优选钻井液中暂堵剂颗粒尺寸的理想充填新方法

New Method for Optimizing Particle Size of Bridging Agents in Drilling Fluids

应用颗粒堆积效率最大值原理阐述了优选钻井液中暂堵剂颗粒尺寸的"理想充填"理论和D90规则,提出了一种特别有利于对中、高渗储层实施暂堵和保护的新方法。依据该方法研制、开发的配套软件能够根据相关地层参数,快速、准确地对具有不同粒径的暂堵剂产品按一定比例进行合理的复配组合。试验结果表明,优选出的复配暂堵方案能有效地形成致密泥饼,与传统方法相比,岩心的渗透率恢复值明显提高,从而能有效阻止钻井液中固相颗粒和滤液侵入油气层。现场试验证实,应用该项技术可取得十分理想的保护储层的效果。

On the basis of previous research,the 'Ideal Packing Theory' and the d90 rule used for optimizing the particle size distribution were elaborated by applying the principle of maximum of packing efficiency and a newly developed method which was beneficial for bridging and protecting median and high permeability formations particularly was proposed.The software developed according to this method could be used to select bridging agents with different particle sizes in a given proportion precisely and quickly based on the related parameters of formations.The experimental results indicate that the optimized mixture of several bridging agents can form compacted mud cake effectively and the restored permeability of core samples increases drastically compared with traditional methods,thus the invasion of particles and filtrate can be prevented effectively.It is demonstrated from field tests that the ideal effectiveness for controlling formation damage can be achieved by applying this technology.