Open Access

ARTICLE

Design and Performance Evaluation of a Temporary Plugging and Filtration-Reducing System Utilizing Water-Soluble Polyester Particles for Unconsolidated Sandstone

Xitang Lan^1,2,*, Guangqing Zhang¹, Wei Liu¹
1 School of Petroleum Engineering, China University of Petroleum (Beijing), Beijing, China
2 School of Petroleum Engineering CNOOC (China) Co., Ltd., Caofeidian Operation Company, Tianjin, China
* Corresponding Author: Xitang Lan. Email:
(This article belongs to the Special Issue: Ion-imprinting Polymer and Hydrogel: Fabrication, Properties and Applications)

Journal of Polymer Materials https://doi.org/10.32604/jpm.2026.086935

Received 08 June 2026; Accepted 29 July 2026; Published online 17 August 2026

Abstract

Addressing challenges such as uncontrolled fracture propagation, significant fluid loss, and rapid post-fracturing conductivity deterioration in unconsolidated sandstone reservoirs, we developed a temporary plugging fracturing system utilizing water-soluble polyester particles. A comprehensive assessment was conducted on its particle size distribution, dissolution/swelling characteristics, suspension stability, degradation behavior, as well as its efficacy in temporary plugging and fluid loss reduction. The findings revealed that the system demonstrated high operational adaptability and temporal responsiveness. The particles maintained robust suspension stability during injection, with >80 mesh particles sustaining up to a 98% suspension rate after 30 min at a 0.6 wt% concentration. This stability enabled the formation of a bridge-fill-compaction structure at pore throats and fracture entrances, thereby achieving effective temporary plugging. Following this temporary plugging, fluid loss was markedly reduced by nearly 90% (decreasing from approximately 53 mL to 5–6 mL at 30 min), effectively preventing fluid intrusion and enhancing the sealing capacity in the near-wellbore region. Over time, the particles progressively softened, fragmented, and ultimately degraded, displaying a distinct pattern of rapid initial degradation followed by gradual degradation, achieving a 91% degradation rate at 6 h and near-complete degradation (98%) within 24 h. Our research indicates that this water-soluble polyester particle temporary plugging system effectively fulfills the temporary plugging requirements of “initial temporary plugging, subsequent diversion, and eventual degradation” in unconsolidated sandstone fracturing. It achieves a harmonious integration of short-term efficient temporary plugging with high degradation and minimal damage in the later stages, offering a theoretical foundation and technical support for optimizing fracturing techniques and selecting temporary plugging materials for unconsolidated sandstone reservoirs.

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Keywords

Unconsolidated sandstone; water-soluble polyester particles; temporary fracturing; fracture redirection; degradation performance; fluid loss reduction

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