The Study Of Dehydration Equipment For ASP-Flood Produced Liquids

The technology of ASP flooding has been studied as an important measure to keepDaqing Oilfield developed steadily from the early 1990s. Chemical agents in ASP-floodproduced liquids have great effects on conventional equipments of treating produced liquids,which has been found in lease tests on ASP flooding during the Ninth Five-Year Plan period.As for Free Water Knockouts (FWKOs), the effects are follows: the properties of producedliquids have changed greatly with partial production of chemical agents (alkaline, surfactantand polymer), which causing the separation of oil and water more difficult. What's more, because of ASP-flood produced liquids carrying more impurities, more sediment can beproduced in FWKOs, causing a decrease in operational efficiency of treating equipments. Asfor electric dehydrators, the effects are follows: operation of equipments unstable, greatincrease in not only water content of oil but also oil content of water after electric dehydration,a decrease in treating capacity and great increase in power consumption.The technology of ASP flooding is going to be applied on a large scale in DaqingOilfield during and after the eleventh Five-Year Plan period. In order to treat produced fieldsefficiently, equipments need developed accordingly in order to meet the needs ofindustrialized dissemination.On the basis of lease tests on ASP flooding carrying out in Daqing Oilfield, equipmentsof free water dehydration and electric dehydration for ASP-flood produced liquids, such asFWKO, control cabinet of electric dehydration, transformer and electric dehydrator, havebeen developed. Prime targets are follows: in the condition of treatment temperature not morethan 45℃,retention time not more than 30min, and the dosage of demulsifier not more than30ppm, FWKOs can achieve the efficient treatment of ASP-flood produced liquids. Namely,after treatment water content of oil is not more than 30%, and oil content of water is not morethan 3000ppm. For electric dehydrators, in the condition of water cut of inflowing liquids notmore than 30% and treatment temperature not more than 55℃, after treatment water contentof oil is not more than 0.3% and oil content of water is not more than 3000ppm. By using combination of independent development and digestion, on the basis oflaboratory and lease tests, FWKOs have been developed, and the structure of FWKOs hasbeen optimized, and control system of oil-water interface has been improved. Furthermore,control cabinet of electric dehydration, transformer and electric dehydrator have beendeveloped, which three have been combined so that stability and utilization rate of completeequipments can increase, and dehydration temperature, the dosage of dumulsifier and powerconsumption can decrease, and dehydration effectiveness can be ensured.