东振;刘亚东;鲍清英;张义;陈姗姗;

• 1:中国石油勘探开发研究院廊坊分院

• 2:中国矿业大学资源与地球科学学院

摘要(Abstract)：

为了提高煤层气井破裂压力预测精度,运用断裂力学理论推导裂缝性地层破裂压力计算公式,结合分形岩石力学理论建立裂缝性地层破裂压力解析模型,提出一种实用的破裂压力计算方法.结果表明:在非均匀地应力下,煤岩井壁更易沿最大水平主应力方向起裂,解析模型与传统模型在表达形式上具有统一性和更广泛的适用性.煤岩裂缝具有分形特征,分形效应提高岩石阻碍裂缝扩展的能力,当分形维数越大、相似比越小时破裂压力越大.在不同裂缝状态下,缝长对破裂压力的影响规律不同,当裂缝长度较小时破裂压力随裂缝长度增加而迅速减小;当裂缝长度增加到一定数值后,闭合裂缝破裂压力随缝长增加而增大,开启裂缝破裂压力随缝长增加而减小并趋于定值.郑庄地区5口煤层气井实例计算表明:该计算方法预测的破裂压力误差在10%以内,破裂压力对缝长变化特别敏感,合理确定裂缝长度对准确预测破裂压力尤为重要.

关键词(KeyWords)：破裂压力;断裂力学;分形几何;有限元;煤层气

Abstract:

Keywords:

基金项目(Foundation):国家科技重大专项(2011ZX05033,2011ZX05033-001,2011ZX05043-006)

作者(Author):东振;刘亚东;鲍清英;张义;陈姗姗;

Email:

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