Li Shuanggui, Qi Biao, Zhang Qitao, Yang Jingbin
Key Laboratory of Enhanced Oil Recovery in Carbonate Fractured-Vuggy Reservoirs, SINOPEC, Urumqi 830011, China.
SINOPEC Northwest Company of China Petroleum and Chemical Corporation, Urumqi 830011, China.
Gels. 2024 Sep 20;10(9):599. doi: 10.3390/gels10090599.
Thermosetting resins have good temperature resistance and high strength and have been widely used as plugging agents in oil fields. However, the current resin materials have high costs, and unmodified thermosetting resins are brittle or have deteriorated properties such as flame retardancy after curing to form a crosslinked network structure. In this study, the resin was modified via physical blending. The curing strength and temperature resistance were used as the main indicators. The resin matrix, curing agent, rheology modifier, and filling materials were modified and formulated optimally to form a high-strength resin gel plugging system. The resin gel system exhibited good fluidity and pumpability. When the shear rate was 200 s at 25 °C, the initial viscosity was 300-400 mPa·s. The viscosity gradually decreased with increasing shear rate, and the apparent viscosity had good long-term stability at room temperature. A contamination test of different types of drilling fluids on the resin gel system showed that this system had good anti-contamination capability and could maintain a high curing strength even after being contaminated. At the same time, the system exhibited good plugging capability. A wedge-shaped fracture with an inlet size of 7 mm and an outlet size of 5 mm was plugged at 12.84 MPa for 10 min without leakage. A sand-filling pipe (with a diameter of 3.8 cm and pipe length of 30 cm) connected to the pipeline with a 6 mm outlet was subjected to a constant pressure of 11.29 MPa and plugged for 8 min before breaking through. Therefore, it exhibited good capability for plugging fissures and cavities. The resin gel leakage-plugging system has significant potential to realize effective plugging of the deep large-fracture leakage layer.
热固性树脂具有良好的耐高温性和高强度，已在油田中广泛用作堵漏剂。然而，目前的树脂材料成本高昂，未改性的热固性树脂在固化形成交联网络结构后脆性大或具有诸如阻燃性等性能劣化的问题。在本研究中，通过物理共混对树脂进行改性。以固化强度和耐高温性作为主要指标。对树脂基体、固化剂、流变改性剂和填充材料进行改性并优化配方，形成一种高强度树脂凝胶堵漏体系。该树脂凝胶体系表现出良好的流动性和可泵性。在25℃下，当剪切速率为200 s⁻¹时，初始粘度为300 - 400 mPa·s。粘度随剪切速率的增加而逐渐降低，且表观粘度在室温下具有良好的长期稳定性。对不同类型钻井液对树脂凝胶体系的污染试验表明，该体系具有良好的抗污染能力，即使在被污染后仍能保持较高的固化强度。同时，该体系表现出良好的堵漏能力。在12.84 MPa下对入口尺寸为7 mm、出口尺寸为5 mm的楔形裂缝封堵10 min无渗漏。将一根与出口为6 mm的管道相连的填砂管（直径3.8 cm，管长30 cm）施加11.29 MPa的恒压并封堵8 min后才被突破。因此，它表现出良好的封堵裂缝和孔洞的能力。该树脂凝胶堵漏体系在实现对深部大裂缝大裂缝性漏失层的有效封堵方面具有巨大潜力。
