Speculation does have some impact, but speculation alone simply could not cause all of the price increase we've had in the last three and a half years. It's mostly being driven by increased demand (especially in booming China), plain and simple, in the same way that the huge spike in the late '70 and early '80s was driven by the artificial supply cuts created by OPEC.
Great! Quantify it!
How much American drilled oil is being delivered in that market?