Experimental Study On Deep Deoiling Of Platform Production Water By Fiber Coalescence Technology

With the exploitation of offshore gas field stepping into the medium-term,down-hole pressure,production and operating pressure dropping,and the gas flow rate increasing,the oil-in-water emulsion produced in the process of heat transfer and pipelines becoming more serious,a large number of small emulsified oil droplets with size smaller than 10?m coming into being,this part of the fine oil droplets are beyond the separation accuracy of the existing production water oil removal process,which is rely on hydrocyclone,it results in the excessive emission of discharged production water.With the increasingly strict marine environmental protection law and inspection,the transforming and upgrading of the existing production water oil removal process is imminent.Many problems exist in present treatment process,such as low efficiency,poor stability and large area occupation,needing dosing,etc.So the development of new highly efficient and compact technology and equipment for production water oil removal has great significance and broad market prospects.Considering the unique advantage of coalescence technology,this paper designed the modular separator based on fiber bed coalescence.The effect law of some significant factors such as operation conditions,the emulsion properties and fiber bed characteristics on the coalescence separation performance of fiber bed had been researched deeply by systematic experiments.The optimized fiber bed samples were designed and controlled operating conditions to estimate the adaptability of the modular separator for production water oil removal process on offshore platforms.The main results obtained are as follows:(1)Specific fiber bed characteristics corresponding to the specific critical flow velocity,within the critical flow velocity is efficacious workaround and the separation efficiency will drop quickly when exceeding the critical flow velocity.The separation efficiency increases with the increase of the specific surface area of fiber bed and the growth appears first quick back slow trend,but the growth trend of the pressure drop appears approximately exponentially with the increase of the surface area.The separation efficiency drop with the increase of the degree of emulsification,and the feed concentration had little effect on the separation efficiency under the constant degree of emulsification.(2)Under various operating conditions including production separator decompression,on-off of the production water booster pump and series connection with hydrocyclone and so on,optimized modular separator can keep the average outlet oil content stably less than 30mg/L,meeting the requirements of the production water oil removal on the platforms.