Numerical analysis of flow field and separation characteristics in an oilfield sewage separation device

A novel oilfield high-oil-recovery water injection treatment device, the hydrocyclone oil removal device, was developed to treat oilfield sewage in the oil phase. It addresses the problems of high oil content in oilfield sewage, direct discharge of contaminants to the environment, and reduction of formation water absorption capacity by reinjection formation. An experimental verification and numerical simulation of the device were carried out to analyze its mechanism and influencing factors. An analysis of the flow path, phase distribution, velocity distribution, and pressure distribution of oil and water revealed the oil removal mechanism of the hydrocyclone oil removal device: automatic separation of oil and water could be realized by using the physical properties of the fluid, the special structure of the equipment, and the appropriate operating parameters. The influence of the inlet oil concentration, flow, pressure, and oil droplet size on the separation efficiency was investigated. The inlet flow, pressure, and the oil dro-plet size were found to be directly proportional to the separation efficiency, and the oil concentration was found to be inversely proportional to the separation efficiency. These results could further the efficient application of the high-oil-recovery water injection treatment device. The research results also have important engineering value for the efficient treatment and recycling of oil and gas field wastewater. (c) 2021 Published by Elsevier B.V. on behalf of The Society of Powder Technology Japan. All rights reserved.

Automated summary

The novel oilfield high-oil-recovery water injection treatment device, utilizing a hydrocyclone oil removal device, effectively addresses issues such as high oil content and environmental pollution in oilfield sewage, and plays a significant role in improving oil-water separation efficiency.