The sensitivity of the gas reservoirs in the Penglaizhen Formation of the Xinchang gas field, western Sichuan

It is very important to increase the recovery of low permeable gas reservoirs and reduce the degree of formation destruction. In shallower gas pools, the burial depth of pay zones is relatively shallow and formation pressure is also relatively low. The poor reservoir quality may easily result in the formation destruction during production. After being damaged, the productivity of a single well decreases sharply, or the well can't produce any natural gas at all. Numerous experimental studies of sensitivity suggest that the reservoirs in the shallow gas pools of the Penglaizhen Formation within the Xinchang gas field, western Sichuan are characterized by weak velocity sensitivity and moderate water sensitivity. The critical salinity values equal to (0.35-0.45)×10⁴ mg/L and critical pH values range between 7 and 8. The operation conditions are also proposed in the paper for the purpose of reducing different sensitivities.