The invention belongs to the technical field of
oil field gathering and transportation systems, and particularly relates to a combined
crude oil dehydration and
desalination treatment device which comprises a shell, a pretreatment chamber is arranged at one end in the shell, an ultrasonic demulsification chamber is arranged on one side of the pretreatment chamber, and an electric
dehydration settling chamber is arranged on one side of the ultrasonic demulsification chamber. Through the combined design of ultrasonic
waves and an
electric field, the efficiency and adaptability of
crude oil dehydration and
desalination are improved, oil-in-water and water-in-oil particles can be effectively opened through the mechanical oscillation effect generated by the
ultrasonic generator in the ultrasonic demulsification chamber, free-state oil drops and water drops are formed, and the oil-in-water and water-in-oil particles can be effectively removed. An alternating-
current electric field and a direct-
current electric field which are respectively formed by the grid plate and the vertical
electrode plate can be used for coalescing and
settling water drops in oil under the actions of
dipole coalescence, oscillation coalescence,
electrophoresis coalescence and the like, and due to the synergistic action of the double electric fields, the quality of the dehydrated
crude oil is improved, the
volume fraction of water in the crude oil is reduced, the
power consumption is reduced, and the stability of the electric fields is enhanced.