The Description Of Shale Gas Reservoirs

Shale gas resource potential is large and shale gas reservoir is a kind of unconventional natural gas reservoir with great commercial development values.The study target area is shale? block,which is a shale area of hilly and mountainous area in southern Sichuan.In this paper,the formation,sedimentary facies,structure,reservoir characteristics,gas-bearing characteristics and gas reservoir characteristics of the Longmaxi Formation at the block in southern Sichuan are described by using the seismic data,drilling data,logging data and various types of analytical laboratory data.Reserve of the target layer is calculated and evaluated.The calculation and evaluation of the reserves are carried out after establishing three-dimension shale gas reservoir geological model,which provides an important basis for the exploration and development as well as the effective utilization of shale gas.The gas-bearing shale section in the lower part of the Longmaxi Formation of the Lower Silurian Longmaxi Formation is the main target layer in this area.By studying the stratigraphic features,sedimentary facies,tectonic characteristics,reservoir characteristics,geochemical characteristics and gas-bearing characteristics,description of the study area is gas reservoir characteristics,shale gas reserves calculated by static method,target area 3d geological model is established,combined with the software parameters of analogy in alternative double calculation method for shale gas reserves,and on this basis,try to pattern design.The results showed that combined with the gas depth,flooding type,pressure coefficient and other factors to consider,the reservoir is determined to be one with medium depth,elastic air flooding,high pressure,dry gas,shale gas.And the reservoir is determined to be one with medium depth,high abundance,large size,medium pore,extra low permeability.Based on the study of reservoir heterogeneity with establishment of three-dimension geological model,from the point of view of permeability of the reservoir,the abundance of adsorbed gas,total abundance,gas saturation and so on,the shale reservoir homogeneity is good,longitudinal heterogeneity is serious.With the increase of formation depth,whether physical properties or gas content is better and better,and the 11 th floor is the main producer.Calculating The reserve that by the calculation of reservoir engineering method andthe reserve that by the calculation of three-dimension geological model,The error of reserve is2.02%.In summary,the gas reservoir is identified as the one with high abundance,large size,medium pore and low permeability.The well pattern is designed by geological model,which looks like the Chinese character ?.