If you hit it with dispersant it can because they interact with the surface tension of the oil. But overall with something that light you won't see near as much of it sink naturally right away vs tar sands at less the 10. But don't forget an oils gravity the second it gets spilled start to change. As the evaporation process takes out all of the lighter hydrocarbons the gravity gets lower and lower and eventually the oil breaks down and what's left sinks down into the water column. By the time bakken oil starts to sink calling it oil wouldn't be technically accurate since it's really just the heavier base components left and they don't last all that long either if it's warm out and they don't get buried in the bottom.

