Another Look at Oil Transportation in and From the Arctic Environment

Title	Another Look at Oil Transportation in and From the Arctic Environment
Authors	Marsden Jr., S.S., Stanford U.; Ozarar, I., IMAS Foreign Trade Co.
Source	International Arctic Technology Conference, 29-31 May 1991, Anchorage, Alaska
Copyright	Copyright 1991, Society of Petroleum Engineers, Inc.
Language	English
Preview	Abstract Transportation of crude oil in the Arctic presents unique problems which are not easily handled by the usual hot oil problems which are not easily handled by the usual hot oil pipelines plus the very large tankers operating in restricted pipelines plus the very large tankers operating in restricted coastal waters. The work described here presents a solution which would allow completely buried, cold operating pipelines along with tankers carrying an easily dispersible crude oil emulsion which would not form massive oil slicks on coastal waters in the event of an accident. Sadlerochit crude oil emulsions were prepared in 10% NaCl brines using an especially developed procedure based on an ultrasonic emulsifier. The oil concentration was varied from 10% to 90% (vol.) with the higher concentration ones being HIPR (high-internal-phase ratio) O/W emulsions. The lower concentrations were Newtonian fluids and the higher concentration ones pseudoplastics. A new kind of variable head rheometer was developed to measure the shear stress-shear rate Characteristics at various low as well as ambient temperatures. The proposed transportation system would require continuous preparation of say 80% oil in 10% NaCl brine O/W emulsions, cooling them to say 20 deg. F and pumping them in completely buried pipelines. Use of the low temperatures would prevent any thawing of the permafrost and for a new pipeline would be considerably less expensive to construct than pipeline would be considerably less expensive to construct than hot oil line built on supports. At the pipeline terminal, the HIPR emulsion would be run onto ordinary tankers and transported to refinery markets in temperate climates, where the emulsions would be broken in heater-treaters. In the event of a tanker accident such as the Exxon Valdez, the O/W emulsion would be fully dispersed in the ocean without formation of a surface slick and it would then be consumed by microorganisms naturally found in the ocean. Introduction The transportation of petroleum in the Arctic both by pipelines and tankers presents problems beyond those in the pipelines and tankers presents problems beyond those in the rest of the world. This was forcefully brought to the public's attention by the Exxon Valdez disaster along with the slow, expensive efforts to alleviate the environmental aftermath. The same public has also tended to ignore the long, successful operation of the Alyeska Pipeline and has forgotten the predicted dire results of many environmental groups. We must predicted dire results of many environmental groups. We must continue to be vigilant about the successful operation of this engineering marvel, because any failure will be pounced on by the media, and this will impact many other operations of the petroleum industry, particularly in the Arctic. petroleum industry, particularly in the Arctic. Transportation of oil and gas in Alaska has interested us since the discovery of the Prudhoe Bay fields in 1968, but we were aware of some of the problems to be considered (e.g., permafrost) long before that. Our earliest work was on the permafrost) long before that. Our earliest work was on the concept of a cold-crude oil-in-brine transportation system which involved the use of both a completely buried pipeline and also tankers of the usual sort used for ordinary crude oil. Brine instead of water was needed for preparing the emulsions so that they could be pumped at sub-0 deg. C temperatures without thawing the permafrost. The results of this work have been presented in one SPE paper, several MS degree research presented in one SPE paper, several MS degree research reports, one U.S. Patent and a PhD dissertation. The scientific work on the preparation and properties of cold-crude oil-in-brine emulsions which went into the dissertation are the basic for this paper, and more details on the results can be found there. This work was not continued directly because we focused our attention on another novel transportation concept, namely, the transportation of crude oil as a cold dispersion in methanol with the latter being made from natural gas at Prudhoe Bay in barge-mounted methanol plants. The results of this work have been presented in another dissertation, a paper, and another a U.S. patent (also issued in Canada). By the time this work was completed, the Alyeska Consortium had already decided on its hot oil in elevated pipes concept even though there were many reasons to believe it would be more expensive than our design. In time, other pipelines may be built in either the Alaskan, Canadian or Siberian Arctic, and we believe that these two pipeline concepts should be seriously considered at that time. pipeline concepts should be seriously considered at that time. There is very good evidence based on the work of others that if these emulsions-in-brine or dispersions-m-methanol had been in the Exxon Valdez, the environmental impact would have been minor, and the reasons for this will also be discussed in the paper. P. 173
Number of Pages	6 From: http://www.onepetro.org/mslib/servlet/onepetropreview?id=00022073&soc=SPE