Oil Water Treatment Technology

When oil companies drill a well, approximately 130,000 gallons of water are required. This quantity is dwarfed when during well stimulation, water usage increases to 2.5 million gallons. During production, water injection or flooding increases the well pressure and enhances oil recovery from 30% of the oil in place to as much as 50%. The water used during these operations is required to be of a certain quality, however the importance of proper water treatment is often underestimated. This is due to the tremendous variation in the water sources used i.e. seawater, borehole, and river water. Poor water quality may lead to clogging of the reservoir and loss of oil production particularly during well stimulation and water injection.

For every barrel of crude produced 7-10 barrels of water are produced, reusing it is vital for reducing the quantity of water used during the reservoir’s lifetime. Produced water contains some oil and its treatment to an environmentally acceptable level is mandatory before disposal. Good oil and water separation is therefore necessary and the physics as well as the mechanics of proper oil and water separation need to be well understood not only for water reuse but also to meet these strict environmental discharge regulations. The methods most commonly employed for oil water separations, include gravity settling and gas flotation. Flotation depends on the surface characteristics of the oil and on its interaction with the gas bubbles. The method used depends on many factors including the type and physical and chemical characteristics of the crude oil ultimately however the governing principle of these separations is dictated by Stokes law.