The pore throat of tight sandstone reservoir block is narrow

and during the whole process of gas reservoir development

the water phase trapping damage is easy to prone

which restrict the development process of tight gas. The field test and laboratory experimental study have proved that the heat treatment technology for reservoirs can remove this damage and increase the permeability

but it has not been popularized and applied because of the unclear reservoir physical properties. Therefore

typical tight sa

ndstone cores in Kuqa Depression

Huimin Depression and Jidong Depression are selected in order to simulate the fracture surface where heat treatment fracturing fluid stays or the near-wellbore zone where water phase gathers in the production process. A thermal shock experiment is carried out with 3 % KCL solution completely saturated experimental cores

the permeability of tight sandstone with different reservoir quality coefficient

RQI

before and after thermal shock is tested

and the relationship between the reservoir quality coefficient

RQI

and the increasing permeability is analyzed. The researches show that the permeability of tight sandstone samples does not change obviously when heated from room temperature to 100 ℃

but decreases slightly when heated to 200 ℃

and increases by 200 %~500 % when heated to 300~400 ℃

but the permeability of some samples does not change obviously

which is related to the reservoir quality coefficient

RQI

of the samples. The critical value of quality coefficient of water-bearing tight sandstone reservoir suitable for thermal surge permeability is 0.25. When

RQI

value is less than 0.25

the thermal surge permeability amplitude of rock samples is monotonically decreasing with

RQI

value. When

RQI

value is constant and heat shock temperature is greater than 200 ℃

the higher the temperature

the better the effect of thermal surge infiltration.