Pipelining crude oils and tars containing dissolved natural gas at sub-freezing temperatures in order to avoid environmental damage

Abstract

Abstract Crude oils and tars, such as those obtained from the Prudhoe Bay Oil Field and the Athabasca Tar Sands, can be efficiently transported through a large diameter insulated pipeline at temperatures below 32* F., for example, between about 15* to 30* F., in the form of 40 to 70 percent oil-in-brine emulsions containing salts dissolved in the water in amounts sufficient to prevent freezing at said temperatures. These operating conditions permit the insulated pipeline to be buried in the ground without causing thawing of the permafrost which will lead to significant damage to both the environment and the pipeline. Subsurface construction of a pipeline of this sort has considerable economic advantage over the above-ground, supported construction required for a heated oil pipeline to avoid environmental damage. Dissolution of gas in the crude oil at these low temperatures, thus allowing transport of the gas in the same pipeline, will also add considerable economic advantage. Even at these low temperatures, the emulsion has an effective viscosity comparable to that of the oil alone at much higher temperatures so that energy consumption for pumping is at an acceptable level. On arriving at the discharge terminal, the cold emulsion can then be broken down into its constituents by heating the same either with or without the addition of demulsifying chemicals.

Inventors

• 👤 Sullivan S Marsden Jr
• 👤 Stephen C Rose

Bibliographic Details