煤层气藏多分支水平井非稳态产能模型  

Unsteady productivity model for multi-branched horizontal wells in coalbed methane reservoir

作　　者：姜瑞忠[1] 刘秀伟 王星[1] 郜益华 高岳 黄岩松 JIANG Ruizhong;LIU Xiuwei;WANG Xing;GAO Yihua;GAO Yue;HUANG Yansong(School of Petroleum Engineering,China University of Petroleum(East China),Qingdao City,Shandong Province,266580,China;CNOOC Research Institute Co.,Ltd.,Beijing City,100028,China;Zhidan Oil Production Plant,Yanchang Oilfield Co.,Ltd.,Yan’an City,Shaanxi Province,717500,China)

机构地区：[1]中国石油大学(华东)石油工程学院,山东青岛266580 [2]中海油研究总院有限责任公司,北京100028 [3]延长油田股份有限公司志丹采油厂,陕西延安717500

出　　处：《油气地质与采收率》2020年第3期48-56,共9页Petroleum Geology and Recovery Efficiency

基　　金：国家科技重大专项“低渗、特低渗油藏水驱扩大波及体积方法与关键技术”(2017ZX05013-002);国家自然科学基金项目“致密储层体积压裂缝网扩展模拟研究”(51574265)。

摘　　要：针对煤层气藏多分支水平井产能研究,从渗流力学基本原理出发,建立了考虑割理系统应力敏感性和基质系统非稳态扩散的煤层气藏多分支水平井非稳态产能数学模型,基于点源解理论、Pedrosa变换、摄动变换、Laplace变换、有限余弦变换、数值离散以及叠加原理,求解所建立的数学模型,利用Stehfest数值反演的技术绘制典型产量递减曲线,并依据曲线特点划分成9个不同的流动阶段,同时进行模型验证与对比;并对渗透率模量、分支井长度以及分支井个数等进行敏感性参数分析,总结出不同参数对生产动态的影响规律。煤层气藏多分支水平井产能动态的研究为合理开发煤层气藏提供了理论指导。In order to analyze the productivity of the multi-branched horizontal wells in the coalbed methane(CBM)reservoir,a productivity model for multi-branched horizontal wells in a CBM reservoir is proposed,which considers stress sensitivity in the cleat system and the unsteady diffusion in the matrix system based on the basic theory of the fluid flow mechanism through porous media.The mathematical model is solved through the methods of the point source function,Pedrosa transformation,Perturbation transformation,Laplace transformation,Finite cosine transformation,Element discretization,and Superposition principle.The typical production decline curve is plotted by Stehfest numerical inversion,which is divided into nine different flow regimes according to the characteristics of this curve.Also,the model validation and the comparison of the pseudo-steady diffusion and unsteady diffusion are conducted.Then sensitivity parameter analysis is carried out,such as the permeability modulus,length of branches and number of branches.We summarized the effect of different parameters on production performance.The related research enriches the studies of the production performance of multibranched horizontal wells in a CBM reservoir and provides certain theoretical guidance for the development of a CBM reservoir.

关 键 词：煤层气 应力敏感性 非稳态扩散 多分支水平井 敏感性参数分析 

分 类 号：TE32+8[石油与天然气工程—油气田开发工程]