Extraction of oil from down hole poses many challenges and all the time oil does not naturally flow out from the Oil well. Lifting of Oil from the reservoir depends on several factors. In this blog, We try to outline the basics with out getting too much into the technical part . Any one need more specific technical detail may refer to relevant text books or even Goole for the information.
The fundamental behind extraction of oil from well lies in maintaining the pressure of the reservoir. Most widely used practice to maintain reservoir pressure is to inject water back into the reservoir from top side. Normally an excess amount of water is injected deep down into reservoir than the total amount of fluid (Oil + Gas + Water) extracted from the reservoir.
This process puts tremendous pressure on the fresh water resources in the surrounding area and creates a huge environmental impact.
In the extraction process, water is also back produced from the wells in larger quantities, typically in the range of 20%-80% based on the reservoir characteristics and age of the reservoir (period for which the wells in the location of the reservoir in question is in operation)
Water so produced from the extraction process is termed produced water. The produced water requires stringent treatment before discharge as it might contain harmful chemicals, mineral residues and microorganisms. Also, at toward the later half of the reservoir life, the quantity of produced water becomes huge. Not only the treatment and discharge cost becomes significant but also the challenges associated with meeting the discharge norms increases.
At this juncture, the idea of putting back the produced water back into the reservoir along with injection water comes handy and more attractive option. This idea when implemented, not only relieves the operator from the head ache of treating and discharging the produced water into surroundings , but also significantly reduced the load on fresh water resources that are exploited for obtaining the injection water.
The capital cost associated with setting up a produced water treatment plant for reinjection will be outweighed by the growing environmental and operational headaches. Many Oil and Gas operators have successfully moved to re-injection of produced water in recent years and this is more gaining importance in the coming days.
Aalosanai engineering services has people experienced in the implementation of produced water treatment and re-injection. Would you need any assistance in this area please do contact us.
