by Dr. Franklin Foster, 2006
[note: this article made possible by support and funding from the Petroleum Society of CIM, Lloydminster Section
The innovative processes and technologies developed in the Lloydminster region have done much to help Heavy Oil contribute to the world's energy needs. The graph below shows how, as conventional oil reserves have declined, Heavy Oil has acted as a significant substitute.
- graph courtesy of Petroleum Technology Alliance Canada (PTAC)
However, much of the past production of Heavy Oil has been from "sweet spots" where the deposit is most like conventional crude. Although there are huge reserves of oil, in some cases as little as 5 % of the reserve has been recovered. In short, future production of Heavy Oil will require even more innovation to overcome increasingly difficult recovery conditions. Compounding these downhole difficulties is the need for economic sustainability and compliance with increasingly stringent environmental parameters.
Is it worthwhile pursuing new innovations to recover heavy oil? The answer is "yes!", in two distinct ways. Heavy oil deposits can be divided into two categories: accessible and inaccessible. Current technologies recover as little as 5 % of the in situ bitumen. If we could recover 50 % of such deposits, we could meet 50 % of all North American demand for at least 50 years. Then there are the even larger "inaccessible" reserves. This refers to deposits which are beyond the recovery of current methods and technologies.
These "inaccessible" reserves are
contained in a variety of problem locations.
(a) In carbonate formations such as shale and other "rocks" (These occur in about 30 % of Alberta)
(b) In deposits that are too thin for present technologies (eg. pay zones less than 10m thick)
(c) In areas where there is no reservoir pressure
(d) In highly fragmented deposits
Again, if, through R & D, we were
able to develop the processes and technologies to recover even 50 % of
these deposits, we could supply 50 % of North American demand for a
further 50 to 75 years. Some of these approaches have yet to be
thought of but among those in the conceptual stage are:
(a) Thermosyphons - could remove heat from reservoir, actually freezing water deposits to prevent them migrating into the oil reserves
(b) Surplus Sulphur - could be injected into the formation; again to create barriers to prevent water migration or overburden collapse
(c) Adaptation of coal mining technology to oil reserves; especially in the case of robotic mining equipment
(d) Injecting bacteria and nutrients in a warm water solution into the formation so the bacteria could convert the hydrocarbons into biogas such as methane
All of these possibilities will need considerable research and development, laboratory and field testing, before they can be applied commercially. One of the challenges is whether society, government and/or industry will have the will and imagination to pursue these possibilities. Obtaining 50 to 100 years worth of supply of secure petroleum reserves might well be worth the price.
“The only way of discovering the limits of the possible
is to venture a little way past them into the impossible” - Arthur C. Clarke’s Third Law