Abstract:

X1 well, a great brine well in Central Sichuan, has become a commercial brine-gas well through about 30 years brine deviopment.Based on reservoir petrophysics and regional correlation, it is thought that the fracture system of the well is an independent sealing system with well developed subsurface fractures and has enriched abundant natural gas. The driving force of the well’s water and gas production is primarily resulted by elastic expansion of the gas on the water body and pore space contraction in the system. Depanding upon the production data and meterial balance theory, it has been calculated that there would be a great deal of gas in the system. The increase in gas production of the well would be more than that of water in future. It is proposed that"finding gas by water withdrawal"can be applied to the fractured reservoir in the compacted sandstone of the UPPer Triassic in Sichuan Basin.