• Down hole colonization of the reservoir has a number of negative impacts. Slime-forming sessile bacteria can block pore throats and reduce the injectivity of water injection wells. Most damaging, however, is contamination with sulfate reducingbacteria (SRB) such as desulfovibrio. These bacteria metabolize the sulfate from surface injection waters into hydrogen sulfide gas. This acid gas level builds over time and causes enhanced corrosion, increased production costs (due to necessary H2S scavenging) and health and safety concerns. These bacteria are extremeophiles and are able to survive in the high salinity, high-pressure, elevated temperatures and moderate pH levels typical of many reservoirs. Once bacterial colonies are established, it is practically impossible to disinfect a reservoir. The only true method to control the down hole environment is to ensure adequate biocide use top side.

• Due to the toxicity of many biocides to both the environment and to those handling the products, regulatory restrictions on biocides and their use have become more stringent in recent years.The biocides offered by Navdeep are non-oxidizing surface-active organic types. They disrupt the typical function of the cell by their adsorption onto cell walls. Our biocides are less corrosive to production pipe work.

• Our biocides are Aldehyde type, Amine type and non aldehyde - non amine type particularly based on Bronopol, Isothiazoline, Quaternary ammonium compounds, Gluteraldehyde and Carbamates.

• Selecting the right biocide depends upon the target organisms to be treated, the regulatory approvals applicable and the type of treatment regime proposed. Many of the biocide chemistries mentioned become inactive once they reach the surface environment and are readily biodegraded to benign metabolic products.