3-D Static Model To Characterize A Geothermal Reservoir In Neogene Guantao Formation In Bohai Bay Basin, China

Utilization of mid-deep geothermal resources is an important method which contributes to China’s carbon peaking and carbon neutrality goals. Bohai Bay basin is rich in mid-deep geothermal resources, the accumulative area of economically recoverable reserves of Guantao Formation in Huabei, Dagang, Jidong and Liaohe oilfields is 13348 km2, sandstone thermal reservoir is a key type which widely tapped. This paper taking the Caofeidian geothermal reservoir as modeling object, the sedimentary face of Neogene Guantao Formation is braided river, water salinity is between 1.1~2.8g/L, buried depth is between 1300~2700m, the cumulative heat storage thickness is between 150~300m, average porosity is between28~33%, and average permeability of sandstone is between 800~2000mD, reservoir temperature ranges from 70~110℃. Based on structural analysis，sequence stratigraphy analysis, sandstone thermal reservoir identification and characterization, we built 3-D static model of a geothermal filed in Neogene Guantao Formation in Caofeidian geothermal field by using “two step” method, at first we built structural model and applied zone division, then we built lithology, porosity, permeability, temperature models, and applied uncertainty analysis, these researches delineated the sandstone reservoir and laid the foundation of simulation and development plan of balanced production and injection in the same layer.