Evaluation of mineral and organic inhibitor effects on bentonite clay

Abstract

The supra-salt complex of the oilfield of the Republic of Belarus is represented by high-colloidal multicolored clay deposits with layers of unstable sandstones and aleurolites evenly distributed throughout the section. Drilling of intervals which are represented by clay sediments is accompanied by complications caused by swelling of clays – stuck, tightening, sticking clay on the drilling tool. Swelling occurs during drilling of high-colloidal clays. As a result of the action of the drilling mud and its filtrate, the clay swells, narrowing the trunk and reducing the stability of the walls of well. For the prevention or maximum reduction of the intensity of the swelling the drilling mud must have a high inhibitory ability. Such properties are attached by special reagents-inhibitors, which are the main component of the inhibiting drilling fluid. The creation of such drilling fluid is advisable to start with the choice of the reagent-inhibitor. This article provides a comparison of the inhibitory effect of the two reagents specific to organic (Polyekol) and inorganic (potassium chloride) compounds. To assess the effectiveness of these reagents, the indicator of moisturizing ability was used. In the experiment, the highest efficiency demonstrated organic reagentinhibitor Polyekol at a concentration of 2%, and the inorganic reagent-inhibitor potassium chloride resulted in cracking of samples. The results obtained during the comparison of these reagents will form the basis for the development of an inhibiting drilling mud for drilling of the supra-salt deposits of the Pripyat trough.