Tan Jingpeng, Li Zhijun, Zhao Gan, Guo Guangding, Zhang Hao, Wang Sheng
State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (Chengdu University of Technology), Chengdu, Sichuan 610059, People's Republic of China.
Chengdu University of Technology, College of Environment and Civil Engineering, Chengdu, Sichuan 610059, People's Republic of China.
ACS Omega. 2024 Jul 24;9(31):33900-33911. doi: 10.1021/acsomega.4c03912. eCollection 2024 Aug 6.
In the geological core drilling industry, simple and low-cost drilling fluid formulations are required that are easy to apply and maintain. Currently, drilling fluid systems with simple formulations generally exhibit poor performance and do not satisfy the requirements of complex formations. The application of powder surface modification technology has been extensively investigated in several fields; however, few are the studies focusing on the modification of bentonite. Consequently, in this study, based on the surface modification technology of powders, bentonite is modified using the modifiers ZJ-1 and ZJ-2, giving it the characteristic of "one additive with multiple functions". This allows the construction of a new type of drilling fluid system with a simple formulation (water + modified bentonite), excellent performance, and easy application and maintenance. First, a new composite modification method named the dissolution and extrusion composite modification method was proposed, and the dosage of the modifier and the optimal ratio of each modifier were determined experimentally. Second, orthogonal design experiments were conducted to determine the optimal preparation conditions based on the rheological properties of the drilling fluid, dynamic plastic ratio, and filtration loss. Subsequently, the performance of the modified bentonite drilling fluid was analyzed by comparing it to that of a regular bentonite drilling fluid. Finally, the modification mechanism of bentonite was analyzed using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). It was revealed that a total modifier dosage of 2% and a ratio of ZJ-1 to ZJ-2 of 1.5:0.5 afforded a modified bentonite drilling fluid with significantly enhanced performance compared to a regular bentonite drilling fluid. The modified bentonite exhibited a filtration loss of 7.5 mL, funnel viscosity of 51.5 s, static shear force of 2.5 Pa, dynamic shear force of 9.198 Pa, apparent viscosity of 29 mPa·s, and plastic viscosity of 20 mPa·s. The experimental repeatability was good, and the optimal preparation conditions for modified bentonite involved a reaction time of 10 h, a reaction temperature of 100 °C, and a mechanical pressure of 0.5 MPa. Microscopic analysis showed that the modifiers were incorporated into bentonite through intercalation and surface adsorption and that the modified bentonite can form a dense filter cake. Our study provides a new drilling fluid solution for the geological core drilling industry, effectively promoting the advancement of drilling fluid technologies.
在地质岩心钻探行业中，需要简单且低成本的钻井液配方，这些配方易于应用和维护。目前，配方简单的钻井液体系通常性能较差，无法满足复杂地层的要求。粉末表面改性技术在多个领域已得到广泛研究；然而，专注于膨润土改性的研究却很少。因此，在本研究中，基于粉末表面改性技术，使用改性剂ZJ - 1和ZJ - 2对膨润土进行改性，使其具有“一剂多功能”的特性。这使得能够构建一种配方简单（水 + 改性膨润土）、性能优异且易于应用和维护的新型钻井液体系。首先，提出了一种名为溶解与挤压复合改性法的新型复合改性方法，并通过实验确定了改性剂的用量以及各改性剂的最佳比例。其次，基于钻井液的流变性能、动塑比和滤失量进行正交设计实验，以确定最佳制备条件。随后，通过将改性膨润土钻井液与常规膨润土钻井液进行比较，分析了改性膨润土钻井液的性能。最后，利用傅里叶变换红外光谱（FTIR）、X射线衍射（XRD）和扫描电子显微镜（SEM）分析了膨润土的改性机理。结果表明，与常规膨润土钻井液相比，总改性剂用量为2%且ZJ - 1与ZJ - 2的比例为1.5:0.5时，改性膨润土钻井液的性能得到显著增强。改性膨润土的滤失量为7.5 mL，漏斗粘度为51.5 s，静切力为2.5 Pa，动切力为9.198 Pa，表观粘度为29 mPa·s，塑性粘度为20 mPa·s。实验重复性良好，改性膨润土的最佳制备条件为反应时间10 h、反应温度100℃和机械压力0.5 MPa。微观分析表明，改性剂通过插层和表面吸附进入膨润土，且改性膨润土可形成致密的滤饼。我们的研究为地质岩心钻探行业提供了一种新的钻井液解决方案，有效推动了钻井液技术的进步。
