水力喷砂射孔孔道形态研究

Research on channel pattern of hydraulic sand blasting perforation

为了进一步认识水力喷砂射孔机理,检测水力喷砂射孔成孔的形态和孔深,考察岩性、排量和喷射时间等参数对水力喷砂射孔的影响,了解裂缝起裂特征,开展了水力喷砂射孔孔道形态研究。完成了露头岩样靶件和水泥靶件的设计与制作,优选了实验参数和配套工具,并完成了喷砂射孔实验和喷砂射孔起裂实验。为了获得真实、直观的孔形结构,配套专用切割工具完成了靶件的解剖、测绘。实验结果表明,水力射孔形成的孔道深度远低于前期室内实验所得出的深度;水力喷砂射孔孔道形态主要为正常射孔靶件的准纺锤形喷孔和正常起裂的纺锤形—剑形组合喷孔两种形态;水力射孔形成的两个喷孔在形态上几乎对称;当靶件起裂后,喷孔深度成倍增加,同时起裂靶件不同方向上喷孔形态和深度不一样。

To further study the mechanism of hydraulic sand blasting perforation and examine the channel pattern and porous depth formed by hydraulic sand blasting perforation,a research on channel pattern of hydraulic sand blasting perforation has been carried out to observe the influence of lithology,displacement and blasting time on hydraulic sand blasting perforation and master the characteristics of fracture initiation.This paper has completed the design and manufacture of both outcrop core and cements targets,and optimized the experimental parameters and integrated tools,which were used to finish the hydraulic sand blasting perforation experiment and the fracture initiation experiment.In order to obtain more real and intuitive channel shape,the specific integrated tool has dissected and drawn the targets.These two experiments show that channels depth caused by hydraulic blasting is shallower than that induced by former laboratory experiment results.Two main channel forms resulting from hydraulic sand blasting perforation are fusiform-channel in the normal perforation target and built-up channel combing fusiform-channel with sword-channel.The two channel induced by hydraulic perforation almost symmetrical in shape.When the fracture is initiated,the depth will increase multiply.these conclusions are very reliable and helpful to further understand the mechanism of hydraulic sand blasting fracturing and improve and widespread this technology.