Experimental Study On The Thermophysical Properties Of Organic-rich Shales

The parameters of rock thermophysical properties include thermal conductivity,specific heat capacity,thermal diffusivity and thermal expansion coefficient.In this paper,experimental tests of thermophysical properties of various types of shale are studied to find the influencing factors of thermophysical properties and the changing rules.This experiment lays a foundation for temperature prediction in shale reservoir fracturing process and paves the way for new special mining technology.In this study,Yaojie oil shale,Jilin shale,Qianjiang shale,Longmaxi shale and Lujiaping shale are selected as the main sample.At the same time,unconventional reservoirs such as Jilin tight gas,Yanchang tight sandstone,Changqing tight sandstone and high purity single mineral artificial rock samples are compared and tested.Quickline TM 30 and Hot Disk instruments were used to test the thermophysical properties of rock samples at room temperature and pressure.At the same time,taking Longmaxi Formation shale and Lujiaping Formation shale as the research objects,the influencing factors and changing rules of the thermophysical properties of shale are studied and analyzed.The thermophysical property model of shale is established by mixing theory.It is found that the mineral composition of rocks determines the thermal physical properties of rocks,and the influence of different minerals on the thermal physical properties of shales is different;The thermal conductivity and specific heat capacity of shales are inversely proportional to porosity and permeability,but the correlation coefficient of shales is worse than that of sandstones,which is related to the compactness of shales;The TOC content is inversely proportional to the thermal conductivity of rocks;There are obvious differences in thermophysical properties between vertical and parallel bedding directions,which are consistent with acoustic anisotropy;thermal conductivity,The thermal conductivity,thermal diffusivity and temperature are inversely proportional,and the specific heat capacity and temperature are proportional.The original water saturation has little effect on the thermophysical properties of shale.A mathematical model based on three-dimensional space is established to fit the thermophysical properties of reservoirs.Using MATLAB to calculate iteratively,the fitting matrix can be obtained,then the thermophysical properties of reservoirs can be calculated,and the simulated three-dimensional physical model can also be obtained.