At the moment technologies used in the treatment of offshore produced water of oil and gas platforms are mainly aimed at the removal of dispersed hydrocarbons (dispersed oil). The focus on the removal of dispersed hydrocarbons is due to current legislation worldwide aiming at the reduction of dispersed oil emission. In this paper a survey is presented of the development of legislation for offshore produced water emissions within the North Sea area and its effect in other areas worldwide as well as the resulting developments in other new technologies. It was primarily the Norwegian oil & gas industry that has initiated this shift by introducing the Environmental Impact Factor. This has led to the identification of specific constituents of the produced water that contributes to the EIF. These are mainly Polyaromatic Hydrocarbons (PAHs), Aromatics (BTEX) and Alkylphenols. This conclusion has been recently supported by Shell Philippines. In this paper the effect of new extraction based technologies like the Macro Porous Polymer Extraction (MPPE) technology on the reduction of the EIF and the specific toxic constituents are described. A real life case is presented where at still the same Total Organic Carbon Levels (TOC) the toxic content had increased significantly with disastrous effect on biocultures. It is explained that as a consequence integral parameters like BOD, COD, TOC are of no value in identifying the toxic content of the produced waterstream. The MPPE technology is described, industrial applications show a > 99% reduction of the toxic content, i.e. PAHs, BTEX and aliphatics, in oil and gas / condensate produced waterstreams. Finally conclusions are presented regarding trends in legislation, fundamental technological mechanisms that are required and approaches to treat produced water to meet future legislation.
The removal of toxic dissolved and dispersed hydrocarbons from oil and gas produced water with the Macro Porous Polymer Extraction Technology