Płuczka wiertnicza z dodatkiem pochodnych alkoholi tłuszczowych

The article presents the results of research on the development of drilling muds containing derivatives of fatty alcohols, which will ensure that their optimal inhibitory properties in borehole conditions are achieved. In the mud compositions, alkoxy derivatives of fatty alcohols were used, which are non-ionic agents and their inhibitory properties have been confirmed in earlier studies. Drilling fluids were tested under HPHT conditions as well as under conditions of chemical contamination and increasing solids content. Due to the possibility of using muds containing new types of inhibitors to drill-in, studies on their effect on damage to reservoir rock permeability were also conducted. The use of a new type of inhibitor required the development of a methodology for controlling its content in the mud and a method for treating the mud during drilling. Previously used inhibitors of this type are polyglycols that are polymers of ethylene oxide or copolymers of ethylene oxide and propylene oxide differing in molecular weight. The main test confirming the inhibitory properties of scrubbers is the testing of clay rock dispersion, normally carried out under ambient conditions. This article describes dispersion studies under elevated temperature conditions to confirm the inhibitory properties of test agents under conditions similar to wellbore. Dispersion studies were additionally associated with swelling measurements, i.e. volumetric growth of clay rock in the drilling mud environment. Muds containing new types of polyglycols were also tested in borehole-like conditions: tests on the resistance of these muds to divalent metal ions (Ca2+ and Mg2+), solid phase contamination (ground Miocene shale imitating drill cuttings) and increased temperature. The subject matter presented in the article is the result of industry interest in the use of muds with the addition of this type of inhibitors. These agents have similar properties to the previously used polyglycols, but show greater efficiency under well conditions.