Inland Basin Geothermal Exploration Lead To The Formation Deformation

The study on relation between interior sedimentary basin geothermal exploitation and land deformation will offer sicentical basis for geothermal resource evaluate and layout and for land deformation (land subsidence and fissure) forecast and control.The volume exchange relation portrays volume equation relations between land deformation and groundwater ultra picks quantity in unconsolidated aquifer-system. The paper has validated volumn exchange relation under steady load condition by simulation experiment. The experiment results indicate the volume exchange relation completely comes into existence. Therefore this theory can be used in interior sedimentary basin land deformation possibility analysis and forecast land deformation quantity (surface subsidence and crack quantity) induced by the in-depth underground fluid extraction simply and effectivly.The skeletal compressibility is that most important symbol to judge whether land deformation occurs. The key is to compute thermal reservoir elastic release quantity when the volume exchange relation equatoin is used in the research of relation between Xi'an geothermal exploitation and land deformation. The research data shows that Xi'an geothermal natural recharge is quite limited and the current exploitation quantity is largely from thermal reservoir elastic release quantity. Thermal reservoir elastic release quantity includes skeletal compressibility storage quantity and the pore-water expanding storage quantity. Therefore the skeletal compressibility storage quantity is equal to the difference of the current exploitation quantity and pore-water expanding storage quantity. The calculation confirmes the geothermal water extraction will lead to land derformation disaster. This paper forecasts that gross deformation quantity is 96×10~4m~3 every year and equal to subsidence whose rate is 2.06mm/a or as a crack whose length, width and depth is 10000m, 64mm and is 1000m respectively.