盆地模拟的参数敏感性与风险分析

The parameter sensitivity and risk analysis for basin modeling

提出盆地模拟的参数敏感性与风险分析的一种方案:根据油气勘探实际选择关键性参数,对之进行敏感性分析;用蒙特卡罗法求出模拟结果的概率分布,实现盆地模拟的风险分析。在塔里木盆地的盆地模拟实例分析中,选择的敏感性参数为剥蚀厚度、古地热梯度和R_o-深度曲线。对模拟结果的分析表明:剥蚀厚度对埋藏史、地温史、R_o史和生、排油史影响较大,古地热梯度对地温史、R_o史和生、排油史影响较大,R_o对R_o史和生、排烃史影响很大。基于这3个参数的风险分析的模拟结果明显地优于以前的确定性计算结果。

A program of the parameter sensitivity and risk analysis of basin modeling is presented, in which the crucial parameters are selected according to the petroleum exploration and their sensitivity. The probability distribution of simulation results is figured out by the Monte Carlo method so as to conduct the risk analysis of basin modeling. The method is applied to the Tarim Basin as a case study, and the selected sensible parameters are the erosion thickness, the paleo-geothermal gradient and the curve of R_o versus depth. The simulation suggests that the erosion thickness could strongly affect burial, paleo-temperature,Ro and oil generation-expulsion histories, and paleo-geothermal gradient affects the geothermal, R_o and oil generation-expulsion histories, and the curve of R_o versus depth greatly affects the R_o and hydrocarbon generation-expulsion histories. The risk analysis results based on the three parameters are obviously superior to previous results. The technique makes basin modeling from the traditional determination model to the advanced risk analysis model.