# Preparation and Applicability Evaluation of High-Temperature-Resistant, Breakable Resin–Gel Plugging Agent

## TL;DR

A high-temperature-resistant plugging agent was developed to prevent gas channeling in oil and gas wells, showing strong performance in extreme conditions.

## Contribution

A novel resin–gel plugging system with controlled gel-breaking and high thermal stability is introduced for high-temperature reservoir applications.

## Key findings

- The plugging system withstood 150 °C with a G′ ≥ 125 Pa and compressive strength > 18 MPa.
- It showed strong contamination resistance with <9.7% viscosity reduction and >87% storage modulus retention after drilling fluid mixing.
- The system achieved ≥99.7% gel-breaking rate within 21 days and >92% plugging efficiency for fractures up to 2 mm wide.

## Abstract

This study addresses the challenge of high-temperature gas channeling in injection–production wells of karst-fractured reservoirs by developing a high-temperature-resistant resin–gel plugging system capable of withstanding up to 150 °C. The system employs an AMPS/NVP copolymer (molar ratio 3:1) as the polymer matrix, reinforced with phenolic resin to enhance the crosslinked network. Additionally, a polyamide microcapsule was utilized to encapsulate the gel breaker, enabling controlled release. The optimized formulation consists of 0.5% NEP, 0.5% DEP, 0.6% HMTA, 0.3% catechol, and 25% resin curing agent. Experimental results demonstrate that the system exhibits excellent stability at 150 °C, with a G′ ≥ 125 Pa and compressive strength > 18 MPa. It also displays strong contamination resistance, showing a viscosity reduction of <9.7% and a storage modulus retention rate > 87% after mixing with drilling fluid. Furthermore, the gel-breaking performance is controllable, achieving a gel-breaking rate ≥ 99.7% within 21 days. Under high-temperature and high-pressure conditions (150 °C), the system demonstrates a plugging efficiency > 92% for simulated fractures with widths ranging from 0.1 to 2 mm. This technology effectively suppresses gas channeling in complex high-temperature formations, making it suitable for gas injection wells in karst-fractured reservoirs. It also holds promise for extension to shale gas wells and geothermal reservoir sealing applications.