Current Status of In-Situ Recovery From the Tar Sands of Alberta
Authors: Ali S.M. Farouq 
Published: March 2010

Abstract
A number of schemes have been proposed and tested for the in-situ. recovery of oil from the tar sands of the Athabasca, Cold Lake, Wabasca and Peace River areas of Alberta. The present paper reviews the field tests that have been conducted or are currently underway. An attempt is made to put together the available information on these field tests, in order to assess the technology of in-situ exploitation of tar sands. In particular, field tests of the combination steam injection process in the Athabasca and Peace River regions, of cyclic steam stimulation in the Cold Lake region and of in-situ combustion in the Athabasca region are critically reviewed, and the project statistics a:te analyzed in order to evaluate and compare these methods, The operational problems encountered are described, and it is shown that the conditions in the tar sands areas are such that a combination recovery method has the best chance of success, Several other in-situ, recovery methods that have been proposed including in-situ. hydrogenation and cracking, combined miscible and thermal methods, and underground nuclear detonations are briefly discussed and evaluated.

Introduction
THE TAR SANDS OF ALBERTA represent an enormous hydrocarbon deposit, covering some 19,000 square miles and totaling 895 billion barrels of bitumen, Table 1 gives a breakdown of this deposit, also indicating the volumes of the recoverable synthetic crude(l,2). It is seen that only 8.3 per cent of the deposits occur in the 0-150-ft overburden thickness range, which is currently considered to be the range within which surface mining and processing methods are applicable. These data are based on a cut-off bitumen saturation of 2 per cent by weight (3 per cent for Cold Lake). It is noteworthy that 69~9 per cent of the total deposits occur in the Athabasca region. Also, 15.1 per cent of the deposits occur under overburden 150-500 ft in thickness, and are currently deemed to be unexploitable
(figure in full paper)
by either surface mining or in-situ methods (exceptions will be noted below), Figure I, based on Reference (3), shows the distribution of overburden in the Athabasca region.
This article reviews the results of some of the field tests conducted in the tar Bands formations. The discussion is based on published articles, news items and other public records, together with the author's calculations. At the present time, at least 11 experimental in-situ recovery projects are in operation in the tar sands area, and even a larger number is planned for the next two years. At least 23 projects have already been conducted and terminated for various reasons. Very little information derived from these tests has been published to date, Figure 2 shows the locations of some of the terminated and current in-situ projects. Other projects not shown include those of Cities Service, Tenneco, WECO, Numac and BP, which are in the planning stages.
Although oil recovery from tar sands by surface mining methods has been adequately established, the in-situ operations are still experimental and account for a net production of about 2000 B/D.