Study Of Chemical Agent For ASP Flooding Produced Oil-bearing Water In Xingerzhong Pilot Area Of Daqing Oilfield

In the 1980s, Alkali/Surfactant/Polymer(ASP) flooding whichappeared as a new method for the tertiary recovery efficiency in thelater period of water flooding. Although we began the research onASP comparatively late, the technique developed rapidly in theseyears.After dozens of years of laboratory study and pilot test, 5 ASPflooding pilot tests have been successfully performed in DaqingOilfield from 1993 to 1997. The experiment result shows the ASPflooding can increase recovery 20% more than water flooding.However, the application of ASP flooding is limited to someextent because of technical difficulties of oil-bearing water treatmentin oilfields.Because there are residual alkali, surfactant and polymer in ASPflooding produced oil-bearing water in Xingerzhong pilot area ofDaqing oilfield, the difficulties, most of which arose from oil contentand viscosity of water-phase, granules in crude oil and surfactantstrengthen emulsification etc., present in oil-bearing water treatmentlead to poor oil/water separation.The influence of residual alkali, surfactant and polymer on thestability of ASP flooding produced oil-bearing water is studied onartificial ASP flooding produced oil-bearing water.Considered mainly with nonionic and anionic active components,a formula,which is the best effective in oil-bearing water treatment,has been developed for ASP flooding waste water treatment. Theformula is selected from 11 formulas that are composed of 4 chemicalagents through making multivariate preparation. The 4 chemicalagents which are selected from 45 nonionic and anionic chemicalagents are effective in treatment of oilfield produced water. Theformula is named after M-10 Formula Agent because it is the 10th of11 formulas.M-10 Formula Agent is suitable for treating ASP floodingproduced oil-bearing Water in Xingerzhong pilot area of Daqingoilfield. If M-10 Formula Agent that a dosage is smaller than20mg·L-1 is cast into the produced liquid, the water which doesn'tflow into the filter after being treated by a thermo-chemical settlingand flotation process will reach the study goal that the oil content ofoil-bearing water is smaller than 50mg·L-1.Both lab experiments and field applications show that M-10Formula Agent has efficient capability of oil-bearing water disposal.With a dosage of 13.5mg·L-1 in the produced liquid, M-10 FormulaAgent reduced the average oil content of the wastewater ofXingerzhong pilot area from 105.5mg·L-1 to 50mg·L-1 before thewastewater flow into the filter.Lastly, the paper points out the oil content of the oil-bearingwater of Xingerzhong pilot area will be treated to reach the studygoal(<50mg·L-1) without the existent two stage settling in oily watertreatment process if a dosage that M-10 Formula Agent is cast into theproduced liquid is smaller than 20mg·L-1.