页岩气分段压裂水平井非稳态渗流模型UNSTEADY SEEPAGE MODEL OF THE SHALE-GAS STAGED FRACTURED HORIZONTAL WELL
韩国庆,任宗孝,牛瑞,李斌,师俊峰,吴小军
HAN Guoqing,REN Zongxiao,NIU Rui,LI Bin,SHI Junfeng,WU Xiaojun
摘要(Abstract):
有关应力敏感页岩气藏分段压裂水平井渗流的解析模型很少,在考虑页岩气吸附解吸附、基质内非稳态扩散及应力敏感的前提下,应用拉式变换、摄动变换、镜像原理以及叠加原理等方法,建立了页岩气分段压裂水平井半解析模型。模型计算结果表明,页岩气分段压裂水平井可分为6个渗流阶段,即线性流、第一径向流、双径向流、天然裂缝系统径向流、窜流阶段和整个系统径向流动。应力敏感主要影响后5个流动阶段,考虑应力敏感的无因次井底压降是不考虑应力敏感的几倍之多,且开发后期无因次压降导数曲线往往上翘,表现出封闭边界影响的特征。如果计算分析时不考虑应力敏感的影响,计算结果会产生较大的误差,且会得出错误的试井解释。所建的半解析模型为快速预测页岩气分段压裂水平井的产能、认识压裂水平井渗流规律和评价分析压裂效果,提供了一种非常有用的方法。
The analytical model is few for the flow of the staged fractured horizontal well in the shale gas reservoir.The calculated results of the model show that the flow can be divided into six stages i. e. linear flow,the first radial flow,double radial flow,radial flow of the natural fracture system,interporosity flow and whole-system radial flow. The dimensionless bottom-hole pressure drop considering the stress sensitivity is several times of that without considering the stress sensitivity,and moreover the dimensionless pressure drop curve often warp in the later period of the development,so the characteristics of the sealed boundary influence are well presented. If do not consider the influence of the stress sensitivity when calculating and analyzing,the calculated results will produce larger error,and furthermore the wrong well test interpretations may be concluded. The built semi-analytical model has pro-vided one useful method for rapid predicting the productivity of the staged fractured horizontal well,understanding the flow laws of the well and evaluating & analyzing the effects of the fracturing.
关键词(KeyWords):
页岩气;水平井;渗流解析模型;应力敏感;摄动变换;分段压裂;源函数
shale gas;horizontal well;flow analytical model;stress sensitivity;perturbation transform/transformation;staged fracturing;source function
基金项目(Foundation): 国家“973”“陆相致密油高效开发基础研究”(2015CB250900);; CMG Reservoir Simulation Foundation;; 国家科技重大专项“复杂结构井优化设计与控制关键技术”(2011ZX05009-005)
作者(Author):
韩国庆,任宗孝,牛瑞,李斌,师俊峰,吴小军
HAN Guoqing,REN Zongxiao,NIU Rui,LI Bin,SHI Junfeng,WU Xiaojun
DOI: 10.19597/J.ISSN.1000-3754.201607008
参考文献(References):
- [1]李相方,蒲云超,孙长宇,等.煤层气与页岩气吸附/解吸的理论再认识[J].石油学报,2014,35(6):1113-1129.
- [2]张茂林,杨龙,梅海燕,等.考虑吸附相视孔隙度的页岩气藏物质平衡方程[J].大庆石油地质与开发,2017,36(1):156-160.
- [3]张艺钟,张茂林,喻高明,等.页岩气藏单井产能计算方法[J].大庆石油地质与开发,2017,36(1):161-164.
- [4]伍岳,樊太亮,蒋恕,等.四川盆地南缘上奥陶统五峰组—下志留统龙马溪组页岩矿物组成与脆性特征[J].油气地质与采收率,2015,22(4):59-63,68.
- [5]王南,裴玲,雷丹凤,等.中国非常规天然气资源分布及开发现状[J].油气地质与采收率,2015,22(1):26-31.
- [6]姜瑞忠,张伟,滕文超,等.页岩气藏三重介质窜流参数分析[J].特种油气藏,2017,24(3):1-7.
- [7]方文超,姜汉桥,李俊键,等.致密储集层跨尺度耦合渗流数值模拟模型[J].石油勘探与开发,2017,44(3):1-8.
- [8]赵文智,李建忠,杨涛,等.中国南方海相页岩气成藏差异性比较与意义[J].石油勘探与开发,2016,43(4):1-12.
- [9]Sevenster P G.Diffusion of gases through coal[J].Fuel,1959,38(1):403-418.
- [10]Bello R O,Wattenbarger R A.Multi-stage hydraulically fractured horizontal shale gas well rate transient analysis[C]//North Africa Technical Conference and Exhibition.Society of Petroleum Engineers(SPE),2010.
- [11]Warren J E,Root P J.The behavior of naturally fractured reservoirs[J].SPE,1963,J3(3):245-255.
- [12]Kazemi H.Pressure transient analysis of naturally fractured reservoirs with uniform fracture distribution[J].SPE 002156A,1969.
- [13]Brown M,Ozkan E,Raghavan R,et al.Practical solutions for pressure transient responses of fractured horizontal wells in unconventional shale reservoirs[J].SPE 125043,2011.
- [14]姚军,殷修杏,樊冬艳,等.低渗透油藏的压裂水平井三线性流试井模型[J].油气井测试,2011,20(5):1-6.
- [15]苏玉亮,王文东,盛广龙.体积压裂水平井复合流动模型[J].中国石油大学学报(自然科学版),2014,38(3):504-510.
- [16]田冷,肖聪,刘明进,等.考虑页岩气扩散的多级压裂水平井产能模型[J].东北石油大学学报,2014,38(5):93-102.
- [17]樊冬艳,姚军,孙海,等.页岩气藏分段压裂水平井不稳定渗流模型[J].中国石油大学学报(自然科学版),2014,38(5):116-123.
- [18]Pedrosa O A Jr.Pressure transient response in stress-sensitive formations[R].SPE 15115,1986.
- [19]Ozkan E,Raghavan R.New solutions for well test analysis problems:Part 1 Analytical considerations[J].SPEFE,1991:359-368.
- [20]Chen C,Raghavan R.A multi-fractured horizontal well in a rectangular drainage region[R].SPE 37072,1996.
- [21]Stehfest H.Numerical inversion of Laplace transforms[J].Commun.ACM,1970,13(1):47-49.
- [22]Zerzar D,Tiab Y B.Interpretation of multiple hydraulically fractured horizontal wells[R].SPE 88707,2004.
- [23]Huang T,Guo X,Chen F F.Modeling transient flow behavior of a multiscale triple porosity model for shale gas reservoirs[J].Journal of Natural Gas Science and Engineering,2015,23:33-46.
- 页岩气
- 水平井
- 渗流解析模型
- 应力敏感
- 摄动变换
- 分段压裂
- 源函数
shale gas - horizontal well
- flow analytical model
- stress sensitivity
- perturbation transform/transformation
- staged fracturing
- source function