Pore-wall Stability in some Carbonates from Sarawak

Carbonates are a class of sedimentary rocks composed primarily of
carbonate minerals. The two major types are limestone, which is composed
of calcite or aragonite and dolostone, which is composed of the mineral dolomite. There
is still a lack of knowledge in the behavior of limestone found in Malaysia to acidification
technology. This study is conducted in order to understand the performance of the rock
so that we can enhance the production of oil as well as enhance C02 sequestration.
Therefore, the objective of this study is to identify the effects of organic and inorganic
acids on the dissolution kinetics of selected carbonates. Pore-wall stability is affected by
the fabric of the rock and various geochemical conditions such as mineralogy,
composition, solids content, rheology, filtrate and its mineral compositions. External
acidizing experiments was conducted in order to understand the behavior and
performance of the core samples. From this experiment, the result shows that kinetics
dissolution for both samples are higher when immersed in inorganic acid compared to
organic acid. This is mainly because inorganic acid have higher value of acid
dissociation constant (pKa) compared to organic acid.
This project also won a bronze medal in the 281
h Science and Engineering
Design Exhibition (SEDEX) competition held at UTP on August 10-11, 2011.