Energy saving in oilfields by using waste heat in the disposed water

Abstract

The present work aims to retrofit an existing Egyptian oilfield plant to improve desalter performance and reduce the power of crude oil shipping pumps. In this work, waste heat in disposed water that represents a value is used in heating brackish water injected over desalter and in heating crude oil before shipping. ASPEN HYSYS version 11 simulation software was used. The retrofit of the considered oilfield plant is based on the implementation of two new heat exchangers to recover waste heat in the disposed water. The results showed that using waste heat to heat the brackish water in the desalter from 30°C to 71.11°C will increase the operating temperature of the desalter and thus increase the sedimentation and separation rate. On the other hand, using waste heat in heating the crude oil before shipping from 37.78°C to 71.11°C reduces the oil viscosity from 1.536 cSt to 0.9735 cSt. Reducing the viscosity of the crude oil will reduce the pressure drop of the shipping pumps, and therefore the power required to pump the oil will be reduced. The presented retrofit design can be used as a guide in upgrading existing plants and plants under the design phase.

Keywords

• desalter
• viscosity reduction
• shipping pumps
• crude oil
• simulation