Study On The Geophysical Response Characteristics Of Three Natural Gases Co-Exploration Reserviors In Coal Measures

According to the latest statistics of oil and gas resources,China is rich in unconventional natural gas and has great potential for development.Compared with conventional oil and gas,the unconventional gas of coal measures has different geophysical response characteristics.Seismic prediction technology for conventional oil and gas reservoirs can not be well applied to the prediction of unconventional gas reservoirs in coal measures.In order to effectively predict the "three gas" reservoirs and gas bearing capacity of coal measures,we also need to reduce exploration costs,improve gas reservoir development efficiency and resource recovery.On the basis of rock physical testing and analysis of the "three gas" reservoir in coal measures,this paper provides a technique for predicting the thickness of coal bed gas,shale gas and tight sandstone gas reservoir and the prediction of gas rich area by using a bridge between seismic and logging to identify the "three gas" of coal measures,based on the characteristics of log response.Theory.The petrophysical test and analysis of coal rock samples show that the empirical formula of coal rock velocity and density is very different from that of sandstone.The permeability of rock sample is exponentiation with porosity,and the permeability increases with the increase of porosity,and the elastic parameters can identify whether gas is contained.The study of logging response characteristics can distinguish the lithology and physical property through the analysis of different parameters.At the same time,the reservoir gas content can be calculated by the multiple regression method and so on,and the horizon calibration can be carried out in combination with the seismic forward modeling.Prestack seismic inversion can directly predict the distribution of gas bearing reservoirs.