盐井—矿煤层水力压裂范围监测技术研究

1.重庆市能源投资集团科技有限责任公司,重庆 南岸 400060; 2.中国煤炭科工集团重庆研究院,重庆 九龙坡 400039; 3.重庆天弘矿业有限公司盐井一矿,重庆 合川 401519; 4.重庆市能源投资集团有限公司,重庆 渝北 401121

瞬变电磁法; 压裂范围监测; 煤矿井下; 水力压裂

Monitoring technology research on the scope of hydraulic fracturing effect of coal bed in Yanjing No.1 coal mine
ZHANG Cui-lan1,GUO Chen-ye1,XU Yang-cheng2,LIU Tao3,HE Hua4

(1.Chongqing Energy Investment Group Science and Technology Co.,Ltd.,Nanan 400060,China; .Chongqing Research Institute of China Coal Technology Engineering Group,Jiulongpo 400039,China; 3.Yanjing No.1 Coal Mining of Chongqing Tianhong Coal Mining Co.,Ltd.

transient electromagnetic method; scope of hydraulic fracture monitoring; coal mine underground; hydraulic fracturing

DOI: 10.13800/j.cnki.xakjdxxb.2014.0415

备注

根据瞬变电磁探测对低阻体反映灵敏的特点,采用瞬变电磁法在盐井一矿-150 m二石门进行了煤层水力压裂范围探测试验。选用本安型YCS-40瞬变电磁仪; 探测方式采用扇形方式,水平和垂直方向分别扫描50°,每10°一个测点; 为减少探测盲区,通过实验室和现场验证,将天线发射边长减为1 m,发射和接收天线匝数分别减为2匝、3匝,发射机频率设为75 Hz,发射电流限制为2.5 A,将压裂后的二次场转化为视电阻率。探测资料显示:有效探测范围为6~30 m,覆盖水力压裂范围; 能清楚的探测到压裂管道和两侧的积水区; 压裂水分布在水平向上0°~ 30°之间以及水平向上50°附近,压裂区域长度约为22 m,压裂区域宽度为5~12 m.因此,瞬变电磁物探仪能够有效探测水力压裂影响区域分布情况,探测结果与实际较为吻合,可以有效指导水力压裂现场施工,可为优化压裂设计、提高煤层压裂效果提供重要参考依据。

According to the characteristics of sensitive reflection when transient electromagnetic instrument detect to low resistance object,transient electromagnetic method is adopted to monitor the scope of hydraulic fracturing effect of coal bed in -150 m depth No.2 Crosscut of Yanjing No.1 coal mine for test.Intrinsically safe YCS-40 transient electromagnetic instrument is Chosen; Use fan-shaped detection method,scan 50° respectively on the horizontal and vertical directions,arrange a test point every 10°. In order to reduce detection blind area,by means of laboratory and field verification,reduce the antenna emission side length to 1m,reduced transmitting and receiving antenna number of turns respectively to 2 turns and 3 turns,transmitter frequency set to 75 Hz,emission current limit of 2.5 A,secondary field after fractured is converted to apparent resistivity.Detection data shows: effective detection range is 6 m to 30 m,covering the scope of hydraulic fracturing; the transient electromagnetic exploration instrument Can clearly detect fracturing on either side of the pipe and waterlogged area; Fracturing water distribute in the level up between 0° and 30° and level up near 50°,the fracturing area length is about 22 m,width of fracture area is 5~12 m.Therefore,the transient electromagnetic exploration instrument can effectively detect hydraulic fracturing affect regional distribution,detection results tally with the actual fracture distribution and detection,the result can effectively guide hydraulic fracturing site operation,can optimize coal seam fracturing design and provide important reference basis to improve the fracturing effect of coal seam.