复杂裂缝井的数值模拟的研究.pdfVIP

复杂裂缝井的数值模拟研究 王胡振 李鹏 刘振宇 （大庆石油学院黑龙江大庆 163318 ） 摘要：目前基于有限差分法对人工裂缝的数值模拟将裂缝处理成矩形缝，由于受到研究方法的限制，并没有对裂缝 进行更符合实际的合理描述，而有限单元法在人工裂缝的模拟方面体现出它的优势。本文应用有限单元法的基本原 理推导了油水两相渗流的有限元方程，并编制了有限单元法模拟器。通过与ECLIPSE 软件的计算结果进行对比，验 证了模型的正确性和准确性。应用油水两相渗流的有限模型，结合低渗透油藏的特点，对带有支裂缝的复杂人工裂 缝井进行了模拟研究。研究了不同支裂缝长度对油井产能的影响，并对模拟结果进行深入的分析，得出了有意义的 结论。 关键词：有限单元法；渗流；数值模拟；人工裂缝；低渗透 The numerical simulation study of complicated fractured well Abstract: In present, numerical simulation of artificial fracture based on finite difference method handle the fracture as rectangle fracture. The description of fracture was not consistent with the practical case restricted with research methods. Finite element method has lots of superiorities than finite difference method in numerical simulation of artificial fracture respect. In this thesis, basing on theory of finite element method the finite element flow equations were established, and a numerical simulator based on finite element method was made. Compare to the result of ECLIPSE software, the validity and accuracy of mathematical model was verified. Make use of oil-water two phases flow finite element model combined with the characteristic of low permeability reservoirs. The simulation study to complicated artificial fractured well of branched fracture has done. The study about the influence of branched fracture length to production performance was done, and the results were deeply analyzed. The result of simulation was significant. Key words: the finite element method, percolation, numerical simulation, artificial fracture, low-permeability 1 引言 目前研究油藏渗流问题的数值分析方法仍以传统的有限差分方法为主，特别是在流体力学领域 仍占支配地位。但用于几何形状复杂的问题时，它的精度将降低，甚至发生困难[1] 。有限单元法作 为一种有效的数值分析方法，在求解几何形状复杂的问题与有限差分法相比体现出它的优势。对于 人工压裂井，从目前的研究看，主要可分为两个方面的研究：一是研究人工压裂井的渗流规律，主 要研究在定产条件下井底的压力变化规律，进而研究人工裂缝特性，这方面已有大量的研究成果， 主要是应用解析法进行