Application of Diluted Consolidation Systems To Improve Effectiveness of Proppant Flowback Remediation—Laboratory and Field Results

Abstract

Summary Individually, coiled tubing (CT), consolidating fluids, or pressure-pulsing tools do not represent new technology. However, the combination of these technologies offers a viable solution to the proppant flowback problem after the proppant has been placed in the fracture. This paper presents the results of laboratory studies and field case histories of a remedial treatment technique through use of a low-viscosity consolidation fluid system that is placed into the propped fractures by CT or jointed pipe coupled with a pressure-pulsing tool. The treatment fluids are designed to provide consolidation (for previously placed proppant) near the wellbore to glue the proppant grains in place without damaging the permeability of the proppant pack. Laboratory flow testing indicates that the proppant pack in a fracture model under closure stress only requires low-strength bonds between proppant grains to withstand high production flow rates. The consolidation treatment transforms the loosely packed proppant in the fractures and the formation sand close to the well-bore into a cohesive, consolidated, yet highly permeable pack. Field case histories are presented and the treatment procedures, precautions and recommendations for implementing the treatment process are discussed. One major advantage of this remedial treatment method is the ability to place the treatment fluid into the propped fractures, regardless of the number of perforation intervals and the length of the perforated intervals without mechanical isolation between the intervals. The fluid-placement efficiency of this process makes remediation economically feasible, especially in wells with marginal reserves.