Take a look at Jake's latest thread:
http://ecorenovator.org/forum/geothe...o-heating.html
He has been doing research on an oil trap/separator to use in his new concoction. As I write this post, he is gearing up for yet another build of groundbreaking (literally) and unconventional nature. His homework could save you some time and effort rigging up an oil trap.
I wish you both good luck and godspeed.