Research on treatment of Oilfield Produced Water

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The Petroleum and Chemical Engineering Department (PCED) in the College of Engineering at Sultan Qaboos UniversitySultan Qaboos University is going on with the research project on treatment and utilisation of oil field produced water in the Sultanate, the first phase of which was taken up way back in 1996, that time in collaboration with Japan Petroleum Energy Centre (JPEC). The present project titled "Treatment and Utilisation of Oilfield Produced Water in Oman", undertaken in collaboration with Japan Co-operation Centre Petroleum (JCCP), is scheduled to be completed in 2010.

Asked about the significance of the study, Dr Rashid al Maamari, an associate professor in PCED at SQUSQU, who is involved in the ongoing project, said: "Oilfield produced water is oily wastewater that is associated with oil production. Depending on the field, the quantities of produced water can actually be several times the quantities of oil being produced. While in some oilfields this water is reused in the oil production process, in other fields this water is disposed of. For instance, in a single southern oil field in the Sultanate, roughly a quarter million cubic metres of water per day is produced and disposed of. This quantity exceeds the daily water distribution in the whole Muscat Governorate".

Dr Rashid Maamari added that while disposal of such oily water to shallow aquifers risks contamination of valuable ground water supplies, disposal to deeper aquifers is expensive due to the great amount of energy required to do so. "If such produced water can be properly treated at reasonable cost, great quantities of waste water can be converted into a valuable water resource, particularly important for an arid climate region like Oman," he added. Treatment of oilfield produced water is particularly challenging due to the small size of oil droplets in the water and relatively small difference in densities between the water and the oil; quantities which make treatment by conventional oil industry gravity separation methods is difficult.

During the first project taken up in 1996, an effective air flotation, filtration and adsorption process was developed to treat this water. A pilot plant of three tonnes per day capacity was fabricated and developed at the university, with treated water being utilised for irrigation of three types of forage crops: Rhodes grass, barley and alfalfa. This project was initiated by Dr Mohammed Hamed al Rumhy, Minister of Oil and Gas. The present project initiated by Dr Rashid al Maamari seeks to build on the work of previous studies.

The ongoing research includes investigation of lower cost technologies, including development of locally produced adsorbent materials as well as further examination on ways to utilise treated water. Another PCED-Japan joint study was initiated by Dr Ali Saud al Bimani, present Vice Chancellor of SQUSQU in 1999 and titled "Evaluation and remediation of ground water contaminated groundwater in Oman". The study was sponsored by JCCP, and treatment of an actual contaminated site continues till date.

© Oman Daily Observer 2008