Application Spotlight: Injection Wells

Injection wells and drilling can be a quite confusing subject for those who are unfamiliar with oilfield operations. This short application spotlight is intended to provide readers with a brief overview of the terminology and processes associated with this subject.

Oilfield operations commonly utilize two types of injection wells. Water floods, which are used as an option for Enhanced Oil Recovery (EOR) from a producing well and Salt Water Disposal (SWD) wells used to dispose of flowback and produced waters. 

While both EOR and SWD injection wells can be operated without treating the water before injection, optimal well performance can only be achieved if the water is properly treated and conditioned before it has been injected downhole.

Pre-injection treatment can involve a variety of steps, but commonly involves the separation of hydrocarbons from water; the removal of hydrogen sulfide and scale-forming components from the water; adding a biocide to control oilfield bacteria, and filtration to remove suspended solids. 

When these treatments are utilized before water is introduced into an injection well, operators will experience improved injectability through the removal of formation plugging solids and bacteria, the diminished souring of the wells and diminished scale formation.

While many technologies and chemicals can be used to treat water before injection, sodium hypochlorite produced by a De Nora ClorTec electrochlorination systems can safely facilitate the overall treatment process at an extremely low-per-barrel price.

As an antimicrobial agent, sodium hypochlorite can eliminate common oilfield bacteria such as Sulfate Reducing Bacteria (SRBs), Acid Producing Bacteria (APBs), and Iron Reducing Bacteria (IRBs).

When these bacteria are allowed to proliferate, they can damage equipment through microbially induced corrosion, plug the formation through downhole biofilm formation; sour the formation and decrease the value of hydrocarbon products.

Beyond eliminating oilfield bacteria, sodium hypochlorite is also a broadly effective chemical oxidant that can directly eliminate hydrogen sulfide and ammonia as well as oxidize reduced iron and iron sulfide. It can also facilitate the removal of suspended solids through iron oxidation-driven coagulation/flocculation processes. These treatment steps can minimize workplace hazards and further improve well injectability through the removal of solids that can block formation porosity.

Overall, De Nora ClorTec electrochlorination systems deliver the safest oilfield oxidizing chemistry at the lowest per barrel price available. Contact De Nora today to see how we can help with your injection-well water treatment challenges.