Onawole Abdulmujeeb T, Hussein Ibnelwaleed A, Saad Mohammed A, Ismail Nadhem, Alshami Ali, Nasser Mustafa S
Gas Processing Center, College of Engineering, Qatar University, Doha P.O. Box 2713, Qatar.
Chemical Engineering Department, College of Engineering, Qatar University, Doha P.O. Box 2713, Qatar.
Polymers (Basel). 2022 Jun 9;14(12):2333. doi: 10.3390/polym14122333.
The calcium carbonate (CaCO) scale is one of the most common oilfield scales and oil and gas production bane. CaCO scale can lead to a sudden halt in production or, worst-case scenario, accidents; therefore, CaCO scale formation prevention is essential for the oil and gas industry. Scale inhibitors are chemicals that can mitigate this problem. We used two popular theoretical techniques in this study: Density Functional Theory (DFT) and Ab Initio Molecular Dynamics (AIMD). The objective was to investigate the inhibitory abilities of mixed oligomers, specifically acrylamide functionalized silica (AM-Silica). DFT studies indicate that Ca does not bind readily to acryl acid and acrylamide; however, it has a good binding affinity with PAM and Silica functionalized PAM. The highest binding affinity occurs in the silica region and not the -CONH functional groups. AIMD calculations corroborate the DFT studies, as observed from the MD trajectory that Ca binds to PAM-Silica by forming bonds with silicon; however, Ca initially forms a bond with silicon in the presence of water molecules. This bonding does not last long, and it subsequently bonds with the oxygen atoms present in the water molecule. PAM-Silica is a suitable calcium scale inhibitor because of its high binding affinity with Ca. Theoretical studies (DFT and AIMD) have provided atomic insights on how AM-Silica could be used as an efficient scale inhibitor.
碳酸钙（CaCO₃）垢是最常见的油田垢之一，也是油气生产中的一大危害。碳酸钙垢可能导致生产突然停止，在最坏的情况下，还会引发事故；因此，预防碳酸钙垢的形成对油气行业至关重要。阻垢剂是能够缓解这一问题的化学物质。在本研究中，我们使用了两种常用的理论技术：密度泛函理论（DFT）和从头算分子动力学（AIMD）。目的是研究混合低聚物，特别是丙烯酰胺功能化二氧化硅（AM - 二氧化硅）的抑制能力。DFT研究表明，Ca不易与丙烯酸和丙烯酰胺结合；然而，它与聚丙烯酰胺（PAM）和二氧化硅功能化的PAM具有良好的结合亲和力。最高的结合亲和力出现在二氧化硅区域，而非 -CONH官能团。AIMD计算证实了DFT研究结果，从分子动力学轨迹可以观察到，Ca通过与硅形成键与PAM - 二氧化硅结合；然而，Ca最初在水分子存在的情况下与硅形成键。这种键合不会持续很长时间，随后它会与水分子中存在的氧原子结合。由于PAM - 二氧化硅与Ca具有高结合亲和力，它是一种合适的钙垢抑制剂。理论研究（DFT和AIMD）提供了关于AM - 二氧化硅如何用作高效阻垢剂的原子层面见解。
