Influência da adição de diatomita em pastas geopoliméricas para poços de petróleo

Abstract

Cementation is a common practice in the oil industry, and have fundamental importance in building a oil well. The development of this activity has promoted the search for suitable materials for cementing oil wells, seeking to improve the behavior of the pastes during cementing operations, as regards performance and longer life, thus supporting the requests required by national and international standards. In this work was studied the influence of the addition of diatomite in the properties of geopolymeric pastes based on metakaolin. The use of a new raw material abundant in nature and low added value, the diatomite is another alternative source of silica in the production of geopolymers, being used as an additive for improving some properties. The objective of this work was to study how the characteristics physical, chemical and mineralogical of diatomite influence the geopolymerization reactions, as well as the characteristics of geopolymers. The effect of the addition of diatomite in the properties of the geopolymeric pastes has been evaluated, comparing them with the properties of the geopolymer based on metakaolin. For the development of this study were prepared light geopolymeric pastes, with different concentrations of diatomite. To analyze the effect of these concentrations of diatomite in geopolymeric pastes were performed rheology tests, fluid loss control, free water, density, thickening time, compressive strentgth. Also presented results of x-ray diffraction (XRD), scanning electron microscopy (SEM) and Thermal analysis (TG) to gather information for a better understanding of the microstructure of geopolymeric cement. The results showed that the addition of diatomite changed appreciably microstructure and drastically the rheological and mechanical properties of the geopolymeric pastes, functioning as accelerator effect, reducing the thickening time of the pastes. Increasing the concentration of diatomite, it was observed that rheological parameters increase, but decreases fluid loss control volume, independent of the temperature studied. When evaluating the compressive strentgth, was verified that the addition of diatomite led gains of up to 67%, this property, compared with the paste based on metakaolin.