in wells that were hydraulically fractured by an operator in Ecuador. The new fibers increase the frictional forces between the chemically resin-bonded proppant pack grains by creating a random network of fibers around the proppant grains. The proppant pack stability is increased by the combination of the two mechanisms. The fibers provide additional particle-to-particle mechanical bonding due to friction increase at the contact point, and the RCP provides chemical bonding. Initially, wells were treated only with RCP but as more challenging conditions were encountered, RCP by itself became ineffective; then, the new proppant flowback fibers were introduced. The new fibers provided better adhesion between the fibers and the proppant, which significantly increased the proppant pack stability and created a long-lasting conductive proppant pack. The combination of the two methods was implemented starting in 2022 in 15 wells in the Oriente Basin in Ecuador. These wells have reported no proppant flowback under harsh production conditions like stress cycling and high production rates in intervals with few perforations. The incorporation of a more stable proppant pack has allowed the operator to flow back the wells at higher initial flowback rates. This has resulted in a cleaner fracture proppant pack and higher post-fracture production rates. The combination of RCP and new proppant flowback fibers provided maximum flowback control without affecting the productivity index. The addition of the fibers provides better proppant pack consolidation, and this starts as soon as the fracture closes without requiring waiting for the resin bonding activation by temperature.