Zhou Guowei, Zhang Xin, Yan Weijun, Qiu Zhengsong
CNPC Greatwall Drilling Company, 101 Anli Road, Chaoyang District, Beijing 100101, China.
Petroleum Engineering Institute, Qingdao Campus, China University of Petroleum (East China), No.66 Changjiang East Road, Huangdao District, Qingdao 266000, China.
Gels. 2025 May 22;11(6):378. doi: 10.3390/gels11060378.
To address the technical challenge of high polymer gel viscosity reducers losing viscosity at elevated temperatures and difficulty in controlling fluid loss, a polymer-based nano calcium carbonate composite high-temperature tackifier named GW-VIS was prepared using acrylamide (AM), 2-acrylamido-2-methylpropanesulfonic acid (AMPS), N-vinylpyrrolidone (NVP), and nano calcium carbonate as raw materials through water suspension polymerization. This polymer gel can absorb water well at room temperature and has a small solubility. After a long period of high-temperature treatment, most of it can dissolve in water, increasing the viscosity of the suspension. The structure of the samples was characterized by infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy, and their performance was evaluated. Rheological tests indicated that the 0.5% water suspension had a consistency coefficient (k = 761) significantly higher than the requirement for clay-free drilling fluids (k > 200). In thermal resistance experiments, the material maintained stable viscosity at 180 °C (reduction rate of 0%), and only decreased by 14.8% at 200 °C. Salt tolerance tests found that the viscosity reduction after hot rolling at 200 °C was only 17.31% when the NaCl concentration reached saturation. Field trials in three wells in the Liaohe oilfield verified that the clay-free drilling fluid supported formation operations successfully. The study shows that the polymer gel has the potential to maintain rheological stability at high temperatures by forming a network structure through polymer chain adsorption and entanglement, with a maximum temperature resistance of up to 200 °C, providing an efficient drilling fluid for deep oil and gas well development. It is feasible to select nano calcium carbonate to participate in the research of high-temperature resistant polymer materials. Meanwhile, the combined effect of monomers with large steric hindrance and inorganic materials can enhance the product's temperature resistance and resistance to NaCl pollution.
为解决高分子凝胶降黏剂在高温下失去黏性以及控制滤失困难的技术挑战，以丙烯酰胺（AM）、2-丙烯酰胺基-2-甲基丙磺酸（AMPS）、N-乙烯基吡咯烷酮（NVP）和纳米碳酸钙为原料，通过水悬浮聚合法制备了一种聚合物基纳米碳酸钙复合高温增黏剂GW-VIS。这种聚合物凝胶在室温下能很好地吸水且溶解度小。经过长时间高温处理后，大部分能溶解于水，增加悬浮液的黏度。通过红外光谱、热重分析和扫描电子显微镜对样品结构进行了表征，并对其性能进行了评价。流变学测试表明，0.5%的水悬浮液的稠度系数（k = 761）显著高于无黏土钻井液的要求（k > 200）。在耐热性实验中，该材料在180℃时黏度保持稳定（降低率为0%），在200℃时仅降低14.8%。耐盐性测试发现，当NaCl浓度达到饱和时，在200℃热轧后的黏度降低仅为17.31%。在辽河油田的三口井进行的现场试验证实，无黏土钻井液成功地支持了地层作业。研究表明，该聚合物凝胶通过聚合物链的吸附和缠结形成网络结构，具有在高温下保持流变稳定性的潜力，最高耐温可达200℃，为深层油气井开发提供了一种高效的钻井液。选择纳米碳酸钙参与耐高温聚合物材料的研究是可行的。同时，空间位阻大的单体与无机材料的协同作用可提高产品的耐高温性和抗NaCl污染能力。
