DESCRIPTION OF NIMR REED BED PROJECT, NIMR, OMAN. PETROLEUM DEVELOPMENT OMAN (PDO).

DESCRIPTION OF NIMR REED BED PROJECT, NIMR, OMAN. PETROLEUM DEVELOPMENT OMAN (PDO).

BACKGROUND The Nimr Reed Bed Project, in Oman, is a project developed by PDO, Oman, OIT (Oceans Integrated Technologies ), United Kingdom and TransForm Danish Rootzone, Denmark. PDO, at their location in Nimr, currently produce oil at about 30.000 m3 per day. There are plans however, to significantly increase production within the next 3 years. The oil in this area of Oman, has a very high content of water that causes problems in processing and water disposal. At the present time the volume of water after oil separation is in the region of 170.000 m3 per day. This water is highly salin, and also contains traces of oil and heavy metals, among other materials. Today, the wastewater is re-injected into the original reservoirs, by high-pressure injection. An expensive and energy intensive procedure. For the past couple of years PDO have been running a small-scale reed bed pilot plant at the Rahab Farm, close to Nimr. This process has been used to evaluate reed bed efficiency, and also to find crops that can resist salinity, and could therefore be irrigated with the treated water from the reed bed. The project has achieved very interesting results. The Reed Beds has proved itself to be capable of efficiently, and cost effectively, handling the treatment of oil, heavy metals and other contaminants in the oil production wastewater. The problem in Nimr, is the high salinity of the water. With Reed Beds, as well as any conventional treatment system, reduction of salinity cannot be assured. However, reduction up to 40 50 %, has been achieved in other Reed Bed projects and it is hoped to apply this at Nimr. 2

CONCEPT PDO took the decision to make a large scale pilot project for the process water, at Nimr. The system currently under construction consists of 8.000 m2 Reed Beds, and 24.000 m2 of planted evapotranspiration ponds. The system will treat, initially, 3.000 m3 per day of water from the oil separation process. It is hoped that using the pilot project we will develop an effective and environmentally sustainable method of treatment of the contaminated water from the production site. To reduce the high costs of re-injecting the separated water, it is planned to find a way how the treated water can be recycled, and concurrently be used for some agriculture that can bring benefits to the country and it s population. The first step will be to assure a high evapotranspiration rate within the treatment system to reduce the big water volumes. However, this process will also mean that the salt concentration in the water will be increased. Therefor it is very important to find seeds / plants, that are able to resist a high salinity, and still be able to grow and produce a sufficient harvest. 3

The experimental resource will mainly be used to find crops that are scarce in the country, or can be harvested for exportation such as, for example, rice or other basic crops. A number of plants have already been selected that seem to be suitable for this purpose, and those will initially be investigated and evaluated within the project. Some alternative plants will also be investigated, that can be used to provide green areas in the desert. Other alternatives, for the re-use of the treated water will also be examined and evaluated, to examine all the possibilities for reusing or recycling the countries precious water resources. The pilot project, is expected to be in full operation at the end of March 2.000. For further information feel free to contact us at e-mail: rootzone@image.dk, or PDO directly by e-mail: roger.jha.walpot@pdo.co.om. 4

The project is built up, in two equal parallel lines. A-Train and B-Train. Each Train, consists of four beds in serie. B-Train is in operation, with process water since a while back and here we show some results from the process. Oil in Water: (Average) Aw = Inlet: Cw1 = Outlet bed B1: Cw2 = Outlet bed B2: Cw3 = Outlet bed B3: Cw4 = Outlet bed B4: 137,00 ppm 2,75 ppm 1,70 ppm 1,80 ppm 2,30 ppm Oil in water Oil in Water trend B-Train, August 2000 1000 Oil in water ppm 100 10 1 0,1 Aw Cw1 Cw2 Cw3 Cw4 05-aug-00 12-aug-00 19-aug-00 26-aug-00 5

Salinity: (Average) SalAw = Inlet: SalB1 = Outlet bed B1: SalB2 = Outlet bed B2: SalB3 = Outlet bed B3: SalB4 = Outlet bed B4: 6180 ppm 7310 ppm 9600 ppm 11800 ppm 13130 ppm Salinity Salinity trend Train-B, August-2000 Salinity x 1000ppm 15 14 13 12 11 10 9 8 7 6 5 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 SalAw SalB1 SalB2 SalB3 SalB4 6

Flow: (Average) Inlet B-Train: 540 m3/day Inlet A-Train: 133 m3/day Reed-bed System Flow Reed-bed System Flow trend Train-A&B, August- 2000 700 600 Flow in m3/d 500 400 300 200 100 0 48FIR121 VfA 7