Study Of Stress Sensitivity Of Coal Reservoirs And Production Performance Prediction

Stress sensitivity of coal reservoirs is one of the most important factors affecting productionperformance of coalbed methane wells. Thus, it is necessary to research the impact of stresssensitivity of coal reservoirs on production performance and reduce or avoid its negative impact.Relying on the Qinshui South slope area, this paper applied the experiment research, theoryanalysis and numerical simulation to study the impact of temperature, water saturation and coalrank on stress sensitivity of coal reservoirs and establish the correlation between temperature,water saturation and coal rank with stress sensitivity of coal reservoirs. The results indicate thatpermeability decreases in the minus exponent function with the increase of net confining pressureand behaviors in different coal ranks. According to the existing permeability models, associatedwith the production performance of unsaturated CBM reservoirs, new models are established todescribe the permeability variation and indicate the impact of permeability variation on productionproductivity of CBM wells. The impact of the stress sensitivity of permeability, depth and gascontent/gas saturation on CBM production performance is simulated by numerious situmalationtechnology.