Methodology to Identify Presence of Resin During Post-Fracturing Flowback

Abstract

Proppant flowback can cause equipment damage and restrict hydrocarbon production, making it an expensive issue. In response to industry demands for a solution, this paper presents a methodology designed to identify and help prevent flowback issues and to exhibit high cohesive strength to increase the stability of proppant packs. Liquid resin proppant coating applied during pumping operations shows significant conductivity enhancement and fines control in hydraulic fracturing operations, as compared with traditional curable resin-coated proppant (CRCP). The concentration of resin applied follows proven industry standards. Placement technique and concentration of resin can delay the cure time if needed, which enables the proppant pack to consolidate after placement in the fractures. In addition, it enables the proppant to obtain better grain-to-grain contact in the fracture, and capillary action pulls the liquid resin coating to the contact points of the proppant grains. This process provides a highly cohesive, consolidated proppant pack. The liquid resin system was designed to be mixed with the proppant immediately before it is added to the fracturing fluid during pumping operations, to consolidate after it is carried into the fracture. Laboratory analysis demonstrates that the resin will prevent fines from flowing back, and it will remain coated on the proppant in the fracture. During the post-treatment cleanout process, a flowback sample was collected and sent to the laboratory to verify that there was no resin content present. The sample was analyzed using Fourier transform infrared (FTIR) spectroscopy, and the resulting spectra were compared to the original resin chart. No resin was present. To confirm the results, a sample of the resin used on the treatment was mixed and analyzed for comparison in FTIR spectra. This paper describes the methodology to identify the presence of resin during well cleanout and to evaluate the proppant consolidations expected. A new methodology is presented to compare the fluid returned during well cleanup and to evaluate samples in laboratory experiments.

Review and Perspectives of Coated Proppant Technology

“…Curable coated proppant refers to a layer of solid thermosetting resin on the proppant substrate (quartz sand, ceramic, glass spheres); this proppant is injected into formation fractures. Under formation temperature, in situ stress, and activator, the resins are softened and then bonded and solidified, forming a network structure. ,, Curable proppant can effectively prevent proppant flowback and inhibit the flowback of fine particles, , and the commonly used resin types are epoxy resin and phenolic resin.…”

“…Under formation temperature, in situ stress, and activator, the resins are softened and then bonded and solidified, forming a network structure. 6,58,59 Curable proppant can effectively prevent proppant flowback and inhibit the flowback of fine particles, 60,61 and the commonly used resin types are epoxy resin and phenolic resin.…”