MITIGATION OF CALCIUM CARBONATE INORGANIC SCALING

Inorganic scale is a very common problem in the oil and gas industry.
Common types of scale include calcium carbonate, magnesium carbonate, calcium
sulphate, barium sulphate, strontium sulphate and radium sulphate. Carbonate
deposits depend on changing operational conditions such as pressure and temperature
whereas sulphate scale deposits depend on mixing incompatible waters and seawater
rich in sulphate. The focus of this project will be on calcium carbonate scale which is
one of the most common types of scale. Unresolved calcium carbonate scale problem
may lead to loss in production and damage to equipments which will eventually lead
to severe economic loss. In order to tackle the scale problem, scale inhibitors are
introduced into wells. Example of conventional scale inhibitors which is widely used
is diethylenetriaminepentakis (methylenephosphonica acid) or DTPMP. The
problems with conventional scale inhibitors are most of them are harmful towards
the environment. This project will look into green alternatives for calcium carbonate
scale inhibitors. The green alternatives consist of gambir extracts, aloe vera gels and
green tea extracts. Laboratory tests will be performed to evaluate their potential in
inhibiting the formation of calcium carbonate deposits. Comparisons in terms of their
effectiveness in delaying the deposition of calcium carbonate will be made between
the three materials for calcium carbonate scale inhibitors.