深层裂缝型油藏有机-无机纳米杂化凝胶控水增油效果

Water Control and Oil Increasing Effect of Organic-inorganic Nano-hybrid Gel in Deep Fractured Reservoirs

钱 真 李晶辉 吕东方 张 雯 甄恩龙 瞿博超 李宗睿 赵 光

QIAN Zhen LI Jinghui LYU Dongfang ZHANG Wen ZHEN Enlong QU Bochao LI Zongrui ZHAO Guang

随着深层裂缝型油藏的开发，水窜现象日益显现，导致地层能量的浪费和采收率的降低。极端非均质性是具有复杂缝网的裂缝型油藏水窜的主要原因，封堵水窜通道迫在眉睫，而堵剂是其核心所在。深层裂缝型油藏具有高温（≥110 ℃）、高盐（≥20×104 mg/L）的特点，普通凝胶难以稳定，因此通过重氮化反应和氧化反应，利用3-氨基，4-羟基苯磺酸在纳米二氧化硅（SiO2）中引入羟基和酚羟基结构，合成改性纳米 SiO2交联剂，再将其与非离子型聚合物、乌洛托品、对苯二酚反应，制得纳米杂化凝胶。以成胶效果和脱水率为指标，对纳米杂化凝胶的配方进行了优选，评价了其稳定性、黏弹性和封堵性，并依据西北油田典型裂缝型油藏地质模型建立耐温耐压可视化缝网模型，分析剩余油分布规律，确定多轮次堵水效果。结果表明，配方为0.8%非离子型聚合物+0.2%纳米SiO2+0.4%乌洛托品+0.4%对苯二酚的纳米杂化凝胶可在≤140 ℃范围内保持稳定 60 d，脱水率＜10%。纳米SiO2显著提高了杂化凝胶的黏弹性。纳米杂化凝胶对不同尺度（1～10 mm）的单裂缝均具有良好的封堵效果。在140 ℃、回压2 MPa、矿化度22×104 mg/L 的条件下，通过纳米杂化凝胶多轮次封堵实验可提高缝网模型采收率15.9百分点。纳米杂化凝胶具备优异的耐温抗盐性、黏弹性和长期稳定性，在深层裂缝型油藏中具有良好的封堵性能和提高采收率潜力。

As the development of deep fractured reservoirs，water channeling has become increasingly prominent，leading to the wastage of formation energy and a decrease in oil recovery efficiency. The primary cause of water channeling in these complex fracture networks is extreme heterogeneity. Urgent measures are required to plug these water breakthrough channels，with plugging agents playing a central role in addressing this challenge. Deep fractured reservoirs are characterized by high temperatures（≥ 110 ℃）and high salinity（≥20×104 mg/L）. Under these conditions，conventional gels struggle to maintain stability. To overcome these challenges，modified nano-silica was synthesized by introducing hydroxyl and phenolic hydroxyl groups into nano-silica through diazotization and oxidation reactions using 3-amino-4-hydroxybenzenesulfonic acid. This modified nano-silica was then reacted with nonionic polymer，hexamethylenetetramine（HMTA），and hydroquinone to produce a nano-hybrid gel. The formula of nano-hybrid gel was optimized based on gelation performance and dehydration rate. The stability，viscoelasticity and blocking capability of nano-hybrid gel were evaluated. A temperature and pressure-resistant visualized fracture network model was established according to the geological model of typical deep fractured reservoirs in Northwest oilfield. The residual oil distribution patterns were analyzed，and then the multi-round blocking effectiveness was determined. The results showed that the nano-hybrid gel with formula of 0.8% nonionic polymer，0.2% modified nano-silica，0.4% HMTA and 0.4% hydroquinone could remain stable for up to 60 days at temperatures ≤140 ℃ with a dehydration rate <10% . Modified nano-silica significantly enhanced the viscoelastic properties of nano-hybrid gel. The nano-hybrid gel exhibited excellent blocking effects on single fractures with various scales （1—10 mm）. Under the condition of 140 ℃，2 MPa backpressure and 22 × 104 mg/L salinity，multi-round blocking experiments with nano-hybrid gel increased the recovery efficiency of fracture network model by 15.9 percentage points. The nano-hybrid gel demonstrated superior thermal and salt resistance，viscoelasticity and long-term stability，which made it well-suited for effective plugging and enhanced oil recovery in deep fractured reservoirs.

10.19346/j.cnki.1000-4092.2025.01.014