Techniques of petrographic thin sectlon and pore cast preparation at Petrobras

Abstract

Most recent major progress in sedimentary petrology and the study of reservoir rocks has been a product of the evolution of sample preparation and petrographic analysis techniques. The simple impregnation of rock with stained resins for making thin-sections has afforded important developments in our knowledge ofthe geometry and genetic; evolution of the pore systf]ms of reservoir rocks, as well as in the application of sophisticated analytical techniques (such as microprobe,cathodoluminescence, and fluid inclusions) to the porous, commonly friablesedimentary rocks. This paper summarizes a technique for the preparation ofthin-sections and pore casts (made by acid dissolution of rock minerais following impregnation) developed at the laboratory of the Petrobras  Research Center(CENPES). The aim was to develop simple impregnation procedures using liquid vaseline. The procedures, materiaIs, and equipment are accessible for small laboratories but result in a substantial quality increase over conventional preparation systems.