EMULSION DRILLING MUDS BASED ON DIESEL FUEL AND MAGNESIUM HYDROGELS
This paper deals with obtaining drilling muds as II-type hydrophobic emulsions due to the cooperative dispersion of diesel fuel (organic phase) and inorganic magnesium hydrogels (water phase) and to weighting them up to the required density with magnesium and sodium salts (condensed mud solids). We have identified their physicochemical properties, such as density, relative viscosity, pH, and structural-mechanical and rheological properties, and assessed their kinetic stability. Functions of emulsifiers and stabilizers were performed by cationic and non-ionic water- and oil-soluble surfactants, the superficial tension of which was measured using the relevant tension-measuring method. To obtain efficient emulsion drilling muds, it is recommended to use magnesium chloride hexahydrate (8÷15 % wt.) as the core salt-saturating and structure-forming component. It is found that the most stable emulsions are those, in which the water-phase-to-organic-phase ratios are 35/65 и 45/55 and the magnesium-chloride-hexahydrate-to-alkaline ratio is 3:1. The systems obtained are promising in terms of using them in processing conditions, where the solutions are required that have low density of ≤1250 kg/m<sup>3</sup>, such as horizontal drilling of wells. Developing hydrophobic colloid emulsion systems can be further used by the specialists at research and engineering centers and drilling services to enhance the quality, efficiency, and environmental safety of operations at oil-producing facilities.