The Department of Energy web site I linked above tracked EVERY sale and exchange of oil for the SPR. What you claim never happened.
Draining the SPR might cause a tempory blip on the spot market and give a few buyers a good deal but it would do nothing to affect the price of oil as it would do nothing to increase production only consumption.
From the comments on threads like this it is clear the public has but a foggy notion of how economics works. Sad.