FACTORS AFFECTING RESERVOIR AND FILTRATION PROPERTIES OF CARBONATE ROCKS OF THE MAIN DOLOMITE(THE POLISH LOWLAND)

摘要

Pore space parameters(mercury porosimetry) and fracture properties were investigated. Mercury porosimetry shows great space heterogeneity of pore space parameters as well as specific shapes of pore bodies and channels.This was verified by computer analysis of microscopic images.From fractal analysis we distinguished three fracture systems. Analyses of thin sections and polished sections gave estimations of filtration properties of all fracture systems. In addition reservoir geochemistry researches were done.Pirobitumines were identified in the pore space of the reservoirs rocks.Correlation between oils and source rocks showed migration paths of hydrocarbons and explained continuity of the analysed reservoir. The next part of our investigations focused on the influence of pirobitumines on wettability.Amott wettability tests were performed.A great part of the analysed rocks showed mixed wettability.Also fractures showed various types of wettability because of residual organic matter mixed with clay minerals lying on fracture surfaces.These results agree with relative permeability investigations which were done as a last part of laboratory investigations.Results of laboratory measurements were compared with well logs and normalized using field test permeability.