Abstract: Aiming at the geological characteristics of marine carbonate gas reservoirs in Qixia Formation in northwest Sichuan such as complex structure, ultra-deep burial, high temperature and high pressure, thin reservoirs and well-developed fractures, an embedded discrete fracture numerical simulator was prepared with ant tracking technology and embedded discrete fracture numerical simulation method on the basis of 3D seismic data to optimize the parameters of gas reservoir development and predict the development potential of gas reservoirs. The results showed that, it was more suitable to employ ant tracking technology to predict natural fractures in the early stage of gas reservoir development, and the embedded discrete fracture numerical simulator, compared with conventional reservoir simulators, had incomparable advantages in capturing the fluid that migrated in fractures, significantly improving the numerical simulation accuracy of fractured gas reservoirs; the development well type was optimized as highly deviated well and horizontal well for Qixia Formation gas reservoirs, the reasonable spacing between development wells was 1,600 to 1,800 m, the optimal length of horizontal well was 600 m, and the optimal half-length of artificial fracture was 100 m. There is much for reference of the study results for the efficient development of similar carbonate gas reservoirs.

Key words: northwestern Sichuan, Qixia Formation, carbonate rock, gas reservoir, fracture modeling, numerical simulation