After highlighting the strong significance of oil sands within the overall global energy mix, JV talked the audience through the three laboratory-based core analysis techniques available to determine the saturation of oil within recovered core samples. These are: Dean Stark (DS) - the simple-sample solvent distillation method most commonly used by the Canadian oil sand industry; Low field Nuclear Magnetic Resonance (LNMR), and an alternative solid phase multi-sample solvent extraction method, CEPSat™, which is now being developed as a rapid and economical oil recovery tool.
JV discussed the pros and cons of each method. DS delivers accurate results, but these take time (between six and 24 hours for each extraction). Another issue is the sheer scale of the equipment required: a single DS occupies a fume hood space of approximately 20x20cm and most oil sands laboratories in Canada have at least 100 of these performing around 200 DS per day in two 12-hour work shifts. While LNMR is said to be fast, non-destructive and inexpensive, it cannot be used as a standalone device, requires particle size analysis and corrections by technical personnel, and does not recover the oil, as DS or CEPSat™ do. CEPSat™ has attractive time and cost-efficiency benefits, but does require: greater sample handling care due to the small amount of sample used; optimal operating conditions, with room temperature control; good quality solvent, and regular control, especially if the technique used in aremote area with potential contamination or impure solvent.
Lab equipped with two units can run up to 400 samples per day, allowing stricter control on the exploration operations, proving therefore CEPSat™ method’s efficiency.
JV explained that Kirk Petrophysics first encountered the new technique in Madagascar, where they were asked to carry out comparison testing against the DS technique for a TOTAL E&P onshore heavy oil project. During the campaign, more than 15,000 CEPSat™ tests were carried out against 800 DS measurements on 16km of core, demonstrating that the new tool could not only achieve the same results as DS, but could do so 10 times faster, using a significantly smaller laboratory footprint. Kirk’s study also concluded that CEPSat™ was capable of quantifying and isolating petroleum products from any core sample.
Following the Madagascar campaign, Kirk embarked on a further study to find a correlation between the new technique and other grades of oil sands found elsewhere in the world. The study focused on samples of high, medium and low grade oil sands from different North American locations. It concluded that the technique could efficiently extract all the bitumen out of the core to the same degree as DS. Using DCM solvents, a unique correlation could be established for medium and high degree ore, while, for low grade ore, the solvent was not good enough to overcome the clay and organic content. The CEPSat™ has shown great potential with studies having concluded that the extraction process is effective. Further study will be carried out to investigate the effect of different solvent on the rare extraction.
JV told the audience: “The CEPSat™ method for oil extraction is a powerful tool for the oil exploration industry. Its main goal is its capability to run multiple analyses in a relatively short time-we have demonstrated that a lab equipped with two units can run up to 400 samples per day. This efficiency allows stricter control on the exploration operations.”
Kirk Petrophysics will present their study findings at the Symposium of Core Analysis, Napa Valley, in September this year.
Acknowledgement: This technology has been developed by TOTAL S.A.
TOTAL S.A. (2013), Patents No FR2958752B1 - CA2736096 - MG2011/011