The American Petroleum Institute estimates that oil and gas exploration and production in the US generates approximately 20 billion bbl of produced water annually. And, because the production life of wells is usually advanced, the ratio of barrels of produced water to hydrocarbons recovered can be as high as 9:1.
Accordingly, in the past several decades, produced water has become the largest byproduct in the oil and gas industry. Managing all this produced water includes injecting the water into the formation to maintain formation pressure, thereby increasing hydrocarbon production, or disposing of the water in deep wells. Before the water can be injected, disposed of, or discharged offshore, it is necessary to remove oil, suspended solids, or both to protect formation rheology or to meet discharge regulations.
If you ask an experienced produced water process engineer working in the oil and gas industry—they are getting harder to find these days—how to treat produced water, be prepared to answer a lot of questions. And, these are likely to be on a range of topics such as local operating conditions, characteristics of the produced water, water treatment requirements, and available treating options. It is also important to understand that produced water contains chemical characteristics of the formation and its associated hydrocarbons. Plus, the properties of produced water and its volume vary considerably depending on the location of the field, its geologic formation, the type of hydrocarbon product being produced, and the reservoir’s age.
For those new to produced water, the preceding information can be overwhelming. But for produced water experts, it is the basis for developing an effective and efficient produced water treatment strategy.
While an initial analysis could begin with a number of variables, contaminants in the water and the water quality requirements determine the treatment process. Contaminants are generally categorized into three types: suspended oil droplets/particles, dissolved organics and inorganics, and biological matter.
Treating Produced Water With Understanding
Daniel Shannon, Produced Water Product Manager, Cameron
26 November 2015