INVERSION POINT OF EMULSIONS AS A MECHANISM OF HEAD LOSS REDUCTION IN ONSHORE PIPELINE HEAVY OIL FLOW

Abstract

This work addresses the transportation of viscous crude oil as concentrated oil-in-water (O/W) emulsions flowing in a partially submerged onshore pipeline. The main goal of this study is to analyze the effects of inversion point of the water-in-oil emulsion in the pressure drop with the aid of Pipesim® software. Pressure drop is determined by applying the Dukler correlation (Taitel and Dukler, 1976) to represent dead oil viscosity as a function of temperature, and API density using the Hossain correlation (Hossain et al., 2005). The Brinkman model (Brinkman, 1952) is applied to calculate the viscosity of the emulsion, with the Brauner and Ullmann (2002) equation for the water cut off method (inversion point). The pipeline, of 3,600 m and 4 inches in diameter, transports the oil and consists of three sections. The first and third sections are above ground and are in contact with the external environment. The intermediate section is sitting on the river bed and is the critical part of the pipeline, once high heat losses are observed. The results of this 1D and non-isothermal problem show that water cuts of 5 and 6%, for low heat exchange and high heat exchange, respectively, make it possible to transport the oil, as an oil-in-water emulsion, through the entire extension of the pipeline. However, a water cut of 10% creates a high-pressure drop in the system, assuring the movement of the fluid in long sections without compromising the system operation. The use of isolation influences the temperature gradient but doesn’t have a high influence on pressure gradient compared to emulsions.