摘要
水力压裂技术是成功实现干热岩资源开发利用的重要手段之一,数值模拟技术能够精准预测水力裂缝扩展。针对典型花岗岩,借助黏性单元法,分别模拟了致密花岗岩和天然裂缝存在情况下的水力裂缝扩展特征,得出以下结论:致密花岗岩的水力裂缝形态单一,天然裂缝的存在增加了压裂后裂缝的复杂性;致密花岗岩水力裂缝拓展主要分为憋压和拓展两个交替往复的阶段,当存在天然裂隙时,水力压裂过程会变得复杂;天然裂缝存在时,水力裂缝的缝长和缝宽分别为致密花岗岩的5.7倍和1.7倍;缝网的形成需要借助复杂的压裂工艺实现。研究结果可以为增强型地热系统(EGS)储层水力刺激工作提供理论支持。
Hydraulic fracturing technology is one of the most important technical means to successfully realize the exploitation and utilization of HDR resources.Numerical simulations can accurately predict hydraulic fracture propagation.Cohesive-zone-model was used to simulate the hydrofracture propagation characteristics of dense granite,and granite with natural fractures.The hydraulic fracture of dense granite is a simple crack.The existence of natural fractures increases the complexity of hydro-fractures.The hydrofracture development of tight granite can be divided into two phases:compression and expansion.Hydraulic fracturing can be complicated when natural fractures exist,and the length and width of hydraulic fractures are respectively 5.7 and 1.7 times those in dense granite.The formation of a complex fracture network needs special fracturing technology.These research results can provide theoretical support for hydraulic stimulation of an EGS reservoir.
作者
王璜
王贵玲
岳高凡
甘浩男
WANG Huang;WANG Guiling;YUE Gaofan;GAN Haonan(China University of Geosciences,Wuhan,430074;China Geological Survey,Beijing,100037;Institute of Hydrogeology and Environmental Geology,Chinese Academy of Geological Sciences,Shijiazhuang,050060;Technology Innovation Center of Geothermal&Hot Dry Rock Exploration and Development,Ministry of Natural Resources,Shijiazhuang,050060)
出处
《地质学报》
EI
CAS
CSCD
北大核心
2020年第7期2124-2130,共7页
Acta Geologica Sinica
基金
国家重点研发计划项目(编号2018YFB1501800)
国家自然科学基金青年基金项目(编号41807208)共同资助成果。
关键词
干热岩
花岗岩水力压裂
黏性单元模型
天然裂缝
数值模拟
enhanced geothermal systems
granite hydraulic fracturing
cohesive-zone-model
natural fractures
numerical simulation
