3D Geological Modeling Of WCM Coal Seam Group In Surat Block

Coalbed methane(CBM),commonly known as coal seam methane or coal seam gas,is a kind of combustible gas generated by organic matter in the process of coalification,which mainly exists in the coal seam and its surrounding rock in adsorption state.Its main components are methane,followed by carbon dioxide,nitrogen,etc.Coalbed methane is a kind of natural gas resource of self generation and self storage.Compared with conventional oil and gas resources,it is quite different in geological characteristics,genetic evolution,storage mode and other aspects,so it is called unconventional natural gas.As a new clean and economic energy,the utilization and development of coalbed methane is of great significance to alleviate the global energy tension,reduce the greenhouse gas emissions,fundamentally reduce the occurrence of coal mine accidents,and develop coalbed safely and effectively..The exploration and development of coalbed methane is of great significance to the energy development of China.It is of great significance to study the characteristics of coal seam and its physical parameters and to establish a three-dimensional geological model for the prediction of favorable coal reservoirs and their efficient development in coalbed methane.This paper focuses on the WCM coal seam group of Surat block in Surat basin,Australia.Combined with the geological,logging,laboratory analysis and test data of the basin,and under the guidance of petroleum geology,logging data processing and interpretation,coalfield geology and other disciplines,the geological model of Surat block is established.First of all,the coal seam classification and correlation of single coal seam level are completed according to the sequence of large layer group,small layer group and single coal seam by means of marker bed correlation,lithofacies cycle correlation and other methods.On the basis of preprocessing the logging curve and combining with the logging response characteristics of the coal seam to determine the density cut-off value,the logging interpretation of coalbed methane in the study area is completed.Based on the core analysis data of coal seam,the quantitative analysis of physical parameters of coal reservoir is completed,and the influencing factors and internal relations of key parameters are summarized.The structural model is established by using the layer trend surface of logging stratification results and seismic interpretation,the attribute models such as density model,gas content model and ash model are established by using the results of coal reservoir physical parameters analysis to analyze the spatial characteristics of reservoir physical properties;the geological reserves in the study area are calculated by volume method.The main control factors affecting peak production are analyzed and the cut-off values of permeability and dry ash free gas content in favorable areas are determined.Five potential areas are predicted.