大尺度串联双缝洞碳酸盐岩油藏的压力响应分析  

Pressure response analysis of large scale series double fracture-cavity carbonate reservoir

作　　者：熊钰[1] 叶海峰 蔡明金[2] 牛新年[2] Xiong Yu;Ye Haifeng;Cai Mingjin;Niu Xinnian(Southwest Petroleum University,Chengdu,Sichuan 610500,China;PetroChina Tarim Oilfield Company,Korla,Xinjiang 841000,China)

机构地区：[1]西南石油大学,四川成都610500 [2]中国石油塔里木油田分公司,新疆库尔勒841000

出　　处：《油气藏评价与开发》2018年第2期22-29,共8页Petroleum Reservoir Evaluation and Development

摘　　要：针对以裂缝—溶蚀洞穴为储集空间的大尺度非连续介质缝洞型油气藏,大量的井基本上都是独立的缝洞系统,多为通过井眼沟通大裂缝,然后由裂缝串联起1至2个大型溶蚀洞穴系统的独立缝—洞单元,采用连续介质理论解释所获得的结果难以和储层实际流动过程相对应。提出的数学模型把井—洞之间和洞与洞之间的裂缝考虑为一维裂缝,远井洞外围存在裂缝沟通流动,从而形成裂缝沟通两个溶蚀洞穴系统的线性串联试井数学模型,模型中引入了瞬态流动概念和多重介质中窜流的概念。利用瞬态传导原理和拉普拉斯变换逐步求解数学模型,在拉普拉斯空间下无因次井底压力的解析解进行改进的Stehfest数值反演绘制典型曲线,通过敏感性分析讨论发现该模型可正确反映流动控制因素与地质因素之间的关系。实例解释对比表明:用该模型可正确解释井筒储集系数、表皮效应、裂缝系统渗透率、溶洞系统等效渗透率、缝长和溶洞大小等几何参数。The fracture-cavity carbonate reservoir has large scale and discontinuous medium,and its main reservoir space is com-posed of fractures and caverns.Many wells are independent fractured-cavity systems,and most of them connect macrofractures to the wellbore.These wells are separate fracture-cavity cells which connect with one or two big cavities in series by fracture network,so the actual flow process of the reservoir does not match the result obtained by adopting traditional continuum theory.An analyti-cal mathematic model is presented by considering the fracture network between well-cavity and cavity-cavity as one dimensional linear fracture,and other fracture communication flow exist in the periphery of the cavity(away from wellbore).Accordingly,the linear-in-series well test mathematic model with fracture connecting two cavity systems is established,and the model introduces the conception of transient flow and channeling flow of multiple media.The Transient conduction principle and Laplace transform are used to solve the mathematical model,and the dimensionless bottom hole pressure type curves are plotted in real space by us-ing the improved Stehfest numerical inversion.The analysis of the sensitivity of cave parameters shows that the model can correctly reflect the relation between flow control factor and geological factor.Application examples indicate that this model can correctly ex-plain wellbore storage factor,skin effect,the permeability of fracture system and cavity system,and the geometric parameters of fracture and cavity.

关 键 词：缝洞型油藏 钻遇裂缝 双缝洞串联 数学模型 典型曲线分析 

分 类 号：TE372[石油与天然气工程—油气田开发工程]