非常规气藏产量递减模型特征与地质意义  

Characteristics and geological significance of production decline model of unconventional gas reservoir

作　　者：胥德平[1] 陈聆[1] 詹泽东[2] 刘露[2] 黄维婷[1] XU Deping;CHEN Ling;ZHAN Zedong;LIU Lu;HUANG Weiting(Key Laboratory of Geomathematics of Sichuan Province,Chengdu University of Technology,Chengdu 610059,China;Southwest Oil&Gas Company,SINOPEC,Chengdu 610041,China)

机构地区：[1]成都理工大学数学地质四川省重点实验室,成都610059 [2]中国石油化工股份有限公司西南油气分公司,成都610041

出　　处：《成都理工大学学报（自然科学版）》2023年第1期43-49,共7页Journal of Chengdu University of Technology: Science & Technology Edition

基　　金：国家自然科学基金项目(41774142)。

摘　　要：分析非常规气藏产量递减模型的特征,并探索其地质意义,为模型的优选与应用提供理论支撑。通过数理推导,结合气藏产量递减的有界性原则,从模型的极限、值域、单调性、极值性等方面针对目前常用的8类非常规气藏产量递减模型开展了系统研究,同时采用损失比,结合前人研究成果对模型进行了分类与地质意义研讨,并将不同模型应用于非常规气藏产量、累计产量预测。研究结果表明,(1)不同模型数学性质差异较大,总体上满足气藏产量递减有界性原则,但T.Ali提出的递减模型只能局部对气井产量和累计产量开展评价,其模型数学性质与气藏开发理论吻合性差;(2)按损失比的函数性质可以将不同产量递减模型分为三类,分别为幂律型、有理分式型以及复杂的非线性函数型,类比前人研究成果认为幂律型反映裂缝主导特性,有理分式型指示边界流特征;(3)不同模型在四川盆地气井产量预测效果存在差异,其中Duong模型、扩展指数模型、泛指数分布递减模型效果较好。将气藏产量递减模型特征与地质意义相结合,更有利于模型的优选与应用。The characteristics of the production decline model of unconventional gas reservoirs are analyzed and its geological significance is discussed in order to provide theoretical support for the optimization and application of the model.Through mathematical derivation and combining with the boundedness principle of gas reservoir production decline,eight kinds of production decline models commonly used in unconventional gas reservoirs are systematically studied from the aspects of limit,range,monotonicity and extremum.Meanwhile,loss ratio and previous research results are used to classify the models and discuss their geological significance,and different models are applied to forecast the production and cumulative production of unconventional gas reservoirs.The research results show that(1)the mathematical properties of different models are quite different,and generally meet the boundedness principle of gas reservoir production decline.However,the decline model proposed by T.Ali can only evaluate the production and cumulative production of gas wells locally,and the mathematical properties of the model are not in good agreement with the theory of gas reservoir development.(2)According to the function property of loss ratio,different production decline models can be divided into three types:power law type,rational fraction type and complex nonlinear function type.By comparing with previous research results,it is concluded that the power law type reflects the dominant characteristics of cracks,while the rational fraction type indicates the boundary flow characteristics.(3)Different models have different effects in predicting gas well production in Sichuan Basin,among which Duong model,extended exponential model and pan-exponential decline model have better effects.In general,combination of the characteristics of gas reservoir production decline model with geological significance is more beneficial to the optimization and application of the model.

关 键 词：非常规气藏 产量递减 产量预测 损失比 

分 类 号：TE328[石油与天然气工程—油气田开发工程]