SHORT PERIOD OF STUDY ON THE POREWALL STABILITY OF CARBONATE ROCK IN PERAK

There is a gap of knowledge on the dissolution kinetics of carbonaterocks
originating from Malaysia This information is critical for C02 sequestration and EOR
endeavours. Samples of carbonate rocks were taken from SimpangPulai and Sungai Siput
area of Perak, Malaysia. Theobjective of this study was to evaluate the kinetics of dissolution
of these carbonate rocks using two types of acids namely hydrochloric and acetic acid. These
acids represent inorganic and organic acids respectively.
Low concentration of O.OlM was used to simulate [H+]concentrations in
C02 sequestration situations. The low concentration ofacid also enables us to better
understand the dissolution rates of thecarbonate rocks. The experiments were done at room
temperature. Thisapproach also enables us to better understand the change in the strengthof
the carbonate rock after acid dissolution. Porosity and permeabilitychanges were recorded
intermittently. The preliminary results show thatdissolution kinetics is dependent on the
resident fabric of the rock andthe type of complexation ions present. Re-precipitation of
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' carbouateminerals was not observed during ~e experiments.