燃爆诱导酸化压裂在川西气井中的先导试验

Pilot test of blasting-acid fracturing complex technology in gas wells of western Sichuan

针对在川西深层致密气藏压裂过程中出现的破裂压力异常高、措施效果不明显、有效期短等问题,提出了燃爆诱导酸化压裂技术。为确定燃爆压裂合理火药量,通过理论分析建立了燃爆压裂设计中高加压速率下岩层破坏强度分析模型和非均匀地应力条件下套管极限抗内压计算模型,并对川高561井进行了燃爆诱导酸化压裂的方案设计和现场试验。结果表明:燃爆诱导压裂可有效降低地层破裂压力,酸预处理可进一步改善近井地带渗流通道;燃爆诱导酸化压裂复合技术可有效解决深层致密气藏无法压裂投产的问题,并能大幅度提高此类气藏的单井产能。

Aimed to the problems of the abnormal high fracturing pressure, un-conspicuous operating measures effect and the short valid date during the fracturing process of deep compacted gas reservoirs in western Sichuan, blasting-acid fracturing complex technology was proposed. In order to determine the reasonable propellant charge, the rock failure strength model under the dynamic loading and the in-casing limiting load model in the non-uniform ground stress field were established by the theoretical analysis to the process of the blasting fracturing. The fracturing program for well Chuangao 561 was designed and the field testing was curried out. The results show that the reservoir fracturing pressure can be reduced by the blasting fracturing, and the preamibility near wellbore is improved. The blasting-acid fracturing complex technology can effectively solve the problem of fracturing and putting into production of the deep compacted gas reservoir, and the well productivity is greatly improved.