Floating production facilities are very sensitive to equipment weight and footprint. New electrostatic technologies have enhanced the dehydration and desalting processes for crude oil by increasing the electrostatic field strength of the treaters and improving treater hydraulics, allowing the use of compact and lighter equipment with a larger operating window.
Topsides processes on offshore platforms include a series of process vessels for oil / water / gas separation, with separate polishing processes for the separated gas and produced water phases. The wider the operating window and the higher the process efficiency for each process step, the fewer number of process steps is required and the more compact the separation train.
This paper describes a 2-pronge approach for the crude oil dehydration process, providing an increased operating window for more effective crude oil dehydrators and desalters. Thus fewer and more compact process vessels can be used while still maintaining the required process performance. The paper also includes special considerations for slosh suppression, instrumentation and operating procedures, in addition to case stories with examples of compact equipment installed on FPSOs, SPARs, TLPs and semi submersibles.
This 2-pronge approach for crude oil dehydration and desalting combines high bulk water removal efficiency in the initial step and a high dehydration efficiency in the second step, providing benefits including:
an increased operating window in terms of crude oil inlet water cut and API gravity
use of smaller and more effective electrostatic treaters with lower CAPEX
a reduced OPEX from lower operating temperature, reduced demulsifier dosage and less dilution water for desalting
Further benefits include high frequency and amplitude modulated electrostatic fields, improved electrode configurations and materials, as well as improved fluid distribution inside the electrostatic treaters.