Consequently, with no energy potential or sales value, is its separation, treatment and disposal important?
When reservoir fluids (gas/oil/water) are brought to the surface for separation and treatment the pressure is reduced and this sometimes results in the formation of insoluble scales. In simple terms the reduction in pressure allows soluble bicarbonates to be converted to the carbonate ion with the release of CO2 gas: 2HCO3− → CO32− + CO2↑ + H2O The carbonate ion combines with any calcium ions, for example, to form insoluble carbonate scales. Not only can this result in reduced flowrates (loss of revenue) but this can have an adverse effect on system integrity and needs to be addressed. Inhibition of scale formation can be achieved by dosing a scale inhibitor chemical to the reservoir fluids while these are still at high pressure. The first stage in the separation of the oil from the other constituents is most often a horizontal three-phase separator (Figure 2), sized so that the residence times of the oil and the water are maximised. Solids are sometimes produced along with the oil, ga
