岩溶热储古岩溶发育机制与地热水富集模式OACSTPCD

Understanding the mechanisms underlying ancient karst development,the evolution of formations,and character-istics of karst reservoirs holds immense significance in unveiling the occurrence patterns and enrichment principles of geother-mal resources.Using the northern Jinan geothermal field as a case study,the research focuses on elucidating the sequence stratigraphy and sedimentary facies characteristics of the Ordovician Majiagou Group carbonate rocks.It formulates the paleo-karstification types and the mechanisms governing karst geothermal reservoirs by analyzing the spatial development character-istics of surface and underground karstification,revealed through bore holes,and the distribution of the water-rich areas un-covered by geothermal wells.The evolution of karst in the northern Jinan geothermal field follows a specific process:The three-stage karst development involving contemporaneous karst,paleo-weathering crust karst,and buried karst influences lay-er distribution and regional karst development,particularly interlayered karst.The intensity of karst development is governed by structural karst.The depth of eothermal water circulation and karst development is influenced by gravitational potential.Furthermore,the model depicting strong karst development and geothermal water enrichment in the northern Jinan geothermal field is as follows:Within a depth range of 320 meters below the Ordovician roof,the strongly developed karstification zone and the geothermal water enrichment zone occur either within the compound zone consisting of interlayered karst and structur-al karst,or at the contact zone between the interlayered karst and intrusive rock masses.