Scale Control in Oil Wells
Litho-Bac™ is a proprietary combination of natural, facultative anaerobic biologicals and biochemicals used in oil well operations to inhibit scale formation. Litho-Bac™ has some corrosion inhibition properties. Scale formation is inhibited through Litho-Bac™’s metabolic by-products, including alcohols, ketones, organic acids, and biosurfactants. Litho-Bac™ also has a limited ability to disperse, dissolve, and prevent paraffin deposition.
Application of Litho-Bac™ protects the formation face, as well as the downhole and surface equipment for scale deposition by sequestering and chelating major cations, such as calcium, magnesium, and barium. Some by-products of metabolism, the ketones and organic acids, are chelating agents that can inhibit the scale crystallization process. This is accomplished by bonding with the cation and preventing it from bonding with the anion to form an insoluble scale. This is similar to the process by which chemical inhibitors work. Litho-Bac™ further protects equipment with biosurfactants that remove previously deposited solids, which cause under deposit corrosion.
Litho-Bac™ comes as a ready-to-use liquid formulation and can be introduced by batch or squeeze treatments. Batch treatments usually involve the product being applied to the annulus and flushed with clean lease or fresh water. For optimum performance, it is recommended that the well be shut in for one to three days after treatment, however this is not mandatory. Treatment begins with an inoculation to establish the bacterial population of the well system. Thereafter, at predetermined intervals, maintenance doses of Litho-Bac™ can be added to maintain the colony of bacteria.
Squeeze treatment applications are a function of fluid production, porosity, perforation interval, and desired depth of penetration. The well is shut in for three to seven days.
Handling and safety
Litho-Bac™ meets EPA requirements for release into the environment. Special clothing or equipment is not required for handling Litho- Bac™. Routine hygiene should be observed.