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断裂启动压力作为水泥糊补充强度的衡量标准
James A Frimpong1, Basel Ahmad Shabab1, Rohit Pandey1
1Mining and Minerals Engineering, Virginia Tech, 445 Old Turner St, Blacksburg, VA 24061 USA.
概括
这项研究引入了液压压裂法来测量水泥回填充 (CPB) 的拉伸强度,为传统测试提供了可靠的替代方案. 点应力模型准确地预测了CPB强度,考虑到钻井孔大小的影响.
科学领域:
- 地质技术工程 地质技术工程
- 材料科学 材料科学 材料科学
- 采矿工程 采矿工程 采矿工程
背景情况:
- 传统的方法来评估水泥回填充 (CPB) 的强度,如单轴压力强度 (UCS),巴西拉伸强度 (BTS) 和断裂性 (KIc),已经建立,但可能是劳动密集型.
- 在CPB中直接测量拉伸强度对于理解其机械行为和确保矿井稳定性至关重要.
- 现有的模型可能无法完全捕捉液压加压下CPB的复杂故障机制,特别是关于钻井孔几何.
研究的目的:
- 开发和验证液压压裂技术,直接测量CPB的抗拉强度.
- 为了确定断裂启动压力 (FIP) 和传统的CPB强度参数之间的相关性.
- 调查不同故障模型的适用性,包括点应力 (PS) 模型,从液压压裂数据中预测CPB拉伸强度.
主要方法:
- 在CPB样本上进行了实验室规模的液压压裂试验.
- 断裂启动压力 (FIP) 被记录为拉伸强度的主要指标.
- 通过回归分析将实验FIP值与UCS,BTS和KIc进行了比较.
- 应用了线性弹性故障模型和点应力 (PS) 模型来预测拉伸强度并分析钻井孔尺寸的影响.
主要成果:
- 在FIP和基准强度测量 (UCS,BTS,KIc) 之间观察到强烈的线性关系,验证了FIP作为CPB抗拉强度的可靠预测指标.
- 传统的线性弹性模型过度预测了CPB的拉伸强度.
- 点应力 (PS) 模型提供了更准确的拉力强度预测,并有效地解释了钻孔大小对液压加压响应的影响.
结论:
- 水力压裂,当使用点应力 (PS) 模型来解释时,是一种有效和实用的方法来确定水泥糊的拉伸强度.
- 这种技术为传统的强度测试方法提供了可行的替代方案,可能简化了CPB机械性质的评估.
- 该PS模型增强了在液压负载下CPB故障的理解,特别是与钻孔直径等几何因素相关.
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