Analysis of oil drilling samples - by two-stage heating and hydrocarbon determination

摘要

The analysis comprises first heating the sample to vaporise the hydrocarbons present without pyrolysis of organic material, and determining the hydrocarbon content. The sample is then heated to a higher temp. to pyrolyse the insoluble organic material in the sample, and the amt. of hydrocarbons formed by pyrolysis is determined. The two results are then used to determine some characteristic of the oil-bearing formation. By plotting the two results (and/or their ratio) versus the depth from which the samples (esp. cuttings) were taken, information can be obtained about the location of matrix and reservoir rock, oil and gas zones, etc. The analysis is carried out in an appts. comprising a vertical tube surrounded by heaters at the bottom and top. The bottom heater is adjusted to give a temp. of 400 degrees C (pref. 200-400 degrees C), and the top heater gives a temp. of 400-700 degrees C (pref. 550-600 degrees C).