The filter-cake has a critical role in temporarily reducing the permeability of the wellbore to prevent issues such as lost circulation, formation damage, wellbore collapse and differential sticking. The filter-cake's ability to perform these functions may be impaired by its deterioration caused by the circulation of fluid, swabbing or mechanical interaction. Therefore, being able to measure the strength of the filter-cake, and hence its ability to withstand disturbances, is important to ensure optimal drilling fluid design.Two water-based reservoir drilling fluids were used to produce filter-cakes under high differential pressures. The filter-cakes were thereafter analysed using a rheometer with a specially designed cell for accurate powder shear rheology. This enabled measurement of the cohesive strength and flowability of the filter-cakes.It was found that filter-cakes composed of a conventional reservoir drilling fluid with CaCO₃ and polymers, showed low cohesive strength and high flowability. The other fluid, which contained cellulose-based fibres in addition to CaCO₃ and polymers, showed much higher cohesion and lower flowability.It was concluded that the test methodology could be very useful in relation to optimising drilling fluid design, particularly for wells were lost circulation, wellbore stability and differential sticking may be relevant problems. It was also concluded that the addition of cellulose-based fibres may significantly increase the filter-cake strength in a water-based drilling fluid.

滤饼在暂时降低井筒渗透率以防止井漏、地层损坏、井筒坍塌和压差卡钻等问题方面具有关键作用。滤饼执行这些功能的能力可能会因流体循环、擦拭或机械相互作用引起的劣化而受损。因此，能够测量滤饼的强度及其承受干扰的能力，对于确保优化钻井液设计非常重要。使用两种水基油藏钻井液在高压差下生产滤饼。然后使用流变仪分析滤饼，该流变仪具有专门设计的用于精确粉末剪切流变学的单元。这使得能够测量滤饼的内聚强度和流动性。₃和聚合物，表现出低内聚强度和高流动性。另一种流体，除了 CaCO ₃和聚合物外，还含有纤维素基纤维，表现出更高的内聚力和更低的流动性。得出的结论是，该测试方法对于优化钻井液设计非常有用，特别是对于失水井循环、井筒稳定性和差异卡住可能是相关问题。还得出结论，添加纤维素基纤维可显着提高水基钻井液中的滤饼强度。