Aplicação de microemulsão como colchão lavador de fluido não aquoso

Abstract

One of the most important steps in the search for oil is drilling process. During this step are uses drilling fluids to assist the removal of the generated fragments. When the drilling fluid is circulated through the well and returns by the annular space, formed a thin film with low permeability called filter cake. In the cementation step the removal of the filter cake and the drilling fluid is required to ensure the success of the operation, where are employed special fluids for this, denominated mattress washer and spacers. This way, this study aims to obtain a mattress washer that can solubilize the filter cake formed in the shaft wall to improve the adhesion of the cement in the rock surface by studying the behavior of anionic and nonionic surfactants, in the presence of salts. Were studied three surfactants, an anionic (SDS), a cationic (DAC) and a nonionic (Ultrol L100) in different aqueous phases, determining their microemulsion regions. The characterization of the systems was performed using the rheological study and measures of surface tension and droplet diameter. It was also carried out a test for the removal efficiency from the mattress washer developed by M12 method, contained in PROCELAB. The results showed that the surfactant who showed the best performance was DAC, that when was characterized by rheological study, surface tension and droplet diameter, presented favorable results for their application as mattress washer. The removal efficiency test showed that the mattress washer developed is quite efficient in the removal from the oil based drilling fluid, getting efficiency values of 100%.