Key Parameter Evaluation And Geological Modeling Research Of Shale Gas Reservoirs

Shale gas is a special natural resources, because of its abundant and widely distributed that attracted a lot of attention in the world. Shale gas research in many countries have made some progress. But now the shale gas research mainly focused on the influence factors for shale gas enrichment and shale gas accumulation.The evaluation system and evaluation standard of shale gas reservoir are not many, the study of shale gas reservoir geological modeling is rarely reported.In view of this,the paper analyzes the impact on shale gas scale and production capacity of twelve key evaluation parameters (organic matter, maturity, type of kerogen, effective thickness, reservoir property, silica content, gas content, pressure coefficient, water saturation, crack, specific surface and pore size distribution). Selecting the seven key evaluation parameters (organic carbon content, maturity, silica content, porosity, effective thickness, gas content, pressure coefficient), using the method of analytic hierarchy process (AHP) and the dispersion method to calculate the data of the five major shale gas field and Si Chuan shale gas field,then obtain the weight coefficient of each key evaluation parameters. Establishing a set of shale gas area evaluation system and establishing a set of shale reservoir evaluation standard which include seven key parameters data. Using the specific examples to verify the validity and rationality of the standard. If the shale gas area parameters data are not complete, then put forward different solutions depend on the data missing and set up different shale reservoir evaluation criteria. Finally,considering the complete and incomplete parameters data and establishing a set of shale gas area comprehensive evaluation standard.Shale gas area is relatively large, but the number of wells is not many. Establishing a geologcal model only rely on sedimentary characteristics and well's data may be different from the actual reservoir conditions. Therefore, using the variational function to conducted a number of analysis for the key parameters (porosity, free gas content, adsorbed gas content, total gas content), through the multiple simulations can get the actual geological conditions. Finally, using the deterministic modeling and the stochastic modeling to carry out relevent research for fracture modeling.