石油勘探与开发2017，Vol.44Issue(3)：439-445,7.DOI:10.11698/PED.2017.03.14
煤岩定向井水力裂缝起裂及非平面扩展实验
Experimental investigation on fracture initiation and non-planar propagation of hydraulic fractures in coal seams
摘要
Abstract
True tri-axial test system was deployed for fracturing simulation of coal outcrops to investigate the initiation and propagation of hydraulic fractures in vertical and directional wells.The influences of in-situ stress and cleats on non-planar propagation of hydraulic fractures in directional wells under different relative azimuths were analyzed.The test results show that the general propagation pattern of hydraulic fractures is jointly controlled by azimuth,cleats and in-situ stress.As the relative azimuth increases,the hydraulic fractures become more complicated in geometry and subject to increasing pumping pressure and propagation pressure.If the hydraulic fractures are initiated along a direction skewed with wellbore,the effect of cleats would alter the extension path and appear distortion of hydraulic fractures,inducing more complicated fracture geometry near the wellbore,with many fractures at the initiation point.Compared with vertical wells where I-shaped or X-shaped hydraulic fractures are formed,directional wells often have twisty propagation of dominant fractures near the wellbore and presence of multi-level fractures,which impede the further extension of hydraulic fractures in coal seams.关键词
煤岩/定向井/水力压裂/裂缝扩展/裂缝形态/非平面扩展Key words
coal seams/directional well/hydraulic fracturing/fracture propagation/fracture geometry/non-planar propagation分类
能源科技引用本文复制引用
谭鹏,金衍,侯冰,韩珂,周英操,孟尚志..煤岩定向井水力裂缝起裂及非平面扩展实验[J].石油勘探与开发,2017,44(3):439-445,7.基金项目
“十三五”国家科技重大专项基金(2016ZX05066) （2016ZX05066）
国家杰出青年科学基金(51325402) （51325402）
中国石油大学(北京)优秀青年教师基金(2462015YQ0203) （北京）
