In order to study the stress sensitivity of the coal and rock affected to the water production variation in coal reservoir,the indoor test was applied to evaluate the cracking affected to the stress sensitivity of coal and rock.A mathematical model was established to quantitatively characterize the stress sensitivity of coal and rock affected to the permeability.Based on the circumstances and the stress sensitivity of coal seam,a single-phase flow water production model was deduced by the previous data fitted,a prediction was made on the stress sensitivity of coal and rock affected to the water production volume.The study results showed that the permeability of coal and rock would be declined in the indexes with the effective stress increased,the stress sensitivity index of the cracking coal and rook was 0.172 ～ 1.482MPa-1and 0.064～0.096 MPa-1 higher than the non cracking coal and rock.Therefore,the complicated racking system of the coal and rock would be the root cause of the strong stress sensitivity.With the sensitivity coefficient of the stress increased,the water production curve would be changed from a continuous rising type to a first rising and falling type.And the higher the stress sensitivity coefficient,the shorter the water production rising section would be.%为了研究煤岩应力敏感性对煤储层产水量变化的影响,通过室内试验评价裂缝对煤岩应力敏感性的影响,建立了定量表征煤岩应力敏感性对渗透率影响的数学模型,在此基础上推导了基于煤层应力敏感性的单相流段产水量模型,进而在历史拟合基础上预测了煤岩应力敏感性对产水量的影响.研究结果表明:煤岩渗透率随有效应力增加呈指数衰减;裂缝性煤岩应力敏感性系数为0.172～1.482MPa-,远大于无裂缝煤岩的0.064～0.096 MPa-1,因此煤岩复杂裂缝系统是其强应力敏感性的根本原因;随着应力敏感性系数的增大,产水量曲线由持续上升型转变为先升后降型,且应力敏感性系数越大,产水量上升段越短.
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