井壁化学稳定性综合评价模型及其应用

利用考核井壁化学稳定性的膨胀量、分散率、CST值、CEC值、电位，比表面积、页岩稳定指数、胶体率、比吸水量和粒度等指标。在对多个岩样进行稳定性评价的基础上。分析了不同评价方法之闻的相关性，对目前井壁稳定性多指标综合评价存在的问题进行了分析。为克服井壁稳定性多指标综合评价方法的不足．介绍了一种新的分析法——主成分分析法．并编制了用该方法确定井壁稳定性的计算机软件。使井壁稳定性评价科学化、合理化。评价结果证明，新的井壁化学稳定性评判模型——主成分分析法是可行的，只要搜集的岩样层位准确，选择的测试方法合理，测试数据无误，可对不同深度井壁的相对化学稳定性作出评判；该方法运算简便，结果可靠。适用于评价井壁的化学稳定性．

Evaluation model of borehole chemical stability and its application

The relativities of different methods for evaluating borehole chemical stability and the problems of multiple-parameters existing in evaluating borehole chemical stability were studied based on the measuring results of about seventy shale samples and borehole chemical stability evaluation parameters such as expansion, dispersion ratio, CST and CEC values, potential fall, specific surface area, shale stability index, colloidal fraction, specific absorption and particle size distribution. A new model of borehole chemical stability evaluation-principle component analysis method was recommended to overcome the problems of multiple-parameters evaluation and the computer software for evaluating borehole stability was developed. Application shows that the method is simple and reliable to evaluate borehole chemical stability and it can be used to evaluate the relative borehole chemical stability in different depth as long as stone samples were collected accurately and testing ways were reasonable, as well as the testing data were inerrable.