钻井液造壁性对固井质量的影响

为更真实地考察水基钻井液与固井质量的关系，建立了评价固井第二界面胶结强度的新方法——人造岩心法。通过测定在聚磺钻井液中浸泡24h形成吸附层的铁棒和高温高压滤失实验后形成滤饼的人造岩心经3种不同方式处理后形成的第一、第二界面胶结强度，得出了造壁性影响固井质量的一般规律。研究表明，对铁棒上的吸附层和人造岩心上的滤饼进行部分清除后，两界面的胶结强度均高于未处理的铁棒和岩心与水泥浆的胶结强度；对铁棒和岩心采用特制的冲洗液进行冲洗后，两界面的胶结强度大为改善，比清除部分吸附层和虚滤饼的铁棒和岩心与水泥浆的胶结强度还高。

Effect of Wall-building of Drilling Muds on the Cement Job Quality

A new method evaluating the cementation strength of the second interface in the cement sheath was established to investigate the relation between water base mud and the cement job quality.This method,which is called the artificial core method,uses an iron rod on to which an absorbed layer formed in polymer-sulfonates mud in 24 hours,and an artificial core on to which an HTHP mud cake has been created.The adsorption layer on the iron rod and the mud cake on the core were treated with three different methods to form cement sheaths with different properties.Measurement of the cementation strengths of the first and the second interfaces in the cement sheaths revealed the way with which the wall-building characteristics of the muds affect the cement job quality.Our research shows that when part of the adsorption layer on the iron rod and the mud cake on the core is removed,the cementation strengths of the two interfaces are both higher than when the adsorption layer and the mud cake are intact.Cleaning of the iron rod and the core with a specially prepared washing fluid leading to a much higher cementation strength than when the iron rod and the core are not cleaned,and even higher than when part of the adsorption layer and the mud cake is cleaned.