浅埋深坚硬顶板定向钻孔水力压裂技术应用研究

Research on the Application of Shallow Buried Deep Hard Top Plate Directional Drilling Hydraulic Fracturing Technology

辛置矿为了解决了矿井坚硬顶板岩层高应力集中及冲击地压的难题,设计采用坚硬顶板定向水力压裂施工工艺,在辛置矿2-208工作面采用水力压裂技术进行压裂现场试验,并采用数值模拟对不同水力压裂参数进行研究。根据注液压力随时间的变化趋势,发现随着注液时间的不断增大,注液压力呈现先增大后减小的趋势,同时随着应力差逐步增大,此时注液压力峰值呈现降低的趋势。根据不同预制角下裂缝扩展长度变化曲线和不同注液排量下裂缝扩展长度变化曲线可知,随着预制角度的不断加大,此时裂缝长度呈现出逐步减小的趋势,而随着支注液量的增大,此时裂缝扩展长度呈现逐步增大的趋势。

In order to solve the problem of high stress concentration and rock burst in the hard roof rock layer of Xinzhi Mine,a directional hydraulic fracturing construction process with hard roof was designed.Hydraulic fracturing technology was used for on-site fracturing tests on the 2-208 working face of Xinzhi Mine,and numerical simulation was used to study different hydraulic fracturing parameters.According to the variation trend of injection pressure over time,it was found that as the injection time continued to increase,the injection pressure showed a trend of first increasing and then decreasing.At the same time,as the stress difference gradually increased,the peak injection pressure showed a decreasing trend.According to the variation curves of crack propagation length under different prefabrication angles and different injection rates,it can be seen that as the prefabrication angle continues to increase,the crack length shows a gradually decreasing trend,while as the injection amount increases,the crack propagation length shows a gradually increasing trend.