电驱压裂设备在页岩气储层改造中的应用

压裂设备是页岩气藏储层改造的核心装备,随着国内页岩气勘探开发向深层进军,压裂工艺技术的发展对相关装备提出了更高的要求,而电力驱动则是压裂设备技术发展的重要方向。为此,调研了国内外电驱压裂设备的技术进展,指出大功率变频系统是决定其性能的一项关键技术,在分析该技术应用于电驱压裂设备适应性的基础上,结合2500型电驱压裂车在四川盆地威远地区实施页岩气储层改造压裂作业情况,对比分析了电力驱动压裂设备与柴油驱动压裂设备的相关经济技术指标。研究结果表明:①较之于相同功率的柴油动力压裂车,电驱压裂车可以实现功率全覆盖和输出排量的连续调节,能更好地满足压裂工艺对泵送排量精确控制的作业要求,同时还可以节省动力费用约68%、节约设备购置成本10%～20%;②较之于橇装设备,电驱压裂车具有更好的移运性能,适合在黄土沟壑、丘陵山地等道路条件较差的压裂井场推广应用。进而提出建议:下一步将提高单机功率密度作为电驱压裂设备的发展方向,同时加大高压大功率半导体器件的基础研究,提前做好页岩气平台建设的用电需求规划,以更好地发挥电驱设备的作业成本优势。

Application of electric drive fracturing equipment in shale gas reservoir stimulation

Fracturing equipment is the core device in shale gas reservoir stimulation. As domestic shale gas exploration and development steps into deep layers, the development of fracturing technology puts forward higher requirements for relevant equipment. Electric drive is an important development direction of fracturing equipment technology. In this paper, the technical progress of electric drive fracturing equipment in China and abroad was investigated. It is shown that a high-power frequency conversion system is the key technology to determine the performance of electric drive fracturing equipment. After the adaptability of the high-power frequency conversion technology to electric fracturing equipment was analyzed, based on the fracturing operation of Model 2500 electric drive fracturing trucks in the Weiyuan Block of the Sichuan Basin for shale gas reservoir stimulation, electric drive and diesel-driven fracturing equipments were comparatively analyzed from the aspects of economical and technical indicators. And the following research results were obtained. First, compared with a diesel-driven fracturing truck of the same power, an electric drive fracturing truck can realize a full power coverage and a continuous adjustment of output displacement, and can better meet the operation requirements of fracturing process for a precise control of the pumping displacement, while reducing the power cost by 68% and the equipment purchase cost by 10-20%. Second, compared with the skid mounted equipment, an electric drive fracturing truck has a better transport performance, being suitable for the fracturing well sites with poor road conditions, such as loess gullies, hills and mountains. It is suggested that the following development direction of the electric drive fracturing equipment should focus on the improvement of single machine power density. In addition, it is recommended to enhance the basic studies on high-pressure and high-power semiconductor devices and make a good plan for the power demand of shale gas platform construction in advance, so as to give a better play to the operating cost advantage of electric drive fracturing equipments.