Chemical Aspects of a Cold Dispersion Pipeline System
Authors: Marsden S.S. 
Published: December 2007

Marsden, S.S., Member AIME, Stanford U.

This paper was prepared for the Oilfield Chemistry Symposium of the Society of Petroleum Engineers of AIME, to be held in Denver, Colo., May 24–25, 1973. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon requested to the Editor of the appropriate journal, provided agreement to give proper credit is made. provided agreement to give proper credit is made. Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussions may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

A proposal has been made to transport oil in the Arctic by dispersing it in brine, cooling the dispersion to below 30 degrees F, then pumping it through a buried pipeline. Such a pipeline cannot possibly damage the environment by thawing the permafrost. Various chemical aspects of this pipeline system are discussed. Corrosion is expected to be minor both because of the low solubility of oxygen in the brine and because of decreased corrosion rates at low temperatures. Brine for the dispersion may be prepared by partial freezing of sea water. Crude oils can be dispersed in brine with the aid of nonionic surfactants and then the dispersion broken at the pipeline terminal in heater-treaters. Condensible hydrocarbons can be redissolved in the dispersed cold oil and thereby transported in the same pipeline. Various environmental aspects of a cold dispersion pipeline are compared with those of a hot-oil line.

Introduction

Discovery of large reserves of oil in Northern Alaska almost 5 years ago has introduced petroleum engineers to a host of new and petroleum engineers to a host of new and challenging problems. We have long been used to dealing with the elevated temperatures of petroleum reservoirs and with hot fluids brought petroleum reservoirs and with hot fluids brought to the surface of the ground; now we have to work at the other end of the temperature scale. This has raised new problems, but in some cases it has alleviated old ones. We will discuss here some that we have encountered, but by no means try to review completely the valuable work done by many others.

Even those not in the field of petroleum are well aware that petroleum transportation in the Arctic is a major problem. While this is an area of work normally outside the realm of petroleum engineering, we have felt that it is a crucial subject and hence started considering it not long after the discovery of the Prudhoe Bay field. With only an elementary knowledge of permafrost, we realized that the classical approach of carrying hot oil through a buried pipeline was impossible in the Arctic. More than a decade ago, we started work on the rheology of foams and then of emulsions, and so were well aware of their distinctive flow properties. Applying this knowledge to the properties. Applying this knowledge to the Arctic oil transportation problems, we have put together the concept of what was at first called the cold emulsion pipeline system and is now called the cold dispersion pipeline system. Briefly, this involves dispersing crude oil in brine and pumping this dispersion through a brine pipeline at temperatures below 32 degrees F. The dispersed oil can safely carry redissolved, condensible hydrocarbons (LPG) at these temperatures, which a hot-oil line, of course, cannot do.