Abstract
Trinidad has tar sands resources of about 2 billion barrels of oil on land in the Parrylands/Guapo and Brighton areas. With an oil price of over USD 25 per barrel, commercial extraction of oil from Trinidad tar sands is viable but requires careful study. The relatively small extent of this tar sand (about 10,000 acres and with depths varying from surface to less than 500 feet) and with an oil in place of about 1000 times smaller than the Canadian tar sands, large scale surface mining and in-situ methods such as SAGD and VAPEX processes or their variants are not practical and also for environmental reasons.
In this study we explore the viability of oil extraction from Trinidad tar sands by radio frequency (RF) heating. RF heating does not require an overburden and is cheaper than SAGD and VAPEX and is also environmentally friendly since no steam, water and solvents are needed. Studies have also shown RF heating to be uniform, quicker and with deeper penetration than direct electrical (resistive) heating and an oil recovery between 50 to 80 % can be achieved. Preliminary studies indicated that Trinidad tar sands are wetting and with permittivity in the range 38 −100, which makes it suitable for RF heating.
The COMSOL Multiphysics® software was used to simulate oil sand samples contained within a copper chamber and the RF heating was applied via a dipole antenna. Temperature- time heating plots were generated using an operating frequency of 10 MHz and a current of 50 Amperes. This data and the physical properties of the tar sands were then simulated using the CMG software. The results indicated an oil recovery in the range 30-60%. An energy balance was then conducted and the results show that commercial extraction of oil from Trinidad tar sands by RF heating is viable with an oil price of over USD 25 per barrel.
