排烃效率计算参数的校正及其应用

摘要

近年来人们通常利用常规地化资料结合物质平衡法对排烃效率进行计算，但由于岩石热解实验流程的原因导致一部分沸点超过300℃的重烃和一部分胶质-沥青质高温热分解产生的烃进入到裂解烃S2中（此两部分记为ΔS2），使得残留烃量（S1）被评价低了，干酪根潜在生烃能力（S2）被评价高了，使得应用校正前的热解参数计算得到的排烃效率比真实值偏高。利用已有的氯仿沥青“A”与族组成数据对热解参数进行校正，结合化学动力学法对松辽盆地J86井青一段泥岩进行了排烃效率计算。结果表明校正前后的排烃效率差别很大，排烃效率计算中参数的校正非常有必要，J86井校正后排烃效率比校正前的低15.7%；且干酪根类型越差，校正前后排烃效率相差的越多，Ⅱ型干酪根热解参数校正前排烃效率比校正后的高69.8%。%Expulsion efficiency is traditionally calculated by material balancing with standard geochemistry data. However, the original parameter values by rock pyrolysis experiment are inadequate for this way. Two keys neglected in the progress of rock pyrolysis experiment: heavy hydrocarbons with boiling points over 300℃, hydrocarbons formed during thermal decomposition of gum asphalt are considered part ofS2(markedΔS2 ), which reduces the value of S1 and increases the value ofS2.Thus, expulsion efficiency obtained by primary pyrolysis parameters is higher than true value. In this paper, pyrolysis parameters were calibrated, then the expulsion efficiency of mudstones in QingⅠ Member of J 86# was calculated with the corrected parameters and chemical kinetics. The studies show that the expulsion efficiencies obtained by the corrected parameters and the original ones are significantly different, the calibration of pyrolysis parameters is quite necessary. The data show that the expulsion efficiency of Jin 86# is decreased by 15.7%, and the poorer the kerogen type, the lower the reduction rate (kerogenⅡup to 69.8%).