区带油气资源量计算的解析概率法及其在柴达木盆地北缘的应用

Analytic probabilistic algorithm of calculating regional oil resource extent and its application in north margin of Chaidamu Basin

本文以柴达木盆地北缘地区为例 ,从各种控制油气藏形成的地质条件存在概率和资源量计算参数的概率分布出发 ,用解析概率法代替蒙特卡洛方法 ,依据条件概率理论和随机变量间期望与方差的各种关系 ,计算了区带内油 (气 )藏数目和油 (气 )资源量的概率分布。研究结果表明 ,解析概率法计算的油气资源量与实际情况符合较好。文章得出以下主要结论 :解析概率法计算速度快、精度较高 ;柴达木盆地北缘地区的油气资源主要集中于鄂博梁 号—葫芦山、鄂博梁 号—鸭湖。

Starting from the existing probability of different geologic condition controlling forming reservoir and probabilistic distribution of calculating parameters of resource extent, using analytic probabilistic algorithm to replace Monte Carlo method and based on conditional probability and every expectation variance relation between random variables, the paper takes north margin of Chaidamu Basin as an example to calculate the probabilistic distribution of the number of reservoirs and resource extent in that region. The results showed that using analytic probabilistic algorithm to predict resource extent fairly tallies with the actual situation and is believable. Finally, the major conclusions are as follows: ① analytic probabilistic algorithm has advantages of fast calculation speed and high precision; ② the petroleum resources in north margin of Chaidamu Basin are concentrated at Eboliang No.1 Hulushan and No.2 Yahu structural belts, Lenghu structural belt and Nanbaxian Mahai structural belt.