摘要
基于对三维空间下水力裂缝尖端应力场以及作用在天然裂缝面上的应力场的分析,建立了水力裂缝穿透天然裂缝的判别准则。利用大尺寸真三轴水力压裂实验模拟系统,实验研究了不同产状天然裂缝、地应力对水力裂缝扩展行为的影响。实验研究表明:水力裂缝穿透预制裂缝的现象主要发生在高逼近角、高走向角、高水平应力差异系数、高水平应力差的区域;水平应力差存在一个临界值,大于该值,水力裂缝才可能穿透预制裂缝。实验结果与本准则预测结果吻合良好。应用本准则,预测四川盆地龙马溪组页岩气试验井水力裂缝不能穿透天然裂缝面,与微地震压裂监测解释结果一致。
Based on the analysis of the stress fields near the hydraulic fracture tip and on the natural fracture surface, a criterion for identifying hydraulic fractures crossing natural fractures was proposed. A series of hydraulic fracturing tests were conducted to investigate the influences of natural fractures occurrence and horizontal stress contrast on hydraulic fracture propagation using large scale tri-axial fracturing system. The experiment results showed that the crossing happens in the region with high approaching angle and strike angle, large horizontal stresses and horizontal stress difference coefficient. Horizontal stress contrast has a critical value, only when it is above the critical value, may the hydraulic fracture cross the natural fracture. These experimental results agree with the predictions of this criterion well. It is predicted by this criterion that the hydraulic fracture of a test well in the Longmaxi shale formation, Sichuan Basin, can’t cross the natural fracture, which agrees with the micro-seismic monitoring results.
出处
《石油勘探与开发》
SCIE
EI
CAS
CSCD
北大核心
2014年第3期336-340,共5页
Petroleum Exploration and Development
基金
国家自然科学基金项目(51174217
51234006)
关键词
页岩
水力压裂
天然裂缝
水力裂缝
产状
shale
hydraulic fracturing
natural fracture
hydraulic fracture
occurrence
