An evaluation method for aggregate index G

i

of drilling and logging is proposed based on a calculation of weight coefficients for all parameters gathered during drilling and logging.The drilling and logging parameters as well as capacity building of gas wells in the gas pools in western Sichuan Basin are analyzed.For the gas well targeted at the reservoirs in the Penglaizheng and Shaximiao formations in XC gas field

industrial gas flow is highly possible to be achieved after fracture treatment when the Gi are larger than 6.0 and 12.5 respectively.The method is also proved effective in guiding layer selection during workover and stimulation of old wells

with a success rate of more than 70%.