SOUSA, A. P. O.; http://lattes.cnpq.br/8039311999177696; SOUSA, Ana Paula de Oliveira.
Resumen:
Problems related to the instability of oil wells such as agglomeration and
accretion of cuttings lead to an increase in non-productive time in the operation of
drilling, and careful selection of drilling fluid components can
help to reduce the potential of this phenomenon, since the interactions between the formations and
The fluid can be regulated to increase and improve wellbore stability. Of this
In this way, the present work aims to carry out an analysis of the interaction between
expandable minerals present in reactive formations and based drilling fluids
of glycerin, in the conception and extension of the phenomenon of accretion in oil wells.
Therefore, the accretion capacity of bentonite pellets was evaluated, which have
a high content of expandable clay minerals, with the use of drilling fluids
based on glycerin with different types of inhibitors in its composition. The study
was carried out in three stages: in the first, the pellets were characterized by means of the
x-ray diffraction (DXR) and Atterberg indices; in the second, the fluids of
perforation were characterized through the rheological study; and in the third stage it was
evaluated the interaction between the expandable minerals present in the pellets and the fluids
drilling holes studied through accretion tests. The obtained results
revealed that the pellets studied are predominantly composed of
illite-smectite (I-S) interstratified clay minerals, and are classified as
highly plastic, characteristics that show the nature of the sample to be reactive
with a high degree of expansion. Furthermore, the percentages of accretion were significant
for all fluids studied. Therefore, it was concluded that the use of glycerin
in drilling fluids did not provide mineral stabilization capacity
expandable elements present in reactive formations, even with the use of different
types of expansion inhibitors, which were not satisfactory in reducing
of the effects of rock expansion.
