Abstract

Dragon and White Tiger crude oils are two different kinds of paraffin crude oils of Vietnam. The screening studies on their fluidity changes under the influence of magnetic forces have been completed. The relationships between their viscosity changes and magnetic force strength, temperature, and duration of treatment were obtained, the optimal conditions for the viscosity reducing were found. The changes in paraffin crystallization under magnetic fields were studied using scanning electronic microscopy (SEM). The possibilities to defense and remove wax clogging and deposition obtained by magnetic treatment was also studied and proved. Base on these data, the mechanism of the influence of magnetic fields on paraffin deposition control was proposed. The data can also serve as a basic in designing and construction high effective magnetic tools to improve liquidity of high waxy crude oils in this area.

Introduction

Paraffin or wax deposition has been recognized as a major problem from the inception of oil industry all over world. It can occur and present a lot problems in oil production, transportation and storage. These cause the reduced crude oil pumping rate, severe start up problems after pipeline shut down and wax deposition. Paraffin deposits on the wall of down hole turbulars and other places like near entrances and exit of chokes, collars of similar restrictions in the flow path. Among existing two physical and chemical groups of methods to control this problem, wax crystal modifiers maybe the best in able to resolve, partly, these low temperature troubles by modifying the rheological properties of waxy crudes and decreasing wax deposition, resulting in a better pump ability and restability. Despite these advantages, the chemicals are expensive, environmentally hazardous, they also are very sensitive, they can work effectively only on specific crudes.

There was one more method, the magnetic technology, which was based in an applied magnetic fields, can very successfully remove or inhibit crude oil gathering deposits, both organic and inorganic without affecting the crude characteristics. Despite the magnetic technology has been cited in the literature and studied since nineteenth century, while naturally occurring magnetic mineral formations were used to decrease the formation of scale in cooking and laundry applications, and now a day, a thousand of magnetic fluid conditioners (MFC) have been installed in oil wells in many places in the world [1,2], the mechanisms of its effects on deposition control, especially on crude oil wax deposition was not so far clearly studied and proved. The purpose of this study is to confirm that magnetic fields effect on liquidity of crude oils via fluid viscosity and paraffin crystallization process, and try to find out the mechanisms of these effects.

This content is only available via PDF.
You can access this article if you purchase or spend a download.