| 摘要: |
| 采用大尺寸真三轴试验系统，对多裂缝储层水力裂缝与多裂缝干扰后影响水力裂缝走向的各种因素进行了研 究,并分析了压力曲线特征。试验结果表明:水平主应力差和逼近角是决定水力裂缝走向的主要因素，高水平应力 差和高逼近角有利于水力裂缝穿过多裂缝,水平主应力差越大,水力裂缝形态越平直;天然裂缝带发育程度和天然 裂缝面摩擦系数也是影响裂缝走向的主要因素,天然多裂缝越发育，越易造成压裂液大量滤失进而产生多水力裂 缝,摩擦系数越小,水力裂缝越易沿天然裂缝转向;天然多裂缝带的存在,会造成水力裂缝形态的非对称性;水力裂 缝的扩展具有非稳态特性。 |
| 关键词: 多裂缝储层 水力压裂 裂缝形态 裂缝扩展机理 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金项目(09510005);教育部“创新团队”项目(丨RT0411) |
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| Experiment of propagation mechanism of hydraulic fracture in multi-fracture reservoir |
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ZHOU Jian, CHEN Mian, JIN Yan, ZHANG Guang-qing
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(MOE Key Laboratory of Petroleum Engineering in China University of Petroleum, Beijing 1022A9 9 China)
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| Abstract: |
| Influences of all kinds of parameters on interaction between multiple natural fractures and hydraulic fractures were studied through a series of large-size tri-axial experiments, and the characteristics of pressure curves were analyzed. Test results show that the horizontal stress difference and approaching angle are main effecting factors on direction of hydraulic fractures propagation in multiple natural fractured reservoir. Crossing multiple fractures is easier for hydraulic fractures in the situation of high stress difference and high approaching angle. With the horizontal stress difference increasing, hydraulic fractures tend to be straighter. Growth parameters of multiple fractures and coefficient of interfacial friction are important effecting parameters, and multiple natural fractures lead to not only lots of leak-off of fracture fluid but also many branch fractures. Offset of hydraulic fractures can be easily caused by low friction coefficient. Non-symmetry of hydraulic fractures is caused by multiple natural fractures existing. Off-balance propagation of hydraulic fractures is confirmed in multi-fracture reservoir. |
| Key words: multi-fracture reservoir hydraulic fracturing fracture geometry fracture propagation mechanism |
