Hydrogen Sulphide (H2S) is a colourless gas that smells like rotten eggs (from the sulphur). Often referred to as "sewer gas," hydrogen sulphide is highly poisonous as well as corrosive. Small concentrations in air may be fatal in minutes. Hydrogen sulphide can be found as a component of formation gases, dissolved in water, hydrocarbons, or even liquid sulphur (King, 1974). Thermal degradation of organic materials and sulphate reducing bacteria (SRB) can create hydrogen sulphide along with other gases. Although hydrogen sulphide can have adverse effects on viscosity, fluid loss, and fluid chemistry.