Distribution of Coal Measures Water in Fanzhuang Block of Qinshui Basin and Its Impact on Drainage Effect
The Fanzhuang block is one of the typical representative blocks of high coal rank coalbed gas fields.Fine characterization of the distribution characteristics of coal measures water and analysis of its gas control effect are of great significance for guiding the development of coalbed methane in similar blocks.Based on this,mathematical statistics,regression analysis,and data fitting methods were used to establish the logging identification characteristics of coal seams and sandstones,construct a water content calculation model,and explore the relationship between the distribution of coal bearing water and the drainage effect.Research has shown that the logging identification characteristics of the 3#coal seam in the study area are high resistivity(853.86～5 968.9Ω·m),low bulk density(1.26～1.49 g/cm3),and low natural gamma(18.4～60.51API).The logging identification characteristics of sandstone aquifers are low resistivity(70～316.2Ω·m),high bulk density(2.51～2.68g/cm3),and low natural gamma(56.4～116.19API).The vertical lithology of the research area is mainly coal,mudstone,sandstone,and sandy mudstone.The horizontal distribution of coal seams is stable.The distribution of sandstone aquifers is uneven,and there are significant regional differences in well control water volume.The distribution of coal seams in the research area is relatively stable.Without considering the impact of secondary fracturing,the cumulative water production will be 1 200 m3 as the boundary line for whether coal seams receive external water supply.In the development process of coalbed methane wells,under similar structural and sedimentary conditions,the wider and larger the source and scale of coalbed water,the longer the gas occurrence time,the longer the duration of drainage and pressure reduction stage,and the higher the water production and lower the gas production.
coalbed methane developmentcoal measures waterLogging identificationcalculation modelwell control water volumeFanzhuang block
万方数据
维普
