Produção de cimento para poço de petróleo a partir de cimentos portland comerciais.

Abstract

The cement used in oil wells (CPP) is a Portland cement variation, with low celite content (C3A) and with larger grains than other common Portland cements. It's a very specific application cement, requiring greater production control, increasing the product costs and minimizing its production scale. The present research arose with objective to compose a cement for oil well from the cement mixture commonly found in the market (CP II, CP III e CP IV) that could replace the CPP when it is not available and the need for your immediate use exists. The cements CP II, CP III and CP IV were physics, chemical and mineralogical characterized through granulometry laser, X-ray diffraction, compression resistance and X-ray fluorescence tests. Then, they were subjected to quantitative analysis of phases through the Rietveld refinement by the Topas program and, through linear programming - Simplex Method - was determined the optimum mixture for the new cement composition. The new cement was characterized and compared with the specifications of the ABNT. The obtained results showed that the cements used as raw materiais conform to ABNT specifications. And that the new cement, called CPP Mixed, presented a composition (main phases contents) that attended NBR 9831 specifications, intended for special Portland cement for oil well with moderate sulphates resistance. The low content of C3A, presented by the new cement, retards the cement cure time, increasing the time that it can provide workability. However, the other characterizations results pointed that the CPP Mixed partially attended the expected values. With this, it was verified that can be viable the use of commercial cements mixtures for the production of oil well cement provided by a complementary research on this subject, as a way to demonstrate your qualities and technological applications.