Huang Shengming, Dong Tengfei, Jiang Guancheng, Yang Jun, Yang Xukun, Wang Quande
College of Petroleum Engineering, Ministry of Education (MOE) Key Laboratory of Petroleum Engineering, China University of Petroleum (Beijing), Beijing 102249, China.
State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum (Beijing), Beijing 102249, China.
Gels. 2024 Aug 1;10(8):505. doi: 10.3390/gels10080505.
Addressing the high friction and torque challenges encountered in drilling processes for high-displacement wells, horizontal wells, and directional wells, we successfully synthesized OAG, a high-temperature and high-salinity drilling fluid lubricant, using materials such as oleic acid and glycerol. OAG was characterized through Fourier-transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). The research findings demonstrate the excellent lubricating performance of OAG under high-temperature and high-salinity conditions. After adding 1.0% OAG to a 4% freshwater-based slurry, the adhesion coefficient of the mud cake decreased to 0.0437, and at a dosage of 1.5%, the lubrication coefficient was 0.032, resulting in a reduction rate of 94.1% in the lubrication coefficient. After heating at 200 °C for 16 h, the reduction rate of the lubrication coefficient reached 93.6%. Even under 35% NaCl conditions, the reduction rate of the lubrication coefficient remained at 80.3%, indicating excellent lubrication retention performance. The lubricant OAG exhibits good compatibility with high-density drilling fluid gel systems, maintaining their rheological properties after heating at 200 °C and reducing filtration loss. The lubrication mechanism analysis indicates that OAG can effectively adsorb onto the surface of N80 steel sheets. The contact angle of the steel sheets increased from 41.9° to 83.3° before and after hot rolling, indicating a significant enhancement in hydrophobicity. This enhancement is primarily attributed to the formation of an extreme-pressure lubricating film through chemical reactions of OAG on the metal surface. Consequently, this film markedly reduces the friction between the drilling tools and the wellbore rocks, thereby enhancing lubrication performance and providing valuable guidance for constructing high-density water-based drilling fluid gel systems.
针对大位移井、水平井和定向井钻井过程中遇到的高摩擦和高扭矩挑战，我们成功地使用油酸和甘油等材料合成了一种高温高盐钻井液润滑剂OAG。通过傅里叶变换红外光谱（FTIR）和热重分析（TGA）对OAG进行了表征。研究结果表明，OAG在高温高盐条件下具有优异的润滑性能。在4%的淡水基泥浆中加入1.0%的OAG后，泥饼粘附系数降至0.0437，用量为1.5%时，润滑系数为0.032，润滑系数降低率达94.1%。在200℃加热16小时后，润滑系数降低率达到93.6%。即使在35%NaCl条件下，润滑系数降低率仍保持在80.3%，表明具有优异的润滑保持性能。润滑剂OAG与高密度钻井液凝胶体系具有良好的相容性，在200℃加热后仍能保持其流变性能并降低滤失量。润滑机理分析表明，OAG能有效吸附在N80钢板表面。热轧前后钢板的接触角从41.9°增加到83.3°，表明疏水性显著增强。这种增强主要归因于OAG在金属表面通过化学反应形成了极压润滑膜。因此，该膜显著降低了钻具与井壁岩石之间的摩擦，从而提高了润滑性能，为构建高密度水基钻井液凝胶体系提供了有价值的指导。
