Heavy Oil Recovery - Principles, Practicality, Potential, and Problems
Authors: Ali S.M. Farouq 
Published: December 2007

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.
This paper was prepared for the Rocky Mountain Regional Meeting of the Society of Petroleum Engineers of AIME, to be held in Billings, Mont., May 15–16, 1974. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations mat 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 OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made.
Discussion of this paper invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

Abstract
This paper presents the principles, philosophy, plausibility, practicality, promise, prospects, potential, possibilities, and problems practicality, promise, prospects, potential, possibilities, and problems of heavy oil recovery. Methods of heavy oil recovery are briefly examined, and field results are summarized. The criteria for applying such methods to specific reservoirs are outlined in the light of field test results. Finally, the heavy oil reservoirs in the Rocky Mountain region are briefly described, and possible recovery techniques are considered.

Introduction
The term "heavy oil" usually implies crude oil having an API gravity of 25 degrees, or less. Once in a while, semi-solid hydrocarbons (e.g. bitumen in tar sands, asphalt, etc.) are included in this category. However, in the following discussion we shall only consider those heavy oils which are mobile at reservoir conditions, as established by some primary production. At the other end of the scale, crude oils having viscosities in excess of 30–40 cp are frequently referred to as "heavy oils".
Heavy crude oil has been recovered in the United States since the discovery of the Nacogdoches oilfield in Texas, in 1866. As of January 1, 1966, the heavy oil resources of the United States totaled 106.8 billion barrels, of which only 5.2 billion bbl were considered to be recoverable by conventional methods. It is estimated that of the remaining oil, some 45.9 billion bbl could be recovered by thermal methods, since this much oil occurs in reservoirs considered to be favorable for the application of such methods. The magnitude and the importance of this oil become readily evident if one considers the fact that the proved conventional oil reserves of the U.S. total only 36.3 billion barrels. In the past, recovery of heavy oils by rather exotic methods has been a marginal operation at best, since on one hand such recovery methods are expensive, and on the other, heavy oils sell for less than conventional oils. This has changed now, and with the increasing oil prices, recovery of heavy oils will become increasingly attractive from the commercial standpoint.
This paper examines various aspects of heavy oil recovery, and briefly considers the heavy oil potential of the Rocky Mountain region.

HEAVY OIL IN THE UNITED STATES
Over 2000 heavy oil reservoirs, occurring in 1500 fields in 26 states have been catalogued.