考虑应力敏感的致密气井压裂前后变泄气半径及产能研究

发布时间：2019-05-20 03:31

【摘要】：致密气井的泄气半径和产能会受到应力敏感和启动压力梯度的影响,利用边界压力梯度极限法,考虑应力敏感和启动压力梯度,建立了气井压裂前后的泄气半径及产能计算公式。通过实例验证了公式的准确性;同时分析了应力敏感、启动压力梯度、井底流压、裂缝长度对泄气半径和产能的影响。结果表明:泄气半径随井底流压、应力敏感系数、启动压力梯度的增加而降低;随裂缝长度的增加而增加,其中启动压力梯度的影响比应力敏感大。应力敏感对产能的影响大于启动压力梯度,变泄气半径下的产能随应力敏感系数的增加而降低,随裂缝长度的增加而增加;但产能变化幅度均小于定泄气半径。研究对致密气井泄气半径和产能的准确预测及提高采收率具有重要的意义。
[Abstract]:The discharge radius and productivity of tight gas wells are affected by stress sensitivity and start-up pressure gradient. the boundary pressure gradient limit method is used to consider stress sensitivity and start-up pressure gradient. The calculation formulas of gas discharge radius and productivity before and after fracturing are established. The accuracy of the formula is verified by an example, and the effects of stress sensitivity, starting pressure gradient, bottom hole flow pressure and fracture length on the discharge radius and productivity are analyzed. The results show that the discharge radius decreases with the increase of bottom hole flow pressure, stress sensitivity coefficient and starting pressure gradient, and increases with the increase of fracture length, in which the influence of starting pressure gradient is greater than that of stress sensitivity. The effect of stress sensitivity on productivity is greater than that of starting pressure gradient. the productivity decreases with the increase of stress sensitivity coefficient and increases with the increase of fracture length, but the variation range of productivity is smaller than that of fixed discharge radius. The study is of great significance for the accurate prediction of discharge radius and productivity of tight gas wells and the improvement of oil recovery.
【作者单位】：中国石油大学石油工程学院;
【基金】：国家油气重大专项(2011ZX05009-003)资助
【分类号】：TE328;TE37

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