Cellulose Nanoparticles as Modifiers for Rheology and Fluid Loss in Bentonite Water-based Fluids
Cellulose Nanoparticles as Modifiers for Rheology and Fluid Loss in Bentonite Water-based Fluids
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DOI：
10.1021/acsami.5b00498
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发表时间：
2015-03-04
影响因子：
9.5
通讯作者：
Wu, Yiqiang
中科院分区：
文献类型：
--
作者：
Li, Mei-Chun;Wu, Qinglin;Wu, Yiqiang
钻井液的流变特性和滤失特性是保证钻井作业成功的两个关键因素。本研究证明了纤维素纳米颗粒（CNP），包括微纤化纤维素（MFC）和纤维素纳米晶体（CNCs）在提高膨润土（BT）水基钻井液（WDF）的流变性和过滤性能的有效性。通过硫酸水解从MFC中分离CNCs。与MFC相比，所得CNCs具有更小的尺寸，更负的表面电荷，更高的水溶液中的稳定性，更低的粘度，和不太明显的剪切稀化行为。这些差异导致MFC/BT-和CNC/BT-WDF之间具有独特的微观结构。由于BT层、CNC和固定化水分子之间的强烈表面相互作用，CNC/BT-WDF形成了典型的“核-壳”结构。然而，在MFC/BT-WDF中没有形成类似的结构。结果表明，CNC/BT-WDF具有比BT和MFC/BT-WDF更优越的上级流变性能、更高的温度稳定性、更小的滤失量和更薄的滤饼。此外，聚阴离子纤维素（PAC）的存在下，进一步提高CNC/BT-WDF的流变和过滤性能，表明PAC和CNC之间的协同效应。
Rheological and filtration characteristics of drilling fluids are considered as two critical aspects to ensure the success of a drilling operation. This research demonstrates the effectiveness of cellulose nanoparticles (CNPs), including microfibrillated cellulose (MFC) and cellulose nanocrystals (CNCs) in enhancing the rheological and filtration performances of bentonite (BT) water-based drilling fluids (WDFs). CNCs were isolated from MFC through sulfuric acid hydrolysis. In comparison with MFC, the resultant CNCs had much smaller dimensions, more negative surface charge, higher stability in aqueous solutions, lower viscosity, and less evident shear thinning behavior. These differences resulted in the distinctive microstructures between MFC/BT- and CNC/BT-WDFs. A typical "core-shell" structure was created in CNC/BT-WDFs due to the strong surface interactions among BT layers, CNCs, and immobilized water molecules. However, a similar structure was not formed in MFC/BT-WDFs. As a result, CNC/BT-WDFs had superior rheological properties, higher temperature stability, less fluid loss volume, and thinner filter cakes than BT and MFC/BT-WDFs. Moreover, the presence of polyanionic cellulose (PAC) further improved the rheological and filtration performances of CNC/BT-WDFs, suggesting a synergistic effect between PAC and CNCs.