Research On Seismic Response Characteristics Of Hot Dry Rock In Northern Anhui Based On Rock Physics

In order to reduce human dependence on fossil energy,alleviate environmental pollution,and achieve the goal of carbon neutrality as soon as possible,the task of developing new alternative energy sources is becoming more and more urgent.In order to cope with environmental problems and improve the energy utilization structure,people have continuously deepened their understanding of geothermal energy resources,and countries all over the world have focused their attention on the hot dry rock energy with great potential and environmentally friendly.Although the industry has used a variety of geophysical methods to explore hot dry rock resources,the relevant research mainly focuses on qualitative analysis.The physical properties of hot dry rocks under different temperature and pressure are relatively limited,and quantitative research cannot be done.which has caused certain difficulties in the effective development of hot dry rock resources.In this paper,based on the rock acoustic test,the wave velocity test and mineral composition analysis of different hot dry source rock(igneous rock)samples were carried out under laboratory conditions,Obtain information such as the mineral composition and porosity of the igneous rock,as well as the elastic parameters such as the P-wave velocity and S-wave velocity and dynamic elastic modulus of the sample under different axial pressure,confining pressure and temperature conditions.Through comparative analysis,it is found that the velocity,elastic modulus and other elastic parameters of igneous rocks are negatively correlated with temperature,but positively correlated with pressure.Combining the equivalent medium model,the calculation of pore fluid physical properties and Gassmann fluid substitution theory,the elastic parameters such as P-wave and S-wave velocity as well as elastic modulus of hot dry rock under temperature and pressure are calculated.The research results show that similar to the test results of igneous rocks,the elastic parameters of hot dry rock also have a certain negative correlation with temperature,a positive correlation with pressure,and its density has a certain positive correlation with pressure and a certain negative correlation with temperature.But its value is greater than the igneous rock test result.On this basis,based on the elastic wave theory,through the finite difference method,forward modeling the seismic profile corresponding to the two-dimensional model,analyze the seismic response characteristics of hot dry rock reservoirs under different temperature and pressure conditions,and compare its kinematics and dynamics laws,and guide the exploration of hot dry rocks in the study area by searching for sensitive attributes.In a word,this article systematically studies the rock physical characteristics and seismic response characteristics of hot dry rocks in northern Anhui by combining experimental testing,rock physical analysis and forward modeling of seismic profiles,which provides a basis for the effective development of hot dry rocks in northern Anhui.Theoretical guidance and key parameter support.