The Impact Assessment of Plant Oils on Unctuousity of Drilling Fluids

Abstract

The object of study is natural oils. Lubricating additives based on natural substances – vegetable oils and animal fats – meet the increased requirements for environmental safety of materials used in the drilling process. Consumption of environmentally friendly lubricants is constantly growing and requires an expansion of the raw material base for their production. Therefore today lubricants are important drilling reagents. From the ecological point of view, lubricating additives based on vegetable oils are of the greatest interest. The main physicochemical properties of sunflower and castor vegetable oils and the influence of these lubricating additives on lubricating and rheological characteristics of drilling fluids were investigated. In addition, the main properties of water-clay drilling fluids were investigated and their main parameters were determined according to standard API methods. During the testing of the samples, we took into account, first of all, a shear rate of the filter cake (CFC). It is the value that characterizes the strength of filter cake and is determined by the ratio of strength necessary for the tangential displacement of cyclic load across the cake to its weight. It is the CFC that characterizes the lubricating properties of the samples of solutions with a lubricant additive of a certain concentration that were studied. It is the CFC that characterizes the lubricating properties of the samples of solutions with a lubricant additive of a certain concentration that were studied. Based on the above studies, it can be concluded that the addition of castor oil effectively reduces the coefficient of friction of the filtration crust formed from the studied drilling fluids (fresh, mineralized, and saline). The recommended concentrations of this oil to the drilling fluid are 0.5 %, 1 %, and 5 %. Sunflower oil has an effective effect on the saline solution, less effectively – on the mineralized with an oil concentration of 0.5 %, 3 %, and 5 %. On the basis of the conducted researches the prospects of use of sunflower and castor oils at development of a new compounding of a greasing additive to a drilling mud are defined. Further research is aimed at assessing their lubricity in the drilling fluid at the friction limit «metal-metal». It is planned to repeat the study at the Sticking Tester OFI (USA).