蒙特卡罗法在海上某油田储量评价中的应用

Application of Monte-Carlo method to OOIP estimation of an offshore oilfield

在油田开发前期的地质储量计算过程中,由于掌握的地质资料较少,采用确定法很难准确求取各储量计算参数,导致储量计算结果存在较大的不确定性。在介绍蒙特卡罗法原理、研究思路及研究方法,并对关键环节进行重点剖析的基础上,以海上某油田为例,通过卡方检验函数优选出各储量计算参数的概率分布数学模型,对整个地质储量进行随机模拟,确定储量的高、中、低方案值,并开展了储量敏感性研究;最后对该方法的适用性进行探讨。研究表明:在地质分析的基础上,且保证评价资料样本点充足的前提下,有效应用蒙特卡罗法,能够更客观地反映储量的评价结果,同时该方法可为开发前期或初期阶段国内外油气资源的同类评估提供指导。

It is difficult to ascertain every parameters of the OOIP calculation by determination method especially in the initial oilfield development stage because of the limitation of geological data. This paper presented the principle, workflow, and research method of Monte-Carlo method, and analyzed the key points. Taking an offshore oilfield as an example, this paper optimized the best probability distribution model of OOIP calculation parameters through Chi- square test function, determined the high, middle and low values of OOIP parameters by random simulation, and estimated the sensitivity. The applicability of the Monte-Carlo method was discussed finally. The study results show that the Monte-Carlo method is a very effective method to estimate the uncertainty of OOIP based on geological analysis and abundant data sample number, and the method is helpful for estimation of similar oil and gas field in the initial development stage.