Through a comparison of various indices of adsorbed hydrocarbon: it isfound that index of C₈⁺ is not affected by surface interfering factors, and itsanomalies might indicate the information of underground oil and gas. Using theC₈⁺ index, we have delineated five anomalies, of which No. I anomaly has ledto the discovery of oil flow of industrial significance through drilling, No. Ⅱtal No.Ⅲ anomalies show very great oil-gas exploration value, No. Ⅳ anomalyalso has certain exploration significance, but No. V seems of no explorationvalue. In addition, No. V geothermal anomaly has developed into an oil fieldcalled the Sanchunji oil field. Industrial oil flow was revealed through drillingat a 2nd grade hydrochemical anomaly (No. 2). These data provide convincingevidence for the effectiveness of the geochemical method in the explorationof oil-gas field.