Exploration of shale gas has indeed changed the dynamics of the petroleum industry. Efficient drilling in shale bearing zones largely depends on the nature of drilling fluid that are used. Non-damaging drilling fluid (NDDF) has emerged as an important class of drilling fluids over the last decade due to its superior inhibitive nature that yields better wellbore conditioning, especially in formations where the shale content is very high. However, the thermal stability of this biopolymer-based drilling fluid has posed limitations in its application in moderate to high-temperature wells. This research presents comprehensive rheological, fluid-loss and computational fluid dynamics (CFD) analysis to study and quantify the effects of zinc oxide nanoparticle (ZnO NP) on the NDDF. It was found that ZnO NP enhances thermal stability by yielding a viscosity over 300% than that of the base NDDF at 80 °C. These NPs also induces viscoelastic solid property that nurtures superior gel forming and thixotropic ability. Furthermore, more than 80% the viscous structure is regained within a timeframe of 180 s with the addition of 0.8 and 1 wt% ZnO NP as compared to 44% for the base NDDF. With the addition of 1 wt% ZnO NP the operating temperature of NDDF reaches up to 100 °C. Besides, fluid-loss of NDDF is reduced by 49% with doping of 1 wt% ZnO NP in NDDF. CFD simulations show excellent cutting carrying capacity of ZnO NP NDDFs with 1 wt% concentration showing a reduction in cutting retention by 29.13% at high temperatures (80 °C). Furthermore, the velocity profile showed that skewness in case of ZnO NP NDDF is reduced, indicating a better sweep of cuttings in the annular region. Despite exhibiting viscoelastic properties, the pressure drop of ZnO NP NDDFs along a complex wellbore geometry was within an acceptable range, ensuring flowability.

页岩气的勘探确实改变了石油工业的动力。页岩轴承区的高效钻井很大程度上取决于所用钻井液的性质。在过去的十年中，非破坏性钻井液（NDDF）已成为一类重要的钻井液，这是由于其优越的抑制性，可产生更好的井眼调节效果，尤其是在页岩含量很高的地层中。但是，这种基于生物聚合物的钻井液的热稳定性限制了其在中至高温井中的应用。这项研究提供了综合的流变，流体损失和计算流体动力学（CFD）分析，以研究和量化氧化锌纳米颗粒（ZnO NP）对NDDF的影响。已经发现，ZnO NP通过在80°C下获得比基础NDDF高300％以上的粘度来增强热稳定性。这些NPs还诱导了粘弹性固体性质，从而培养出优异的凝胶形成和触变性。此外，在180 s的时间内，通过添加0.8和1 wt％的ZnO NP可以恢复超过80％的粘性结构，而基础NDDF则为44％。加入1 wt％的ZnO NP，NDDF的工作温度可达100°C。此外，通过在NDDF中掺杂1 wt％的ZnO NP，NDDF的流体损失减少了49％。CFD仿真显示，浓度为1 wt％的ZnO NP NDDF具有出色的切削承载能力，在高温（80°C）下切削保持力降低了29.13％。此外，速度曲线显示，ZnO NP NDDF的偏斜度降低了，表示在环形区域中钻屑的扫掠效果更好。尽管表现出粘弹性，但ZnO NP NDDF沿复杂井眼几何结构的压降仍在可接受的范围内，从而确保了流动性。