Analysis Of Middle And Shallow Geothermal Field Characteristics And Influencing Factors In Changling Sag In Southern Songliao Basin

In recent years,oil and gas exploration shows that the middle and shallow layers of Changling depression in the southern part of Songliao Basin not only contain rich oil and gas resources,but also have a good prospect of geothermal resource exploration.The study on the characteristics of geothermal field can lay a good foundation for geothermal resource exploration in the future.Based on the systematic analysis of previous research results,53core samples in the study area(Quantou Group,Qingshankou Group,Yao Group,Nenjiang Group),collected to test thermal conductivity,specific heat capacity and thermogenic rate;combined with porosity,permeability and mineral composition analysis,the influence factors and rock thermal property parameters,and the geothermal field evaluation;and the main control factors of geothermal field are analyzed from seven aspects:structural evolution,fault system and volcanic activity.studies have shown,The average thermal conductivity of the shallow rock in Changling depression is 2.11W/(m·K),The thermogenic rate averaged 1.19μW/m3,The average specific heat capacity is 1.83 MJ/(m~3·K);The thermal property parameters have a certain correlation with the porosity,permeability and rock-mineral composition;The study area has a very high geothermal field,The mean value of the geothermal gradient was 3.96℃/100m,The mean earth heat flow value is 80 m W/m~2,On the plane of the geothermal field,there are the characteristics of low middle,high north and south sides,and the whole ring distribution;Mantle heat source and yingcheng Formation igneous rock are the most fundamental geothermal source of Changling sag;Deep and large fracture and base fluctuation are the core influencing factors of the geothermal field of Changling depression;The research area has good prospects for geothermal resources exploration.