Sui Yu, Guo Tianyue, Li Dan, Guo Da, Zhang Zhiqiu, Cao Guangsheng
Key Laboratory of Enhanced Oil Recovery, Ministry of Education, College of Petroleum Engineering, Northeast Petroleum University, Daqing 163318, China.
School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
Molecules. 2023 Oct 11;28(20):7036. doi: 10.3390/molecules28207036.
Successful exploitation of carbonate reservoirs relies on the acid-fracturing process, while the thickeners used in this process play a key role. It is a common engineering problem that thickeners usually fail to function when used in high-temperature environments. Until now, no research has ventured into the field of synthesizing thickeners which can be effectively used at ultra-high temperatures up to 180 °C. In our current study, a novel high-temperature-resistant polyacrylamide thickener named SYGT has been developed. The thermal gravimetric analysis (TGA) reveals that SYGT is capable of withstanding temperatures of up to 300 °C. Both our scanning electron microscopy (SEM) and rheological analysis demonstrate that the SYGT exhibits excellent resistance to both temperature and shear. At 180 °C, the viscosity of the SYGT aqueous solution is no lower than 61.7 mPa·s at a 20% H concentration or high salt concentration, and the fracture conductivity of the thickened acid reaches 6 D·cm. For the first time, the influence of the polymer spatial network's structural parameters on the viscosity of polymer solutions has been evaluated quantitatively. It was discovered that the length and surrounding area of the SNS skeleton have a synergistic effect on the viscosity of the polymer solution. Our experiments show that SYGT effectively reduces the acid-rock reaction rate and filtration loss under harsh working conditions such as high temperature, strong shear, high salinity, and a high concentration of acid. The synthesized acid-fracturing thickener (SYGT) has wide application potential in the development of carbonate reservoirs under high-temperature conditions.
碳酸盐岩储层的成功开采依赖于酸压裂工艺，而该工艺中使用的增稠剂起着关键作用。增稠剂在高温环境下使用时通常失效，这是一个常见的工程问题。到目前为止，还没有研究涉足合成能在高达180℃的超高温下有效使用的增稠剂领域。在我们目前的研究中，开发了一种新型的耐高温聚丙烯酰胺增稠剂SYGT。热重分析（TGA）表明，SYGT能够承受高达300℃的温度。我们的扫描电子显微镜（SEM）和流变学分析均表明，SYGT表现出优异的耐温性和抗剪切性。在180℃时，SYGT水溶液在20% H浓度或高盐浓度下的粘度不低于61.7 mPa·s，增稠酸的裂缝导流能力达到6 D·cm。首次定量评估了聚合物空间网络结构参数对聚合物溶液粘度的影响。发现SNS骨架的长度和环绕面积对聚合物溶液的粘度具有协同作用。我们的实验表明，SYGT在高温、强剪切、高盐度和高酸浓度等恶劣工作条件下能有效降低酸岩反应速率和滤失量。合成的酸压裂增稠剂（SYGT）在高温条件下碳酸盐岩储层开发中具有广阔的应用潜力。
