| Oily sludge containing polymer is a complex brown-black viscous solid,mainly composed crude oil,water,mud sand and polymer,which contains a lot of toxic and harmful substances.It not only pollutes the environment,but also harms human health.Therefore,the reutilization of oily sludge is considered as one of the most promising methods.In this thesis,the main research sample was the oily sludge got from Shengli oilfield.The analysis and measurements of the basic properties including its composition,particle size,potential performance,and morphology were performed to establish the necessary experimental basis for subsequent work.Emulsifier agent,suspension agent,cross-linking agent and other factors were systematically investigated and optimized.The emulsion suspension system and the gel-type profile control system were developed with stable performance and excellent profile control effect.The specific research contents were as follows:1)The composition,particle size,Zeta potential and morphology of oily sludge were investigated.The results were as follows: the water content,oil content and solid content of the oily sludge sample were 30.92%,15.41% and 53.67%,respectively.The particle size was mainly distributed between 3.12 and 2100 ?m.The particle size distribution was dispersed and there were large particles,which could not be used for profile control directly.Therefore,it was necessary to conduct screening treatment in advance.The study of Zeta potential showed that Zeta potential was negative,indicating that oily sludge was negatively charged.The morphology showed that oily sludge mainly existed in the form of aggregates,which was not conducive to direct pumping for profile control.2)On the basis of the above experimental results,by studying the influence of emulsifier,suspending agent and oily sludge carrying capacity on the stability of the emulsifying suspension system,the optimal formulation of the emulsifying suspension system was optimized and selected as: emulsifier,sodium dodecyl benzene sulfonate,0.1%;suspending agent,polymer I,0.3%?0.5%;oily sludge,sieved through a standard 150 mesh screen,1%?20%.Under this condition,the suspension rate of the emulsified suspension system based on oily sludge was larger than 92% after being placed at room temperature for 48 h.3)Aluminium citrate cross-linking agent was prepared by using citric acid and aluminum chloride.The effects of reaction temperature,reaction time,molar ratio of reactants and p H value on the gel-forming performance of the system were investigated.The optimal synthesis conditions were determined as: n(aluminum chloride):n(citric acid)= 1.6:1,reaction temperature 80 ?,reaction time 3 h,p H value 7.The aluminum citrate and phenolic resin were selected as cross-linking agents,respectively.The effects of the amount of cross-linking agent,polymer concentration,and sludge carrying capacity on the gel-forming performance of the system were investigated.The optimized formulations of two gel profile control systems were as follows respectively:(1)0.4% suspending agent,1.4% aluminum citrate,8% oily sludge,0.2% thiourea.Under this condition,the gelation time of the gel profile control system was 28 h,gelling viscosity was 36628 m Pa·s;(2)0.4%suspending agent,1.2% phenolic resin,16% oily sludge,0.2% citric acid,0.2%thiourea.Under this condition,the gelation time of the gel profile control system was32 h,gelling viscosity was 49910 m Pa·s.The performance evaluations of the best formulations of the two gel-type profile control systems showed that the viscoelasticity,thermal stability and plugging performance of the phenolic gel profile control system were better than those of the lemon aluminum profile control system.Therefore,the phenolic gel profile control system should be used as the profile control system.The results of this thesis have important and practical application value for the effective treatment and resource reuse of oily sludge. |
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