Pore systems evolution in the karstified Albian Mfamosing Limestone, Calabar Flank southeastern Nigeria. – A.A. Aderogba
Pores are all openings found in a rock. Some rocks have simple while others have complex pore systems. Most sandstone reservoirs are typically single-porosity systems of relatively homogeneous in nature. Carbonate reservoirs commonly have multiple-porosity systems. They are often complex and heterogeneous nature. Today, one of the most pressing problems of petroleum production from limestone reservoirs has been that of predicting the nature and origin of porosity of carbonate rocks. If these conditions could be better understood, then more producing horizons could be demarcated and exploited. Because, the specific types, relative abundances of pores present, and their distribution within the reservoir, impart petrophysical heterogeneity to the reservoir, an extraordinary knowledge of porosity is necessary. This work, therefore, demonstrates how karstic, meteoric and burial dissolution processes affect the distribution of porosity in limestone reservoirs with examples from the Mfamosing Limestone. In this study, attempt is made to explain the processes by which most types of openings in limestone may be created.