Avaliação da viabilidade da glicerina como fase polar de uma emulsão de glicerina em olefina para perfuração de poços de petróleo

Abstract

The drilling in ultra-deep waters presents a series of difficulties and specificities, related to the depth of the well, water depth, high pressures and salt formations found in the pre-salt basins. Moreover, there is still a need to use fluids in compliance to environmental legislation for cleaning and disposing of cuttings at sea. In this sense, inverted emulsion fluids, from brine in olefin, are favorable and have been used extensively for this application. The fluids need to maintain their rheological properties throughout the entire drilling, also considering the variation of temperature, in order to minimize the formation of hydrates, interaction with clayey areas, interaction with saline zones and damage to the formation. The hypothesis of this thesis is that the substitution of brine for glycerin can promote the maintenance of rheological properties, as well as mitigate the interaction with clay and salt zones, not potentiate the formation of hydrates and give a destination to a residue from the production of biodiesel. For this purpose, in the preliminary study, the physical-chemical characteristics of the dispersed phase and the continuous medium were studied for application in an emulsified system of glycerin in olefin. Keeping in mind the initial characteristics, the emulsified system was applied as a drilling fluid, using commercial additives and comparing the rheological responses varying the temperature. The interaction with saline and clay zones was investigated by assessing the interaction of the dispersed phase and the continuous medium using clay and salt plugs. Among the main results, the glycerin obtained as a by-product of biodiesel was compatible with the commercial additives used in drilling fluids based on brine in olefin, demonstrating the feasibility of immediate application in drilling fluids, given the maintenance of rheological properties, decreasing the volume of filtrate and less reactivity towards salt and clay areas. In this way, the thesis presented a new composition of drilling fluid in ultra-deep waters, with the potential to minimize damage to the rock formation, through the use of a residue from the biodiesel production industry, without the need for previous treatments.