Ma Jingyuan, Pang Shaocong, Zhang Zenan, Xia Boru, An Yuxiu
School of Engineering and Technology, China University of Geosciences (Beijing), Haidian District, Beijing 100083, China.
Key Laboratory of Deep Geo Drilling Technology, Ministry of Land and Resources, Beijing 100083, China.
ACS Omega. 2021 Mar 30;6(14):9750-9763. doi: 10.1021/acsomega.1c00374. eCollection 2021 Apr 13.
The wellbore instability caused by the penetration of drilling fluids into the formation is a vital problem in the drilling process. In this study, we synthesized a polymer/graphene oxide composite (PAAN-G) as a fluid loss additive in water-based drilling fluids. The three monomers (acrylamide (AM), 2-acrylamide-2-methyl-1-propane sulfonic acid (AMPS), -vinylpyrrolidone (NVP)) and graphene oxide (GO) were copolymerized using aqueous free radical polymerization. The composition, micromorphology, and thermal stability properties of PAAN-G were characterized by Fourier transform infrared (FT-IR) spectroscopy and thermogravimetric analysis (TGA). According to the American Petroleum Institute (API) standards, the influence of PAAN-G on the rheological and filtration properties of bentonite-based mud was evaluated. Compared with PAAN, PAAN-0.2G has more stable rheological properties at high temperatures. The experimental results showed that even at a high temperature of 240 °C, PAAN-G can still maintain a stable fluid loss reduction ability. In addition, PAAN-G is also suitable for high-salt formations; it can still obtain satisfactory filtration volume when the concentration of sodium chloride (NaCl) and calcium chloride (CaCl) reached 25 wt %. Besides, we discussed the fluid loss control mechanism of PAAN-G through particle size distribution and scanning electron microscopy (SEM).
钻井液侵入地层导致的井眼失稳是钻井过程中的一个关键问题。在本研究中，我们合成了一种聚合物/氧化石墨烯复合材料（PAAN-G）作为水基钻井液中的降滤失剂。使用水溶液自由基聚合法将三种单体（丙烯酰胺（AM）、2-丙烯酰胺-2-甲基-1-丙烷磺酸（AMPS）、N-乙烯基吡咯烷酮（NVP））与氧化石墨烯（GO）进行共聚。通过傅里叶变换红外（FT-IR）光谱和热重分析（TGA）对PAAN-G的组成、微观形态和热稳定性进行了表征。根据美国石油学会（API）标准，评估了PAAN-G对膨润土基泥浆流变学和过滤性能的影响。与PAAN相比，PAAN-0.2G在高温下具有更稳定的流变性能。实验结果表明，即使在240℃的高温下，PAAN-G仍能保持稳定的降滤失能力。此外，PAAN-G也适用于高盐地层；当氯化钠（NaCl）和氯化钙（CaCl）浓度达到25 wt%时，它仍能获得令人满意的滤失量。此外，我们通过粒度分布和扫描电子显微镜（SEM）讨论了PAAN-G的降滤失控制机理。
