Microthermometry of carbonate rocks of the Hondita-Loma Gorda formations, Vereda Bomboná Sector, municipality of Palermo - Huila, Colombia. Microtermometría de rocas carbonatadas de las formaciones Hondita-Loma Gorda, sector vereda Bomboná, municipio de Palermo – Huila, Colombia

Abstract

Geochemical properties in the petroleum industry are used to understand the origin, migration, accumulation, and alteration of hydrocarbons in the basin that contains them. The formation temperature of the rocks of the petroleum system that may be in the hydrocarbon generation window is of utmost importance, as this is the main objective of this article.

    The present research used the technique of Microthermometry of fluid inclusions to recognize the formation temperature, homogenization, density, determine some basic physicochemical variables and the salinity of the fluid at the time of trapping, providing evidence about the history of different events in different geological environments in the evolution of the sedimentary basin where the Hondita and Loma Gorda formations belong.

    The Hondita and Loma Gorda formations extend along the Upper Magdalena Valley basin, which have been characterized by having the main hydrocarbon producing rocks of the petroleum system.

    With the data obtained from Microthermometry, the homogenization temperature and salinity values were estimated, and histograms of homogenization temperature frequencies were made. The salinity vs. homogenization temperature graphs show that the fluid inclusions found in the different samples analyzed have salinities that vary from 19.20% a 20.47% eq. in NaCl weight, similar densities found in the 0.93 a 1.06 g/cc intervals and homogenization temperatures between 120.0°C y 180°C.

    The homogenization temperatures obtained indicate that at the time of trapping, the rock was in the medium-light hydrocarbon generation window, which with subsequent diagenetic processes reached the current hydrocarbon characteristics of the Hondita and Loma Gorda formations, as evidenced in many oil fields in the Upper Magdalena Valley area.