Hydro-jetting and Staged-fracturing Technique with Original Production String Applied in Deep Gas Reservoir

As a low-porosity,low-permeability,and tight sandstone gas reservoir,Xujiahe 4 Member of western Sichuan Basin is featured by deep burial depth,high pressure,and high fracturing and extension pressure.So it is difficult to carry out a fracturing.During the completion of liner tube in horizontal section of X21-2H well,combining with hydraulic-jetting and sliding-sleeve multi-layer fracturing,this study develops another hydraulic-jetting and staged-fracturing of original production string.Multi-staged fracturing has been realized by sand blasting perforation and fracturing after opening sliding-sleeve.By optimizing the nozzle number,in-well string and the injection volume of tools and tubing-casing,adopting over-crosslinking fracturing fluid and annular pressure control,this fracturing ensures a smooth construction and succeeds in deep and tight gas reservoir with high pressure.