THE ROCK COMPRESSIBILITY CHARACTERISTICS OF SOME INDONESIAN RESERVOIR LIMESTONES

Abstract

Rock compressibility is an important formation rock properties. It infl uences various processes
in reservoir and rock formations that encompass from sources of reservoir driving energy, changes in
other reservoir properties, to land subsidence. Various studies have been performed and published, but
no comprehensive studies have ever been performed on Indonesian reservoir rocks. This article presents
results of such studies on Indonesian limestones, reservoir rocks that have contributed much to Indonesia’s
national oil and gas production for decades. The study was carried out in order to study the characteristics of
limestone in its relation to rock porosity. A set of 84 limestone samples taken from fi ve productive formations
in Indonesia is used in the study. Some existing and widely known mathematical correlations/models are also
used to assist the study. Some of the results show that the existing models are not always valid for some of
the rocks, and therefore a new model is proposed for medium-hard and vuggy limestones. The results also
show that limestone characteristics are not related to rock types and place of origin, but instead to rock
hardness and degree of vuggy pore presence.