Many challenges are encountered when separating oil and water in a production train. Two of the most common challenges are the presence of stable emulsions and/or high oil viscosities - both of which can limit separation efficiency significantly if not appropriately addressed. Production of “unconventionals” such as heavy oils is becoming more the norm in today's mature oil industry, where most of the light and easy oil fields have been produced. Stable emulsions are increasingly encountered as new wells and fields are tied-in to existing infrastructure, which increases tendency to form stable emulsions due to incompatible chemical compositions. The conventional solution to these challenges includes a combination of high process temperature, higher chemical dosages, larger vessels and/or more separation stages. A significant drawback to conventional separation solutions is that they often demand increased energy consumption, higher material costs and operating costs, and/or large space for the production facility. Furthermore, it is not always feasible to address the issues by conventional means due to restricted energy availability or space restrictions. In the presentation we focus on how the challenges can be resolved more efficiently by application of electrocoalescence at an early stage in the process train. The concept of electrostatic separation has been taken one step further with a Vessel Internal Electrostatic Coalescer (VIEC) that tolerates water and gas contents up to 100%.
The VIEC technology was the OTC “Spotlight on new Technology” award winner in 2004 and has since then been implemented on several major projects.