The November crude contract closed on a loss of 22 cents today, settling at $81.22 per barrel as the dollar strengthened on a bullish September payrolls report. Black gold closed the week 0.5% lower than its close at $81.66 last Friday. Crude slipped on the dollar's gain because it's a dollar-denominated commodity and becomes more expensive in other currencies as the greenback rallies. However, the payrolls report also lends some support to crude, since it suggests a healthy economy and strong future demand.

Other petroleum products followed crude's lead to close on a loss. November heating oil lost fractions of a cent to close at $2.2235 per gallon, and November reformulated gasoline shed 0.29 cent to close at $2.0493 per gallon. Elsewhere in energy, November natural gas lost 4.6% to finish at $7.073 per million British thermal units, but held onto a gain of 2.9% for the week.

The Oil Service HOLDRS Trust closed on a loss of about 0.7%, slipping below its 10-day moving average in the process. However, the trust remains gapped above support from its 10-week and 10-month moving averages.