Fracturing treatment technology in the Carboniferous volcanic formations in the Kelameili Gas Field

The stimulation of Carboniferous volcanic formation in the Kelameili Gas Field, Junggar Basin, is one of most important means of enhancing the growth of reserves and production and making good evaluation on its deliverability. However, micro-cracks with poor connectivity in the supermature formation after fracturing treatment are inclined to form complex fractures, including turning fractures, fish bone crackles, multiple fractures in the different or same azimuths, vertical multiple fractures, etc. For this pur-pose, the diagnosis methods of complex fractures including near wellbore effect analysis, fracturing treatment analysis, and post-frac pressure analysis, are used to make a comparative analysis of ten wells. The results show that there are no large branch of fracturing cracks resulted from fracturing among them while there are bending cracks in all of them, among which 50 percent belong to slight bending,20 percent moderate bending,and 30 percent severe bending. That is, the elementary rule found is that the fracturing treatment of Carboniferous volcanic formation generally leads to, instead of large branch cracks, cracks bending to various degrees. This will provide foundations for the prevention and control of complex fractures and help increase the effect of fracturing treatment.