Coiled Tubing Deployed Resin Treatment Remediates Proppant and Formation Sand Flowback in High-Temperature Wells: A Field Study in South Texas

摘要

Flowback of proppant and formation sand can often become problematic for operators because the solids cause equipment damage, costly cleanup treatments, and potential loss of production. These flowback problems are often compounded in severity in wells with high temperature and high pressure. Operators seek reliable solutions to (1) eliminate the need for frequent remedial cleanouts and surface equipment replacement and (2) to maximize revenues by increasing and maintaining production rates. This paper presents a field case study that discusses the remedial treatments and knowledge gained from more than 30 wells in south Texas where proppant and formation-sand flowback problems have been encountered by the operator. It also discusses the development and treatment processes using low-viscosity consolidating agents to be applied in the treatments. Examples presented illustrate how the problems were successfully overcome in these high-temperature wells. Field results indicate that more than 90% of these consolidation treatments have effectively stopped the flowback of proppant and formation sand while allowing the production rates of the wells to be increased. These treatments have drastically decreased the number of workovers compared to the period before their treatments, or compared to the offset wells in the same field where consolidation treatments were not performed. This study demonstrated that an effective coating of a curable resin on the proppant and formation sand close to the wellbore is necessary to help maximize the consolidation bonding between grains within the pack while minimizing any reduction of its permeability. This new remedial-treatment process greatly enhances the effectiveness of fluid placement into the propped fractures, regardless of the number of perforation intervals and their lengths and without mechanical isolation between the intervals. The simplicity of treatment helps make remediation economically feasible, especially in wells with marginal reserves.