Abstract

WATER THAT comes to the surface in oil- producing wells is usually referred to as produced, or effluent water. Oil companies often reinject that water back into oil reservoirs for reservoir-pressure maintenance, a technique called produced-water reinjection (PWRI). Alternatively, it may be discharged into the sea, rivers, or lakes, or into underground zones or aquifers at shallower depths than the source-oil reservoirs, know as disposal wells. In the upstream industry, water is also used for:

• Desalting crude oil – washing salt or highly saline water out of oil using fresh, or low-salinity water, often obtained from a shallow aquifer;
• Water injection for reservoir-pressure maintenance, using sea, shallow-aquifer, or river water before implementing PWRI;
• Process cooling, using sea, shallow-aquifer, or river water;
• Process water – for wash-down, making up chemical solutions, such as drilling fluids; and
• Potable water, suitable for drinking – for drilling rigs, construction camps, offices and accommodation, perhaps from shallow aquifers, rivers or desalination of seawater or saline aquifers.

Water is also used in great quantities in downstream oil processing, creating large amounts of slightly contaminated wastewater, at many intermediate stages in pipeline hydro-testing and, among other uses, as tanker ballast waters.



Publication:    Petroleum Economist – Fundamentals of Oil and Gas in the Middle East

Location:    ADIPEC, Abu Dhabi, UAE    

Authors:    K.Robinson

Date:    November 2008