Research On Distubution And Controlling Factors Of Ordovician Geothermal Resources In Tianjin

For the petrographic features of Ordovician carbonate in the research area,research and discussion were conducted in the stratigraphic division and correlation,geothermal reservoir characteristics,geothermal temperature field characteristics,karst fissures law and influencing factors,Reservoir characteristics and evolution,controlling factors and distribution of reservoir,and so on.The main conclusions are as follows:1.On the basis of comprehensive analysis of theOrdovician stratigraphic division in the past,it analyzed the stratigraphic of the research area and discussed the rock electrical characteristics of each group.Ordovician stratigraphic in the research area was mainly divided into:Lower Ordovician into Yeli Group and Liangjiashan Group;Middle Ordovician into Lower Majiagou Group,Upper Majiagou Group and Fengfeng Group;Upper Ordovician was missing.2.Tianjin which located in the northeast of the North China basin,is Mesozoic an Cenozoic rift basin.In the deep,heat conductionwas heat transfer.In the shallow,the fluid migration accelerated the transfer of local heat due to the fractures.According to plane distribution and vertical variation,the main factors influencing geothermal temperature field distribution were fracture fractures,stratigraphic lithology and magmatic activities.3.Based on analyzing geothermal well data which drilled Ordovicianin different tectonic units of Tianjin,statistics total thickness of one and two types of cracks in Ordovician geothermal reservoir.Research the distribution and controlling factors of Ordovician geothermal resources,by the Karst cracks thickness respectively related with depth and thickness of rock roof and the different strata overlying Ordovician,distance from cracks to the top and bottom of Ordovician,water inflow of Ordovician geothermal well,dropout situation,distance from dropout pitch to Ordovician roof and floor,and so on.Researches showed that Karst fissures were mainly influenced by lithology,geological structure and geothermal fluid runoff strength.4.It preliminary identified the distribution and controlling factors of Ordovician geothermal resources,through analysis on transformation of regional tectonic movement,evolution of depositional environment and Carbonate diagenesis,cracks,faults and Karstification.