基于不确定性分析的页岩气单井SEC储量动态评估的一种方法——以CN区块Well-1井为例  

Dynamic evaluation methods for single-well shale-gas SEC reserves based on uncertainty analysis: An example from well-1, CN block

作　　者：李舫 吴娟[1] 杨家静[1] 汪华[1] 孙挺[2] Li Fang;Wu Juan;Yang Jiajing;Wang Hua;Sun Ting(Exploration and Development Research Institute,PetroChina Southwest Oil & Gasfield Company,Chengdu,Sichuan 610051,China;China University of Petroleum (Beijing),Beijing 102249,China)

机构地区：[1]中国石油西南油气田分公司勘探开发研究院 [2]中国石油大学(北京)

出　　处：《天然气勘探与开发》2018年第4期38-46,共9页Natural Gas Exploration and Development

摘　　要：四川盆地页岩气规模开采时间短,页岩气单井SEC储量动态评估方法处于探索阶段,特别是评估准确度较高的不确定性方法还未普遍应用。为此,在分析国外页岩气单井SEC储量不确定性评估方法的基础上,基于贝叶斯原理,应用拉丁超空间抽样方法与单井数值模拟相结合的方法建立了页岩气单井数值建模关键参数与单井最终总可采量(EUR)的函数关系式(代理函数),再对代理函数进行蒙特卡罗模拟,从而得到页岩气单井最终总可采及SEC储量的概率分布。研究结果表明:(1)页岩气单井数值建模关键参数为随机变量,呈截断正态分布;(2)页岩气单井最终总可采量与SEC储量也呈截断正态分布;(3)不确定性评估结果能够为确定性评估方法参数取值提供直接依据。结论认为:相比页岩气单井SEC储量确定性的评估方法,不确定性方法能综合考虑页岩气勘探开发中的不确定性因素,得到SEC储量概率分布,直接反映评估风险,更适合页岩气SEC储量的评估。同时,该评估方法增强了国际通用方法的实用性。In Sichuan Basin,due to short exploitation period on a large scale in shale gas,it’s essential to explore dynamic methods to evaluate single-well shale-gas SEC reserves especially under one condition that uncertainty evaluation method with high accuracy has not yet been universal.So,various foreign uncertainty evaluation methods for shale-gas SEC reserves were analyzed.Then,based on Bayesian principle,a functional relation(proxy function)between the key parameters of single-well numerical modeling and the single-well estimated ultimate reserve(EUR)was established by using Latin hyperspace sampling approach and numerical simulation.Finally,Monte Carlo simulation was carried out on the proxy function to clarify probability distribution of single-well EUR and shalegas SEC reserves.Results show that(1)the key parameters are random variable and expressed by a truncated normal distribution;(2)single-well EUR and SEC reserves also follow this distribution;and(3)results from uncertainty evaluation may provide a direct basis for parameter selection of deterministic evaluation method.In conclusion,compared with the deterministic method to evaluate shalegas SEC reserves,the uncertainty method is more suitable because it can comprehensively consider those uncertainties from shale-gas exploration and development,obtain the probability distribution of SEC reserves,and directly reflect the evaluation risk.

关 键 词：页岩气 SEC 最终总可采量 动态评估 贝叶斯原理 不确定性 数值模拟 蒙特卡罗 

分 类 号：TE328[石油与天然气工程—油气田开发工程]