川东石炭系气藏产量风险量化模型构建  

A production risk quantification model for Carboniferous gas reservoirs,eastern Sichuan Basin

作　　者：余果[1] 刘海峰[1] 李海涛[2] 郑姝 刘林清[2] 敬雷 Yu Guo;Liu Haifeng;Li Haitao;Zheng Shu;Liu Linqing;Jing Lei(Planning Department,PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610051,China;Exploration and Development Research Institute,PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610041,China;Sichuan Chuangang Group Corporation Limited,Chengdu,Sichuan 610017,China)

机构地区：[1]中国石油西南油气田公司规划计划处 [2]中国石油西南油气田公司勘探开发研究院 [3]四川川港燃气有限责任公司

出　　处：《天然气勘探与开发》2022年第3期67-74,共8页Natural Gas Exploration and Development

基　　金：四川省科技计划项目“中国西南天然气大庆战略研究”(编号:2021JDR0401)。

摘　　要：目前国内外对天然气产量的风险量化研究尚处于起步阶段,主要原因是敏感因素的选取和量化存在不确定性,同时缺少完整开发周期的样本气藏进行验证。为了充分认识已开发气藏产量风险主控因素,为气藏开发技术对策调整和提高采收率提供理论依据,以25个川东石炭系气藏为研究对象,采用蒙特卡洛方法创新建立川东石炭系气藏产量风险量化模型。研究结果表明:①对比分析风险量化方法优缺点,明确蒙特卡洛方法可作为产量风险量化推荐方法;②通过层次分析法筛选出4个决策风险因素:稳产期采速、稳产年限、稳产期末采出程度、千米井深井均产能,并采用多旋回Gauss概率分布密度函数构建各因素与产量的概率分布曲线,明确已开发气藏产量风险主控因素;③建立稳产期产量计算公式作为蒙特卡洛模拟的目标函数,计算得到25个石炭系气藏年产量对应的最大概率范围为43.43×10^(8)~126.35×10^(8)m^(3),累计概率区间为14.59%~92.88%,实现了风险评价从定性到定量研究的突破。Globally,the research on risk quantification of natural-gas production is still in its infancy,mainly due to certain uncer-tainty to select and quantify some sensitive factors as well as the lack of gas reservoirs with a complete development cycle as samples for verification.To fully understand the main factors affecting production risk in the developed gas reservoirs and provide theoretical basis for technical adjustment and EOR,taking 25 Carboniferous gas reservoirs in eastern Sichuan Basin as examples,a production risk quantification model for the Carboniferous gas reservoirs in eastern basin was innovatively established by using the Monte Carlo method.After compared with some existing quantification methods,the Monte Carlo method was recommended.Four decision-making risk factors were defined by analytic hierarchy process,including gas production rate in stable production period,stable production period,recovery efficiency at the end of stable production period,and average productivity of kilometer-deep wells,and the probabil-ity distribution curve of each factor and production was constructed by the multi-cycle Gauss probability distribution density function to clarify the main factors affecting the production risk.The formula for calculating the production in the stable production period was established as the objective function for Monte Carlo simulation.The maximum probability of production in these 25 gas reservoirs ranges from 43.43×10^(8)m^(3)to 126.35×10^(8)m^(3),and the cumulative probability from 14.59%to 92.88%.The study result represents a breakthrough in risk assessment from the qualitative to the quantitative.

关 键 词：石炭系 天然气产量 风险量化 蒙特卡洛法 分布概率 累计概率 密度函数 

分 类 号：TE328[石油与天然气工程—油气田开发工程]