双重介质油藏压裂水平井非稳态压力动态分析

1)中国石油新疆油田公司工程技术研究院,新疆维吾尔自治区 克拉玛依 834000; 2)西南石油大学油气藏地质与开发工程国家重点实验室,成都 610500

双重介质油藏; 分段压裂水平井,体积源函数; 压力动态; Laplace变换; 正交变换

Unsteady pressure behavior analysis for fractured horizontal well in dual-porosity reservoir
Xie Bin1, Wang Junchao2, Huang Bo1, and Li Haitao2

Xie Bin1, Wang Junchao2, Huang Bo1, and Li Haitao2 1)Engineering Technology Research Institute, Xinjiang Oilfield Company of PetroChina, Karamay 834000, Xinjiang Uyghur Autonomous Region, P.R.China2)State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, P.R.China

dual-porosity reservoir; fractured horizontal well; volumetric source function; transient pressure behavior; Laplace transformation; orthogonal transformation

DOI: 10.3724/SP.J.1249.2015.03272

备注

针对双重介质油藏分段压裂水平井,首次采用体积源函数思想,建立在人工裂缝为均匀流量时非稳态压力动态模型.结合Laplace变换和正交变换,推导相应的体积源函数和无因次井底压力算法.根据体积源模型,在不同人工裂缝参数和储层参数下,绘制了分段压裂水平井压力动态曲线,分析了线性流动模型中水平井穿透储层对压力动态的影响.结果表明,水平井完全穿透储层的假设对早期和晚期的压力动态有明显影响; 人工裂缝条数和长度对压力动态的影响一直持续到边界效应的出现,且均存在一个最优的设计范围; 在裂缝条数相同的情况下,不同的裂缝分布方式也影响主要生产阶段的压力动态,因此,合理设计裂缝的分布方式对提高压裂水平井产能有重要意义.

This paper presents a new volumetric source model to analyze unsteady pressure behavior for fractured horizontal wells in dual-porosity reservoirs with uniform flux hydraulic fractures. By combining the Laplace transformation and orthogonal transformation, we derive the volumetric source function and the dimensionless well-bore pressure calculation method and draw the unsteady pressure curves for the fractured horizontal well according to parameters of hydraulic fracture and reservoir based on the volumetric source model. We also analyze the effect of the assumption of a horizontal well runs though the reservoir on pressure behavior in the tri-linear model. The results show that the assumption in the tri-linear model causes different pressure behaviors in the very beginning and later period of production. The number and length of hydraulic fractures have significant effects on pressure behavior before the appearance of boundary effect, and there is an optimal range for each of them. Meanwhile, the uneven spacing of hydraulic fractures affects pressure behavior during the main period of production. In other words, the design of rational distribution of hydraulic fractures plays an important role in increasing the output of fractured horizontal wells.

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