Research On Biological Method Crude Oil Recovery And Harmless Treatment Technology Of Oily Sludge In Oil Field

Oilfield sludge will generate oily sludge in the process of oil extraction,oil transportation,and oil refinery processing.If oily sludge is left untreated or not properly treated,it will not only pollute the environment but also waste oil resources.Oily sludge has been included in the list of hazardous wastes in China,and the residual sludge oily rate of oily sludge must be less than 2%before it can be discharged.The main purpose of this research is to treat medium and high oil content sludge by washing with surfactants to realize the resource treatment of oily sludge;biological sludge is used to treat low oil content sludge to achieve harmless treatment of oily sludge.Firstly,the electron microscope,X-ray diffractometer,energy spectrometer and other instruments were used to analyze the properties of oily sludge.It was found that the ease of sludge treatment has a certain relationship with the properties of oily sludge.The size of the voids and the composition of the minerals on the clay particles in the sludge are one of the main reasons for the difficulty in handling the sludge.By examining the technological parameters of oily sludge in the treatment of several biosurfactants,one of the several biosurfactants was screened for the best treatment effect.It can be known from the experimental results that the treatment effect of the Z-1 type biosurfactant is the best,and the final oil content of the residual sludge is 1.98%.Then,Z-1 was used to treat oily sludges with different oil contents to verify whether Z-1 was suitable for various oily sludges.The results showed that the high oil content sludges of Z-1 were not suitable for low oil content sludges.In order to realize the harmlessness of medium and high oil content sludge and reduce the oil content of low oil content sludge,these sludges are treated by a biological slurry reactor.The optimal conditions of petroleum hydrocarbon degrading bacteria and their conditions were found out by examining the conditions of oil hydrocarbon degrading bacteria degrading sludge.The experimental results show that the optimal condition is that the ratio of R1 bacteria in the bacterial solution is 1%(V _bacteria/V_{culture system}),and the temperature of 50°C,the dry oil content of the residual sludge is reduced from 19.41%to 0.92%,and The harmlessness of sludge.