摘要
针对煤矿井下作业空间小,供电供水能力有限,地面加砂压裂装备无法直接应用于煤矿井下的现状,提出了高压端加砂压裂的技术思路。基于液动冲击混携砂原理,研发了高压端连续水力加砂压裂装备。该装备不需要外部动力源进行混砂,而是通过压裂液流态和流场的变化形成旋流冲击实现混砂和携砂。理论分析、数值模拟和室内仿真试验均表明,该装备在原理上是可行性的,能够有效混砂和携砂。研发的装备整体耐压达到55 MPa,一次可装石英砂750 kg,可实现单个或者多个穿层钻孔的连续加砂压裂。配套设计了三通道并联的煤矿井下高压端连续水力加砂压裂控制系统,该系统通过矿用压风实现开关的开合,与压裂泵的控制系统协同对加砂过程实现远程集中控制,确保加砂过程安全可靠。运用该装备在安徽淮南矿区潘三煤矿进行了5个底板穿层钻孔的现场试验。结果表明:该装备携砂能力较强,仅需开启通道二即可实现有效加砂,最大连续加砂量150 kg,最大注水量316 m^(3),加砂压裂钻孔瓦斯抽采纯量、百孔瓦斯抽采量分别是清水压裂钻孔的2.38和2.03倍,增透效果明显。研发的装备可应用于煤矿井下高压水射流、水力切割以及水力加砂压裂等领域。
The technological concept of sand fracturing at the high pressure side is proposed against the present situation where the coal mine downhole operation space is small,the power and water supply capacities are limited,and the surface sand fracturing equipment cannot be applied directly in the coal mine downhole.On the basis of the principle of sand mixing and carrying through hydrodynamic impact,the continuous hydraulic sand fracturing equipment at the high pressure side was developed.Such equipment requires no external power source for sand mixing.It forms cyclone impact through the changes in the flow regime and flow field of the fracturing fluid to realize sand mixing and carrying.As indicated by the theoretical analysis,numerical simulation and indoor simulation test,this equipment is feasible in principles,and can effectively mix and carry sand.The developed equipment has the overall pressure resistance of 55 MPa,750 kg quartz sand can be loaded at one time,and can realize the continuous sand fracturing for a single crossing borehole or multiple crossing boreholes.The associated 3-channel shunt continuous hydraulic sand fracturing control system at the high pressure side of the coal mine downhole was designed.This system uses the mine compressed air to realize the on/off action of the switch,and coordinates with the fracturing pump control system to realize the remote concentrated control over the sand adding process,so as to ensure the safety and reliability during sand adding.The equipment was applied to carry out the field test for 5 floor crossing boreholes at the Pansan Coal Mine in Huainan Mining Area,Anhui.As indicated by the results,this equipment has high sand carrying capacity,and effective sand adding can be real-ized by only opening Channel II,with the maximum continuous sand adding amount of 150 kg and the maximum injec-ted water amount of 316 m^(3).The gas extraction scalar quantity of the sand fracturing borehole and the gas extraction quantity of the 100 m borehole were 2.38 and 2.03 times of that of the water fracturing borehole,respectively,showing significant effects in permeability enhancement.The developed equipment can be applied in the fields,such as the coal mine downhole highpressure water jetting,hydraulic cutting and hydraulic sand fracturing.
作者
贾秉义
李树刚
陈冬冬
林海飞
郑凯歌
孙四清
赵继展
JIA Bingyi;LI Shugang;CHEN Dongdong;LIN Haifei;ZHENG Kaige;SUN Siqing;ZHAO Jizhan(Xi’an Research Institute Co.Ltd.,China Coal Technology and Engineering Group Corp.,Xi’an 710077,China;College of Safety Science and Engineering,Xi’an University of Science and Technology,Xi’an 710054,China)
出处
《煤田地质与勘探》
CAS
CSCD
北大核心
2022年第8期54-61,共8页
Coal Geology & Exploration
基金
国家自然科学基金面上项目(51874236)
中煤科工集团西安研究院有限公司科技创新基金项目(2021XAYJSQ07)。
关键词
高压端
水力加砂压裂
瓦斯抽采
淮南潘三煤矿
煤矿井下
high pressure side
hydraulic sand fracturing
gas extraction
Pansan Coal Mine in Huainan
underground coal mine
