Dehydration Technology Study On Crude Oil From Polymer Flooding Of Salt-overlying Oilfield

There being characteristics of shallow embedding, excellent development and high viscosity in the salt reservoir of Kenneyak oilfield. By more than forty year's development, the reservoir heterogeneity is more serious , composite water cut is 76% and recovery percent of reserves is 13%,the daily average production rate of a well is less than 2t. As a result, it is imperative to improve the effect of oilfield development.The new technology of polymer flooding has been widely used in Daqing Oilfield in China, and has made very clear technical economical effect, it can effectively solve the contradictions of heterogeneous reservoir, reduce oil-water mobility ratio, increase the reservoir sweep volume and improve the development effect of the water drive oilfield. As a new technology of effective development of the Kenneyak oilfield salt reservoir, the experimental study of Polymer Flooding Technology is now in full swing.As one of the important parts of Matching Technology for polymer flooding, treatment technology for crude oil from polymer flooding is the key factor to guarantee the successful implementation of polymer flooding surface engineering. The polymer flooding produced liquid contains the displacing polymer, it inevitably increases the viscosity of the produced liquid, changes the nature of the emulsion, and increases the stability of oil-water emulsion, and this certainly will bring a series of effect to the surface treatment technology of produced liquid. Daqing Oilfield has engaged in research and practical experience of polymer flooding produced fluid treatment for many years, but the nature of the Kenneyak salt reservoir is different from the Daqing Oilfield, and the disposal difficulty is high. Therefore, with the combination of polymer flooding pilot test, it is very necessary to carry out the research on treatment technology for crude oil from polymer flooding in the salt reservoir of Kenneyak oilfield.The research purpose of this thesis is to use the research methods, means and results of treatment technology for crude oil from polymer flooding of Daqing oilfield for experience, base on the properties of the produced liquid and environmental condition of polymer flooding experimental area in the salt reservoir of Kenneyak oilfield and the principle of the combination of laboratory test and field test, and then to identify the technical way suitable for treatment of crude oil from polymer flooding of Kenneyak oilfield.By experiment the crude oil dehydration demulsifier suitable for the produced liquid of polymer flooded reservoirs of Kenneyak oilfield was attained and the technological parameters of the dehydration of polymer flooding produced fluid in the test area was determined. Under the conditions of dehydration temperature of 35℃, the sedimentation time of 60 minutes, oil percentage in water less than 20%, oil content in sewage lower than 2000mg/L and meet the subsequent requirements of dehydration,the demulsification efficiency of demulsifier DP-8 was better than that of demulsifier KLN-1 for the thermochemical settling dehydration of produced liquid. For the well of higher chemical agent content, when the temperature is 65℃, in order to achieve the technolgy of water content in oil lower than 0.5%, the addition dosage is 1000mg/L and the sedimentation time is 4 hours.