考虑滑脱效应的页岩气压裂水平井产能评价理论模型PRODUCTIVITY EVALUATING THEORETICAL MODEL OF THE FRACTURED SHALE-GAS HORIZONTAL WELLS CONSIDERING GAS SLIPPAGE EFFECT
张磊,李相方,徐兵祥,石军太,龚崛,张保瑞
ZHANG Lei,LI Xiangfang,XU Bingxiang,SHI Juntai,GONG Jue,ZHANG Baorui
摘要(Abstract):
水平井多级压裂和储层低孔低渗特性使页岩气呈现长期的瞬态线性流,吸附气的解吸和纳米级基质孔隙中气体的滑脱效应使页岩气藏的产气规律不同于常规气藏。基于瞬态线性流和吸附气解吸的特点,考虑基质孔隙中气体的滑脱效应,建立并求解页岩气多级压裂水平井产能评价模型。在此基础上,通过数值反演和计算机编程绘制页岩气多级压裂水平井产量典型曲线,总结出页岩气多级压裂水平井包含裂缝线性流、双线性流、基质线性流和边界效应4个流动阶段。参数敏感性分析发现储容比、窜流系数、气藏尺寸对典型曲线的影响较大。通过分析滑脱效应对产能的影响,得到滑脱效应考虑与否的判定图版,对页岩气产能模型的选择具有指导意义。
Multi-stage fracturing of the horizontal wells and low porosity and permeability characteristics of the reservoirs make shale gas present a long-period transient linear flow in production,the absorbed gas desorption and the gas slippage effect in nano-pore matrix make shale-gas producing laws different from the conventional ones.Based on the features of the transient linear flow and desorption,considering the slippage effect,the production forecasting model for these kinds of horizontal wells is established and calculated.On the basis of the above,through the numerical inversion and computer programming,the typical curves of the well production are drawn.And furthermore four flow stages are summarized in the production of multi-stage fractured horizontal shale-gas wells:linear flow in fractures,bilinear flow,linear flow in matrix and boundary-dominated flow.The parameter sensitivity analyses show that the storativity ratio,interporosity flow coefficient and gas reservoir sizes possess more significant effects on the shapes of the typical curves.Through analyzing the effects of the gas slippage on the gas productivity,the identifying chart boards considering the effects or not are obtained.All the achievements gained above have a certain ref-erences to the selection of shale-gas productivity evaluation models.
关键词(KeyWords):
页岩气;多级压裂;水平井;产能评价;滑脱效应;储容比;窜流系数;气藏尺寸
shale gas;multi-stage fracturing;horizontal well;productivity evaluation;slippage effect;storativity ratio;interporosity flow coefficient;gas reservoir size
基金项目(Foundation): 国家自然科学基金(50974128);; 国家重大基础研究发展计划(973计划)项目(2009CB219606);; 国家科技重大专项课题(2011ZX05038-4)
作者(Author):
张磊,李相方,徐兵祥,石军太,龚崛,张保瑞
ZHANG Lei,LI Xiangfang,XU Bingxiang,SHI Juntai,GONG Jue,ZHANG Baorui
参考文献(References):
- [1]江怀友,宋新民,安晓璇,等.世界页岩气资源勘探开发现状与展望[J].大庆石油地质与开发,2008,27(6):10-14.
- [2]孙赞东,贾承造,李相方,等.非常规油气勘探与开发[M].北京:石油工业出版社,2011:865-1116.
- [3]Inamda A,Malpani R,Atwood K,et al.Evaluation of stimulation techniques using microseismic mapping in the eagle ford shale[R].SPE 136873,2010.
- [4]Bello R 0.Rate transient analysis in shale gas reservoirs with transient linear behaviour[D].PhD Dissertation,Texas A&M U,College Station,Texas,2009.
- [5]Bello R O,Wattenharger R A.Rate transient analysis in naturally fractured shale gas reservoirs[R].SPE 114591,2008.
- [6]Brohi I,Pooladi-Darvish M,Aguilera R.Modeling Fractured horizontal wells as dual porosity composite reservoirs-application to light gas,shale gas and tight oil cases[R].SPE 144057,2011.
- [7]李武广,鲍方,曲成,等.翁氏模型在页岩气井产能预测中的应用[J].大庆石油地质与开发,2012,31(2):98-101.
- [8]关富佳,吴恩江,邱争科,等.页岩气渗流机理对气藏开采的影响[J].大庆石油地质与开发,2011,30(2):80-83.
- [9]Philip H N.Pore-throat sizes in sandstones,tight sandstones,and shales[J].AAPG Bulletin,2009,93(3):329-340.
- [10]Ertekin T,King G A,Schwerer F C.Dynamic gas slippage:a unique dual-mechanism approach to the flow of gas in tight formations[J].SPE 12045,1986.
- [11]刘高波,刘荣和,冯文光,等.低渗透气藏非达西渗流研究[J].大庆石油地质与开发,2007,26(1):65-67.
- [12]Ozkan E,Raghavan R,Apaydin 0 G.Modeling of fluid transfer from shale matrix to fracture network[R].SPE 134830,2010.
- [13]李彦尊,程时清,袁玉金,等.考虑气体滑脱效应的低渗透气藏试井典型曲线[J].大庆石油地质与开发,2009,28(4):72-75.
- [14]庄惠农.气藏动态描述和试井[M].北京:石油工业出版社,2004:284-287.
- [15]Bumb A C,.McKee C R.Gas well testing in the presence of desorption for coalbed methane and devonian shale[J].SPE Formation Evaluation,1988,3(1):179-185.
- [16]Van Everdingen A F,Hurst W.The application of Laplace transformation to flow problems in reservoirs[J].Petroleum Transactions,A1ME,1949,12:305-324.
- [17]罗瑞兰,程松林,朱华银,等.研究低渗气藏气体滑脱效应需注意的问题[J].天然气工业,2007,27(4):92-94.
- [18]Luffel D L,Hopkins C W,Schettler-Jr P D.Matrix permeabilitymeasurement of gas productive shales[R].SPE 26633,1993.
- [19]Daniel J,Soede R.Porosity and permeability of eastern devonian gas shale[R].SPE P116-124,1988.
- [20]Curtis J B.Fractured shale gas systems[J].AAPG Bulletin,2002,86(11):1921-1938.
- [21]Bazan L W,Larkin S D,Lattibeaudiere M G,et al.Improving production in the eagle lord shale with fracture modeling,increased conductivity and optimized stage and cluster spacing along the horizontal wellbore[R].SPE 138425,2010.