粘土防膨剂性能评价的新方法研究

New Method for Evaluating the Performance of Clay-swelling Stabilizer

粘土矿物的水化膨胀是导致钻井井壁失稳和储层损害的根本原因,粘土矿物防膨评价方法对于正确使用粘土防膨剂具有重要意义;分析并综述了粘土防膨剂试验结果评价方法及其特点;提出用激光粒度仪法研究粘土防膨的新方法,其基本特点是粘土矿物在不同介质中作用后其粒径分布存在明显差别,粘土颗粒越小,防膨能力越强;研究表明:粘土矿物经粘土防膨剂作用后其粒径明显小于蒸馏水;有机阳离子防膨剂防膨效果要优于无机盐类防膨剂;试验结果证明:激光粒度仪法来评价粘土防膨剂效果的方法是可行的,且其速度快、直观,与离心膨胀法评价方法所得结果比较一致。

Hydration swelling of clay minerals was an essential reason for borehole instability and formation damage,the method for evaluating the swelling inhibition was of great significance for correct use of swelling stabilizer.The result of testing,the evaluation method and its characteristics were analyzed and reviewed.A new method by using laser particle size analyzer for evaluating swelling inhibition was presented.The principle was that particle size distribution of clay mineral was different after treating in different media;the smaller clay particle was,the stronger the anti-swelling ability was.The results show that particle size of clay mineral become smaller than that of distilled water after it is treated by using the swelling stabilizer,the effect of organic cationic agent is higher than that of inorganic salt.Moreover,the results by using laser particle size analyzer is consistent with that of centrifuge method.The method by using laser particle size analyzer is feasible.