基于蒙特卡洛模拟的三维地质模型不确定性分析

Uncertainty evaluation of 3D geology model based on Monte Carlo simulation

在海上油田前期开发阶段钻井资料少,且中深层地震资料品质差,造成基于随机建模方法的地质模型存在较大的不确定性,如何快速准确地对地质模型开展不确定性分析是地质建模研究的难点。文中以地质储量和可采储量作为不确定性分析的定量指标,通过地质模型分析不确定性变量存在的原因和不确定性范围;同时,综合正交试验设计、响应曲面拟合的方法,在随机建模的基础上,应用蒙特卡洛模拟法计算模型地质储量和可采储量的概率分布,定量分析模型的不确定性,并排队优选出反映油藏风险和潜力的高、中、低3套模型,为油田的开发决策提供定量依据。

In the early stage of offshore oilfield development,there were little drilling data,and the quality of seismic data in the middle and deep strata was poor,which resulted in great uncertainty of geological model based on stochastic modeling method.So how to carry out uncertainty analysis of geological model quickly and accurately is the difficulty of research.In this study,geological reserves and recoverable reserves are proposed as quantitative indicators of uncertainty analysis.By analyzing the causes and range of uncertainties in geological models,the orthogonal experimental design and response surface fitting methods are synthesized.Based on random modeling,Monte Carlo simulation is applied to calculate the probabilistic distribution of geologic reserves and recoverable reserves.The uncertainty of this model is analyzed quantitatively,and three sets of models reflecting reservoir risk and potential are queued up to provide quantitative basis for oilfield development decision.