Modifications of the muds intended for HDD considering drilling through clay rocks - potassium chloride

The article describes issue of clay hydration phenomenon during Horizontal Directional Drilling. Reducing hydration, hence swelling, is a great concern in light of borehole wall stability maintenance. Muds commonly used for drilling by abovementioned technique are often blend of unknown ingredients. Thus, it should be carefully tested for addition of hydration inhibitors at the early stage of mud formula preparation. The paper includes research formula and results of technological parameters of modified HDD mud. Moreover, there were conducted tests of QSE Pellets swelling and linear swelling of test samples collected from boreholes drilled by HDD technique.