Research On Spatio-temporal Evolution And Influencing Factors Of Physical Property Parameters Of Coal-bed Gas Vertical Well Combined Production In Superposed Gas-bearing System

Coalbed methane(CBM)as a new type of unconventional natural gas clean energy,can effectively alleviate the growing energy demand in China,for the prevention and control of environmental pollution,energy structure optimization plays a significant,is located in the eastern yunnan,Qian Xi has rich CBM resources reserves,its special contraposed the structure of the system,makes the research on CBM vertical Wells commingling method becomes extremely important,therefore,in this paper,through the use of independent research and development of superimposed CBM vertical Wells commingling test device,gas bearing system in different reservoir pressure gradient and different export pressure and bottom hole flowing pressure gradient under the condition of vertical Wells adopt the physical simulation experimental research on coalbed methane(CBM),The dynamic evolution of reservoir parameters,the stage division of main controlling factors of coal seam permeability and the productivity evolution of interbedded interference are compared.Through the above research,the following progress has been made:(1)Based on superimposed accumulation characteristics of special gas system,put forward superimposed system CBM vertical Wells commingling test method,through independent research and development system of superimposed gas CBM vertical Wells commingled production unit,can complete the effective simulation of the actual engineering geological conditions of reservoir parameters can be real-time monitoring of the collection of all,for different factors affecting CBM vertical Wells under the conditions of commingled production provide favorable means to test.(2)In different reservoir pressure gradient and different discharge pressure and bottom hole flowing pressure gradient under the condition of superimposed system CBM vertical Wells commingling test,think in the process of the multilayer reservoir fluid energy difference between is the main cause of the interlayer interference,by regulating reservoir pressure gradient and the export pressure and bottom hole flowing pressure gradient can effectively weaken the influence of the interlayer interference,improve the production capacity of the coal seam.(3)The coupling relationship between reservoir permeability and effective stress,coal body temperature and coal body deformation during coal-bed gas vertical well co-production is analyzed.Reservoir permeability shows a trend of decreasing first and then increasing during co-production.As a result of the combined effect of stress effect and matrix shrinkage effect,factors such as reservoir pressure gradient,wellbore outlet pressure and bottomhole flow pressure will affect the coupling relationship of permeability with temperature and coal body deformation,and increase the reservoir pressure gradient and bottomhole flow pressure Gradient and reducing the outlet pressure of the wellbore will prolong the effect time of effective stress under the condition that the main stress control factor affects reservoir permeability.