In Situ Recovery From the Athabasca Oil Sands-Past Experience And Future Potential, Part II
Authors: Redford D.A. , Luhning R.W. 
Published: March 2010

Abstract
In 1984 Redford(1) published a paper with a similar title, which outlined 60 years of field experience in recovering bitumen from Athabasca by in situ methods, commented on what had been achieved, and outlined the more promising recovery processes for different geological settings.
This paper covers the period from 1984 to the present. It outlines and discusses the eight field pilots which have been conducted since then or were not completely reported in the first paper. These are: The Texaco Horizontal Well Project, The Canterra Kearl Lake Project, The Gregoire Lake In situ Pilot, PCEJ Stoney Mountain Electrical Preheat Project, PCEJ Hangingstone Steam Simulation Pilots, UTF HASDrive Pilot, Steepbank HASDrive Pilot, and UTF SAGD Pilots. The potential for in situ recovery from Athabasca is discussed, taking into account the experience gained over the last 70 years. The paper concludes with some observations on the status of developing in situ recovery from Athabasca and where future progress is needed.

Introduction
The Athabasca oil sands deposit is, in many ways, the jewel in the crown of oil sands deposits. Its huge reserves and its thick pays with high porosity, permeability, and bitumen saturations have made it a tempting target. Yet ten years ago, 60 years of extensive experimentation both in the field and the laboratory had not yielded a commercial process and only one technically successful field pilot. It could be said that we had learned to ask the right questions, but did not yet have the right answers.
A lot has changed in the past ten years. The technology base laid down in earlier years has borne fruit. We have seen the completion of several successful pilots and the demonstration of one technology which promises to fulfill the dream of those early pioneers- low cost, reliable in situ bitumen recovery from Athabasca. This paper outlines the field experience over those last ten years, discusses it, and comments on where we stand.

Texaco Athabasca Horizontal Well Project
In 1980, Texaco, using a slant rig, drilled three horizontal wells in shallow oil sands (overburden 72 m, pay 63 m) at their pilot site south of the Fort McMurray airport. These wells (Figure 1) had about 400 m of horizontal section located near the base of the deposit and were completed open hole with a 0.76 mm keystone slotted sand exclusion liner. A production tubing extended approximately half way down the horizontal section. The project was supported in the late stages by the Alberta Oil Sands Technology and Research Authority (AOSTRA), which has now been merged into the Oil Sands and Research Division (OSRD) of the Alberta Department of Energy.
The recovery concept tested was similar to that used in the Petro-Canada MAISP project(2,3), with steam simulation of the outside wells followed by steam drive from the centre well to the two outside wells.
The pilot experienced severe difficulties from the start due to two of the major reasons for pilot failure in Athabasca-reservoir heterogeneity and sand exclusion.