Produced water is the largest-volume waste stream in oil and gas production, with an estimated 240 mmbod produced globally. Water cut is forecast to increase rapidly in key oil and gas areas, steadily increasing water-handling costs.

The EPCON* Compact Flotation Unit (CFU) is a reliable and highly efficient technology for separating water, oil and gas to achieve a high standard of treated water. It requires no external energy and the CFU also has a smaller volume and shorter retention time than traditional flotation units currently in use.

Depending on local regulations, water from the CFU process can be discharged with little or no additional treatment.

EPCON CFU Overview

Since 1999, CFU technology has been under development and in joint testing with oil companies operating in the North Sea. Today, it is a well-proven environmental solution to treat the increasing volumes of produced water. Major operators worldwide have tested and/or installed the EPCON CFU technology.

The EPCON Compact Flotation Unit (CFU) is a reliable and highly efficient technology for separating water, oil and gas to achieve a high standard of treated water. It requires no external energy and the CFU also has a smaller volume and shorter retention time than traditional flotation units currently in use.

How it works

Several combined processes, including gas flotation and induced centrifugal inertia forces, act on the fluid components of different specific gravities. The small oil droplets are made to agglomerate and coalesce, facilitating separation from the water. The separation process is aided by internal devices in the chamber and a gas flotation effect caused by the release of residual gas from the water. Process optimization can also be achieved by the introduction of external gas and/or flocculants. The separated oil and gas is removed in a continual process via an outlet pipe at the top of the vessel.

Compared to traditional separation techniques, the CFU delivers higher capacity and better performance at a lower cost. The single-step separation has been proven to reduce the Oil-in-Water (OiW) content to below 20 ppm (20 mg/L), while simultaneously degassing the water. Two CFUs in series have been proven to reduce the OiW content to below 10 ppm (10 mg/L). The process requires a retention time of less than 30 sec to perform effectively. A vessel with an operation volume of only 70.6 ft3 (2 m3) can treat awater flow up to 8,829 ft3 (250m3/hr). The EPCON CFU from M-I SWACO is carefully engineered to interface with other offshore production installations. The technology can be designed to fit all pipes and can easily be adapted to local conditions and requirements.