Interpretation Method Of DST Temperature Data For Low Permeability Reservoir In Xihu Depression

On the oil and gas reservoir test,the bottom hole pressure and temperature dynamic data are usually tested synchronously.The interpretation method of pressure data has been very mature,and it is one of the important means for reservoir evaluation in oil and gas field development.There are few developments about the interpretation method of bottom hole temperature data is all over the world,which reduces the utilization of test data and causes a waste of manpower and material resources.In fact,the temperature test data also has a high application value.On the one hand,the temperature dynamic data has high accurracy.On the other hand,in some reservoirs with complex seepage laws,such as low-permeability reservoirs,it is often difficult to get the effective pressure data.Under these circumstances,the interpretation of temperature data can be used as a method to acquire the reservoir dynamic parameters.Moreover,the propagation of underground pressure is also affected by the temperature,so it is not accurate to use the pressure test interpretation model considerring the seepage field alone.Based on the previous studies,this paper has carried out the following research on the interpretation method of low permeability reservoir temperature test data: Firstly,based on the full study of the seepage characteristics in the low permeability reservoir and the heat transfer law of the porous medium,consideration the interaction of seepage field and temperature field in the stratum comprehensively,the mathematical model of heat flow of low-permeability reservoir and low-permeability gas reservoir is established according to the law of conservation of mass,conservation of momentum and conservation of energy.Then the method of double iteration is used to solve the mathematical model.The mathematical model of heat flow in low permeability reservoirs is numerically solved.Then,the dynamic characteristics of temperature and pressure in the bottom hole is calculated and the sensitivity of its parameters are analyzed under the condition of heat transfer and speepage coupling.Finally,according to the result calculated,the bottom-hole temperature dynamic curve is fitted with the tested bottom temperature data of the low-permeability reservoir in the Xihu Depression,and the thermodynamic parameters of the reservoir are reversed.According to the difference of the thermodynamic parameters of oil,gas and water in the rock reservoir,the saturation in the reservoir can be calculated.The results of this research show that the temperature field in the reservoir is constantly changing during the production process of the oil and gas well.The change of the bottom temperature of the oil and gas well is affected by the thermodynamic parameters of the fluid and rock in the reservoir.According to the tested data of the bottom hole temperature.the comprehensive thermodynamic parameters of the stratum can be inversely determined,and the formation saturation can be reversed according to the difference of thermodynamic parameters of each phase in the reservoir.