| 摘要: |
| 在拟稳态流动阶段,边界封闭效应会对气井产能计算及优化产生很大影响。以单条人工裂缝为研究单元,在推导有限导流因子基础上,利用积分变换、渐近分析等方法获得单裂缝拟稳态压力基本解,基于势叠加原理、物质平衡方程建立矩形地层有限导流压裂水平井产能计算模型并迭代求解,同时回归产能关于压裂参数的导数极大值获得最优参数的函数关系线。结果表明:气井产能受裂缝条数、长度、间距、导流能力、相对位置及气藏几何形状等因素影响,增大裂缝与地层接触面积、减小缝间干扰、降低边界封闭效应、平衡裂缝与地层流入流出关系能有效提高气井产能;当裂缝系统均分气藏泄流面积时裂缝布局最优,而对应的裂缝最优导流能力关系线则随气藏矩形长宽比、裂缝条数的变化而变化;在最优参数作用下气井能较为显著地达到较高的产能水平,实际使用时应选取最优参数线附近区域作为优化压裂参数的参考范围。 |
| 关键词: 水平井 有限导流 拟稳态 无量纲产能系数 参数优化 |
| DOI：10.3969/j.issn.1673-5005.2016.01.014 |
| 分类号::TE 312 |
| 基金项目:国家科技重大专项(2011ZX05015) |
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| Pseudo steady productivity evaluation and optimization for horizontal well with multiple finite conductivity fractures in gas reservoirs |
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WANG Junlei, JIA Ailin, WEI Yunsheng, ZHAO Wenqi
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(PetroChina Research Institute of Petroleum Exploration ＆ Development, Beijing 100083, China)
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| Abstract: |
| The fracture boundary with no flowing through has a significant influence on productivity evaluation and fracturing parameter optimization in a pseudo steady state (PSS). In this paper, the solution of pressure distribution in the PSS in a single hydraulic fracture with finite conductivity was derived incorporating an integral transformation method, and a novel productivity model of a multiple fractured horizontal well (MFHW) within rectangular formation was presented in coupling with material balance equation and pressure superposition. The model was solved using a Newton numerical iteration method. The model was used to calculate the productivity of a MFHW with regard to different fracturing parameters, and the corresponding optimum relationships were established by regressing the maximum derivatives of productivity with different fracturing parameters. The results show that the productivity of a MFHW is determined by the number of fractured sections, the spacing, length, conductivity and configuration of the fracture. The productivity can be enhanced via stimulating more fractures, reducing the interaction between fractures, restraining the no flow effect of fracture boundaries, and matching the inflow rate with that of the outflow rate of the fractures. The configuration of equally spaced multiple fractures is the optimal condition for fracture arrangement, and the optimum relation of dimensionless conductivity varies with the changes of length-width ratio and the fracture number. In practical application, a narrow parameter range around the optimum values should be selected as a reference for optimizing the fracturing parameters. |
| Key words: horizontal well finite conductivity pseudo steady state dimensionless productivity index parameter optimization |
